JP6092082B2 - Image processing apparatus and method, and image forming apparatus - Google Patents

Description

    The present invention relates to an image processing apparatus and method, and an image forming apparatus, and can be applied to an image processing apparatus such as a copying machine or a printer.

  In a conventional image processing apparatus (image forming apparatus) such as a copying machine or a printer, enlargement / reduction processing to a magnification specified by a user, or enlargement / reduction processing may be performed to fit an input image within a specified range. is there. For example, in the case of a copying machine, there is one that is enlarged or reduced at an arbitrary magnification of 25% to 400% according to user designation.

  As a conventional image enlargement / reduction processing method, for example, a simple enlargement method (simple reduction method), an interpolation enlargement / reduction method (bi-linear) method, an average reduction method, a cubic conversion method, and the like are known. These image enlargement / reduction methods both employ an interpolation method using adjacent pixels. In the conventional image processing apparatus, the difference in the interpolation method determines the image quality of the image data after the enlargement / reduction process.

  For example, Patent Document 1 describes an image processing apparatus that realizes image enlargement by hardware using a bi-linear method.

JP-A 61-227480

  However, in order to realize the conventional apparatus, it is necessary to prepare a line memory corresponding to the image width, and there is a problem that the cost of hardware increases as the size of the image to be processed increases.

  Therefore, an image processing apparatus and method that can efficiently change the size (enlargement and / or reduction) of an image, and an image forming apparatus are desired.

The image processing apparatus according to the first aspect of the present invention includes (1) a block image reading unit that extracts a plurality of block images from an input image and sequentially reads them, and (2) each of the block images read by the block image reading unit. And (3) a size obtained by resizing the input image at the predetermined magnification on the basis of the block image whose size has been changed by the size changing means. have a size-changed image generating means for generating a modified image, (4) the size change means for each line constituting the block image, performs a resizing process, (5) the size changing means changes the size The positional relationship between the position of the pixels that make up the block image line before processing and the position of the pixels that make up the line of the block image after resizing processing Using size change counter that manages, and performs a resize process for each line.

According to a second aspect of the present invention, in the image processing method performed by the image processing apparatus, (1) a block image reading unit, a size changing unit, and a size-changed image generating unit are provided. (2) the block image reading unit Extracting a plurality of block images and sequentially reading them out. (3) The size changing means performs a size changing process at a predetermined magnification for each of the block images read by the block image reading means. The resized image generating means generates a resized image obtained by resizing the input image at the predetermined magnification, based on the block image whose size has been changed by the resize means, and (5) the resized image The means performs a size changing process for each line constituting the block image. (6) The size changing means Using the position of the pixels constituting the lines of the block image, resizing counter for managing the positional relationship between the position of the pixels constituting the lines of a block image after resizing processing, performing the size changing process of each line It is characterized by.

According to a third aspect of the present invention, there is provided an image forming apparatus comprising: an image processing apparatus that processes an input image; and an image forming unit that forms an image processed by the image processing apparatus on a medium. (1) (1-1) A block image reading unit that extracts and sequentially reads out a plurality of block images from an input image, and (1-2) each of the block images read by the block image reading unit is sized at a predetermined magnification. (1-3) generating a size-changed image obtained by resizing the input image at the predetermined magnification on the basis of the block image whose size has been changed by the size-changing unit. have a size-changed image generating means, (1-4) wherein the size changing means for each line constituting the block image, performs a resizing process, (1- ) The size changing means includes a size change counter for managing a positional relationship between the positions of the pixels constituting the line of the block image before the size changing process and the positions of the pixels constituting the line of the block image after the size changing process. And performing a size changing process for each line .
An image processing apparatus according to a fourth aspect of the present invention includes: (1) a block image reading unit that extracts a plurality of block images from an input image and sequentially reads them; and (2) a block image that is read by the block image reading unit. And (3) a size obtained by resizing the input image at the predetermined magnification on the basis of the block image whose size has been changed by the size changing means. (4) In the block image reading unit, the size of the block image extracted from the input image is varied in accordance with the predetermined magnification, and the size of the block image is read from the input image. The size of the block image to be extracted is determined by the predetermined magnification.

  ADVANTAGE OF THE INVENTION According to this invention, the image processing apparatus which can change the size of an image efficiently can be provided.

FIG. 2 is a block diagram illustrating a functional configuration of an image forming apparatus equipped with the image processing apparatus according to the first embodiment. It is explanatory drawing (the 1) shown about the process of the block reading part which concerns on 1st Embodiment. 3 is a flowchart illustrating processing of the image forming apparatus according to the first embodiment. It is the flowchart shown about the parameter calculation process of the expansion / contraction part which concerns on 1st Embodiment. It is explanatory drawing (the 2) shown about the process of the block reading part which concerns on 1st Embodiment. It is explanatory drawing shown about the example of the process of the block expansion / contraction part which concerns on 1st Embodiment. It is explanatory drawing shown about the process of the block writing part which concerns on 1st Embodiment. It is the flowchart shown about the process at the time of the block enlarging / reducing part which concerns on 1st Embodiment performing the enlarging / reducing process for 1 line. FIG. 6 is a block diagram illustrating a functional configuration of an image forming apparatus equipped with an image processing apparatus according to a second embodiment. 6 is a flowchart illustrating processing of an image forming apparatus according to a second embodiment. FIG. 10 is an explanatory diagram illustrating processing limitations of each block image processing unit of an image forming apparatus according to a second embodiment. It is the flowchart shown about the size calculation of each block image calculated in the block expansion / contraction part which concerns on 2nd Embodiment. It is explanatory drawing shown about the specific example of the size of each block image which the block expansion / contraction part which concerns on 2nd Embodiment calculated. It is explanatory drawing shown about the process of the block reading part which concerns on 2nd Embodiment. It is explanatory drawing shown about the example of the process of the block expansion / contraction part which concerns on 2nd Embodiment. It is explanatory drawing shown about the process of the block writing part which concerns on 2nd Embodiment. FIG. 10 is a block diagram illustrating a functional configuration of an image forming apparatus equipped with an image processing apparatus according to a third embodiment. It is explanatory drawing shown about the example of operation | movement of the X direction expansion / contraction part 121B which concerns on 3rd Embodiment. 10 is a flowchart illustrating an overall operation of an image forming apparatus 1B according to a third embodiment. The overall processing of the parameter calculation method required for each part of the enlargement / reduction processing unit 100B according to the third embodiment will be described with reference to the flowchart of FIG. FIG. 10 is an explanatory diagram illustrating processing limitations of each block image processing unit of an image forming apparatus according to a third embodiment. It is explanatory drawing shown about the specific example of the size of each block image which the block expansion / contraction part which concerns on 3rd Embodiment calculated. It is explanatory drawing shown about the operation | movement of the block reading part which concerns on 3rd Embodiment. It is explanatory drawing shown about the process performed with respect to one block image in the previous resolution conversion part which concerns on 3rd Embodiment. It is explanatory drawing shown about the example of the expansion process with respect to the image block performed by the block expansion / contraction part which concerns on 3rd Embodiment. It is explanatory drawing shown about the process of the block image by the post-filter process part which concerns on 3rd Embodiment, a post-resolution conversion part, and a block cut process part. It is a block diagram which shows the functional structure of the image forming apparatus which concerns on 4th Embodiment. It is explanatory drawing shown about the image based on the image data displayed on the display of the thumbnail image output part which concerns on 4th Embodiment. It is the flowchart shown in detail about the reduction process of the X direction and Y direction which are performed in the thumbnail reduction part which concerns on 4th Embodiment.

(A) First Embodiment Hereinafter, an image processing apparatus and method and an image forming apparatus according to a first embodiment of the present invention will be described in detail with reference to the drawings.

(A-1) Configuration of First Embodiment FIG. 1A is a block diagram illustrating a functional configuration of an image forming apparatus 1 according to the first embodiment. FIG. 1B is a block diagram illustrating a functional configuration of the block enlargement / reduction unit 120 included in the image forming apparatus 1 according to the first embodiment.

  The image forming apparatus 1 includes an image input unit 10, a pre-filter processing unit 20, an enlargement / reduction processing unit 100, a post-filter processing unit 30, an image output unit 50, and an image memory 60.

  In the image forming apparatus 1, this embodiment includes components (the pre-filter processing unit 20, the enlargement / reduction processing unit 100, the post-filter processing unit 30, and the image memory 60) excluding the image input unit 10 and the image output unit 50. The image processing apparatus can be configured. In the image forming apparatus 1, at least the enlargement / reduction processing unit 100 is configured by hardware (for example, an integrated circuit such as an ASIC).

  The image input unit 10 has a function of receiving input of an image to be processed by the image forming apparatus 1. The method of holding the input image by the image input unit 10 is not limited. For example, an image input from an external device such as a scanner or a host PC via a network or various interfaces (for example, USB). May be obtained. Then, the image input unit 10 stores the acquired image data in the image memory 60. In FIG. 1, an image received by the image input unit 10 is illustrated as an image G101.

  The pre-filter processing unit 20 as pre-filter processing means performs a filter process that is performed before the processing of the enlargement / reduction processing unit 100 on the image G101. The pre-filter processing unit 20 performs a filter process on the data of the image G101 stored in the image memory 60 and writes the processed image data in the image memory 60. The pre-filter processing unit 20 includes, for example, a determination process for determining a Gaussian filter, a screen portion of the document, and the like, and performs a filter process for suppressing the occurrence of moire due to screen interference between the input document and the output document. In FIG. 1, an image after processing by the pre-filter processing unit 20 is illustrated as an image G102.

  The enlargement / reduction processing unit 100 performs enlargement or reduction processing (size change processing) on the image G102 processed by the pre-filter processing unit 20, and includes a block reading unit 110, a block enlargement / reduction unit 120, and A block writing unit 130 is provided. In FIG. 1, an image after processing by the enlargement / reduction processing unit 100 is illustrated as an image G103.

  The magnification (hereinafter referred to as “setting magnification”) related to the enlargement / reduction performed by the enlargement / reduction processing unit 100 may be determined by a user operation, for example, or may be determined by an external device (for example, a scanner or a host PC). Etc.) may be determined based on an instruction from the above.

  The block reading unit 110 serving as a block image reading unit converts the data of one page of the image G102 processed by the pre-filter processing unit 20 and written into the image memory 60 into the horizontal (width) direction (hereinafter referred to as “X direction”). Called) and a vertical (longitudinal) direction (hereinafter also referred to as “Y direction”), sequentially read as a block image divided into a plurality of blocks, and supplied to the block enlargement / reduction unit 120.

  FIG. 2 is an explanatory diagram showing the division of each block of the image performed by the block reading unit 110.

  As shown in FIG. 2, the block reading unit 110 generates M × N block images divided into N pieces in the X direction and M pieces in the Y direction for one page of the image G102. When the block reading unit 110 reads each block image, it is assumed that the line scanning is sequentially performed in the X direction from the upper left pixel and sequentially read. Specifically, the block reading unit 110 converts the upper left block image (0, 0) shown in FIG. 2 to (0, 1),... (0, N), (1, 0),. It is assumed that data are read in the order of M, N). When reading an image in block units, the block reading unit 110 sequentially changes the X-direction reading position and the Y-direction reading position.

  As described above, the enlargement / reduction processing unit 100 performs enlargement / reduction processing of the image G102 in units of block images, but simply divides the image G102 and performs enlargement / reduction processing as shown in FIG. Then, there is a risk that the image quality around the boundary of each block image is deteriorated (the pixel value is different from the case of processing in units of images for one page). Therefore, the block reading unit 110 of this embodiment reads an image including pixels around the block image (block image shown in FIG. 2) to be enlarged / reduced. That is, the enlargement / reduction processing unit 100 reads out each image block image so as to have an overlapping portion with an adjacent block. A specific example of the reading process of each block image by the block reading unit 110 will be described in detail in an operation description to be described later.

  The block enlargement / reduction unit 120 serving as a size change unit and a block management unit performs an enlargement / reduction process (size change process) at an arbitrary magnification on each block image read by the block reading unit 110. The block enlargement / reduction unit 120 includes an X direction enlargement / reduction unit 121 that performs enlargement / reduction in the X direction and a Y direction enlargement / reduction unit 122 that performs enlargement / reduction in the Y direction. First, enlargement / reduction in the X direction is performed, and then enlargement / reduction in the Y direction is performed.

  The X direction enlargement / reduction unit 121 includes an X direction enlargement / reduction counter 121a and an X direction output counter 121b.

  The X-direction enlargement / reduction unit 121 uses the X-direction output counter 121b to convert an arbitrary one line in the X direction constituting the input block image into a line of the output block image. Manage the pixels inside. Then, the X direction enlargement / reduction unit 121 uses the X direction enlargement / reduction counter 121a to determine the relative positional relationship between the pixel indicated by the X direction output counter 121b and the pixel on the line related to the input block image. to manage.

  The value of the X-direction enlargement / reduction counter 121a of the X-direction enlargement / reduction unit 121 is set to a counter initial value determined in advance for each block image at the head of the line (the head of the line of the block image). The X-direction enlargement / reduction unit 121 enlarges / reduces the line of the input block image according to the X-direction enlargement / reduction counter 121a, and outputs the number of pixels of the output line (output block image side) in the X direction. The counter 121b counts. The X-direction enlargement / reduction unit 121 enlarges / reduces the input block image in the X direction by outputting only pixels within a predetermined value range determined in advance by the X-direction output counter 121b. The X direction enlargement / reduction unit 121 inputs the block image that has been enlarged / reduced in the X direction to the Y direction enlargement / reduction unit 122.

  Similar to the X direction enlargement / reduction unit 121, the Y direction enlargement / reduction unit 122 includes a Y direction enlargement / reduction counter 122a and a Y direction output counter 122b.

  The value of the Y-direction enlargement / reduction counter 122a of the Y-direction enlargement / reduction unit 122 is set to a counter initial value determined in advance for each block image at the head of the line (line head of the block image). The Y-direction enlargement / reduction unit 122 enlarges / reduces the line of the input block image according to the Y-direction enlargement / reduction counter 122a, and outputs the number of pixels to be output (number of lines on the output block image side) as the Y-direction output. The counter 122b counts. Then, the Y direction enlargement / reduction unit 122 outputs only pixels (lines) within a predetermined value range determined in advance by the Y direction output counter 122b, thereby enlarging / reducing the input block image in the Y direction. The image is reduced and supplied to the block writing unit 130 as an output block image.

  Note that the Y-direction enlargement / reduction unit 122 performs memory for one block image (line memory) when performing enlargement / reduction processing by an enlargement / reduction method other than simple reduction (for example, interpolation enlargement / reduction method). It is necessary to have multiple.

  The block writing unit 130 serving as the size-changed image generating unit sequentially writes the block images that have been enlarged / reduced by the block enlargement / reduction unit 120 to the image memory 60 (the region of the image G103). In the block image input to the block writing unit 130, overlapping pixels between blocks are cut by the preceding process (the process of the block enlargement / reduction unit 120).

Further, since the width and height of each block are constant, the block writing unit 120 writes the block image to the image memory 60 at a constant interval in the X direction and the Y direction, so that the image G103 for one page is written. Create data.

  The post-filter processing unit 30 as post-filter processing means performs filter processing performed after the processing of the enlargement / reduction processing unit 100, and the data of the image G103 input by the enlargement / reduction unit 10 from the image memory 60 is processed. The data is read and filtered, and the processed image data is written in the image memory 60. The post-filter processing unit 30 is configured by, for example, color conversion processing, edge enhancement processing, and the like, and performs filter processing such as converting image data into four colors of CMYK and performing edge enhancement in order to clarify characters and the like in a document. I do. In FIG. 1, an image after processing by the post filter processing unit 30 is illustrated as G104.

  The image output unit 50 has a function of reading the data of the image G104 generated by the post-filter processing unit 30 from the image memory 60 and outputting it. The output means by the image output unit 50 is not limited. For example, the image G104 is printed out (image formation) on a recording medium (printing paper or the like) by an electrophotographic image forming unit (printing unit). Also good.

  In this embodiment, in order to simplify the description, the pixel value of each pixel constituting each image (G101 to G104) processed by the image forming apparatus 1 is an image indicated by one component (for example, brightness). However, the number of components of each image processed by the image forming apparatus 1 is not limited. For example, when each image processed by the image forming apparatus 1 is represented by three components R, G, and B, each of the three component images is subjected to enlargement / reduction processing, and the image output unit 50 performs the three components. You may make it perform the output based on an image.

(A-2) Operation of the First Embodiment Next, the operation (image processing method of the embodiment) of the image forming apparatus 1 of the first embodiment having the above-described configuration will be described.

(A-2-1) Overview of Overall Operation of Image Forming Apparatus 1 FIG. 3 is a flowchart showing the overall operation of the image forming apparatus 1.

  First, in the image forming apparatus 1, it is assumed that image data is input to the image input unit 10 and written as an image G <b> 101 in the image memory 60. It is assumed that the set magnification is set in the enlargement / reduction processing unit 100 (S101).

  Here, it is assumed that the image G101 is an image having a width of 7680 pixels and a height of 5120 pixels. Further, here, the enlargement / reduction processing unit 100 is classified into a case where 133% (enlarged by 133/100) is set as a set magnification and a case where 41% (reduced by 41/100) is set. I will explain.

  Next, the pre-filter processing unit 20 performs pre-filter processing on the image G101, and the processed image G102 is written in the image memory 60 (S102). It is assumed that the image size does not change in the processing of the pre-filter processing unit 20 (that is, the size of the image G102 is the same as that of the image G101).

  Then, the enlargement / reduction processing unit 100 (block enlargement / reduction unit 120) prepares for calculation of each parameter related to enlargement / reduction based on the size of the image G102 to be enlarged / reduced and the set magnification. (S103).

  Then, the enlargement / reduction processing unit 100 executes read processing, enlargement / reduction processing, and write-out processing in units of blocks, and the processed image G103 is written to the image memory 60 (S104).

  Then, the post-filter processing unit 30 executes post-filter processing on the image G103 after the enlargement / reduction processing, and the processed image G104 is written in the image memory 60 (S105). It is assumed that the image size does not change in the processing of the post-filter processing unit 30 (that is, the size of the image G104 is the same as that of the image G103).

  Then, the image output unit 50 outputs the post-filter processed image G104 (S106).

(A-2-2) Calculation of parameters related to enlargement / reduction (step S103)
Next, details of the parameter calculation processing performed by the block enlargement / reduction unit 120 in step S103 will be described with reference to the flowchart of FIG.

  First, the block enlargement / reduction unit 120 calculates the size (width and height of the output image of one page) of the image G103 output after the enlargement / reduction processing based on the image G102 and the set magnification (S201). Specifically, the block enlargement / reduction unit 120 can calculate the size of the image G103 by the following equations (1) and (2).

  In the following expressions (1) and (2), XO is the number of pixels in the width (X direction) of the output image G103. XI is the number of pixels in the width (X direction) of the processing target image G102. Furthermore, YO is the number of pixels in the height (Y direction) of the output image G103. Furthermore, YI is the number of pixels in the height (Y direction) of the image G102 to be processed. Further, xratio and yratio are numerators having set magnifications in the X direction and the Y direction, respectively. Further, xbase and ybase are denominators of set magnifications in the X direction and the Y direction, respectively.

XO = (XI) × (xratio) / (xbase) (1)
YO = (YI) × (yratio) / (ybase) (2)
Note that the block enlargement / reduction unit 120 truncates the decimal part when a value below the decimal point is generated when the above formulas (1) and (2) are calculated. Note that the mathematical formulas described below will be described assuming that the calculation is performed with the decimal part rounded down without particular notice.

  In this example, as described above, the size of the input image G102 is the width 7680, the height 5120, and the set magnification is 133%. Therefore, the width XO of the output image G103 is 7680 × 133/100 = 10214 according to the above equation (1). The height YO of the image G103 to be output is 5120 × 133/100 = 6809 according to the above equation (2). When the set magnification is 41%, the output image G103 has a width XO of 7680 × 41/100 = 3148 and a height YO of 5120 × 41/100 = 2999.

  Next, the block enlargement / reduction unit 120 calculates the size of the input block image input to the block enlargement / reduction unit 120 and the size of the output block image output from the block enlargement / reduction unit 120 (S102). In other words, in the first embodiment, the size of the input block image is the size of the block image that the block reading unit 110 reads from the image G102. In the first embodiment, the size of the output block image is the size of the block image that the block writing unit 130 writes to the image G103.

  The sizes of the input block image and the output block image calculated by the block enlargement / reduction unit 120 vary depending on the set magnification and the upper limit of the block image size that can be processed by each processing unit constituting the enlargement / reduction processing unit 100. The upper limit of the block image size (the width or height of the block image) is, for example, the upper limit of the number of pixels that can be held by resources such as a memory (for example, a line memory) provided in the block enlargement / reduction unit 120. For example, since the block enlargement / reduction unit 120 processes each image block in units of lines in the X direction and the Y direction, the number of pixels that can be stored in the memory included in the block enlargement / reduction unit 120 is equal to the block image to be processed. It becomes the upper limit of the width and height. Here, it is assumed that the number of pixels that can be held in the line memory of the block enlargement / reduction unit 120 is 256. In the following description, it is assumed that the width and height of each block image have the same number of pixels, but the ratio of the width and height of each block image is not limited.

  As described above, the block enlargement / reduction unit 120 sets the size of the block image input to the enlargement / reduction processing unit 100 so as not to exceed the processing upper limit when the enlargement / reduction processing unit 100 performs processing in units of block images. decide.

  Hereinafter, the upper limit of the width and height of the output block image processed by the block enlargement / reduction unit 120 is 256 pixels. Therefore, when performing the enlargement process on the input block image, the block enlargement / reduction unit 120 needs to determine the size of the input block image so that the width and height do not exceed 256 after the enlargement process.

  Specifically, the block enlargement / reduction unit 120 can determine appropriate sizes of the input block image and the output block image, for example, by the following processing.

  First, the block image size output from the block enlargement / reduction unit 120 is a width 256 and a height 256 under the above-described conditions. The above-described width and height are used as upper limit values of the X direction output counter 121b and the Y direction output counter 122b of the enlargement / reduction unit 120. Therefore, the block image size read by the block reading unit 110 can be determined by the following equations (3) and (4).

  In the following equations (3) and (4), inbw and inbh are the width and height of the block image input to the block enlargement / reduction unit 120. Outbw and outbh are the width and height of the block image output by the block enlargement / reduction unit 120. Furthermore, ulwR and ullhD represent the width and height of invalid pixels (regions overlapping with adjacent block images) generated at the right and bottom edges of the block image when the block enlargement / reduction unit 120 performs enlargement / reduction. When the interpolation enlargement / reduction method is used for enlargement / reduction performed by the block enlargement / reduction unit 120, for example, “1” can be applied to ulwR and ulhD.

inbw = (outbw × xbase + xratio−1)
/ Xratio + nulwR (3)
inbh = (outbh × ybase + yratio−1)
/ Yratio + nullhD (4)
In this example, as described above, the size of the input image G102 is the width 7680, the height 5120, and the set magnification is 133%. Therefore, the width and height of the input block image are 194. When the set magnification is 41%, the width and height of the input block image are 626.

  Next, the block enlargement / reduction unit 120 calculates the number of block image divisions for the image G102 based on the size of the input block image calculated in step S202 (S203).

  Specifically, the block enlargement / reduction unit 120 can calculate the number of divisions in the X direction and the Y direction with respect to the image G102 by the following equations (5) and (6).

(X direction division number) = (XO−1) / (outbw) +1 (5)
(Y direction division number) = (YO-1) / (outbh) +1 (6)
In this example, as described above, the input image G102 has a width of 7680 and a height of 5120. Therefore, when the set magnification is 133% (133/100), the width and height of the input block image are 194, so the number of divisions in the X direction is 40 and the number of divisions in the Y direction is 27. When the set magnification is 41% (41/100), the width and height of the input block image are 626, so the number of divisions in the X direction is 13, and the number of divisions in the Y direction is 9.

  Then, the block enlargement / reduction unit 120, for each block image, the initial values of the X direction enlargement / reduction counter 121a and the Y direction enlargement / reduction counter 122a and the X of each block image read by the block reading unit 110. The reading position in the direction and the Y direction is calculated (S204). The initial value of the Y direction enlargement / reduction counter 122a, the initial value of the Y direction enlargement / reduction counter 122a, the readout position in the X direction, and the readout position in the Y direction should be calculated by the following equations (7) to (14), respectively. Can do.

  In the following formulas (7) to (14), xno and yno represent a block number in the X direction and a block number in the Y direction, respectively. Also, xcnt0 [? ], Ycnt0 [? ] Represents the initial value of the X-direction enlargement / reduction counter 121a corresponding to the block number in the X direction and the initial value of the Y-direction enlargement / reduction counter 122a corresponding to the block number in the Y direction, respectively.

The above “?” Represents an arbitrary block number (the same applies hereinafter). Furthermore, xpoS0 [? ], YpoS0 [? ] Represents the X-direction read position corresponding to the X-direction block number and the Y-direction read position corresponding to the Y-direction block number, respectively. Furthermore, outbw and outbh are the width and height of the output block image calculated in step S202 described above. Further, “%” in the following formulas (7) to (14) is an operator representing a remainder operation. The block enlargement / reduction unit 120 uses the following formulas (7) to (14) to increase / decrease the counter in order from the leftmost block in the X direction and from the uppermost block in the Y direction. The initial value and the reading position are calculated.

[Calculation formula for enlargement / reduction counter in X direction]
xcnt0 [0] = 0 (7)
xcnt0 [xno] =
(Outbw × xbase + xcnt0 [xno−1])% xratio (8) [Calculation formula of enlargement / reduction counter in Y direction]
ycnt0 [0] = 0 (9)
ycnt0 [yno] =
(Outbh × ybase + ycnt0 [yno−1])% yratio (10)
[Reading position in X direction]
xpoS0 [0] = 0 (11)
xpoS0 [xno] = xpoS0 [xno-1]
+ (Outbw × xbase + xcnt0 [xno−1]) / xratio (12)
[Reading position in Y direction]
ypos0 [0] = 0 (13)
ypos0 [yno] = ypoS0 [yno-1]
+ (Outbh × ybase + ycnt0 [yno−1]) / yratio (14)
As described above, the block enlargement / reduction unit 120 calculates each parameter related to enlargement / reduction.

(A-2-3) Input Block Image Reading Process by Block Reading Unit 110 Next, details of the input block reading process performed by the block reading unit 110 in step S104 described above will be described with reference to FIG. .

  FIG. 5 is an explanatory diagram showing processing when the block reading unit 110 reads the image G102 input to the enlargement / reduction processing unit 100 in units of input blocks according to the parameters determined in step S103 described above. In FIG. 5, the size of the input image G102 is shown for the case where the width is 7680, the height is 5120, and the set magnification is 133%.

  As shown in FIG. 5A, the input block image read by the block reading unit 110 is read so as to have an overlapping portion with an adjacent input block image. In FIG. 5A, the position of the leftmost pixel of the input image G102 in the X direction is represented as 0, and the position of the uppermost pixel in the Y direction is represented as 0. Then, the reading start position in the X direction of the input block image divided by the block reading unit 110 is 0, 192, 384, corresponding to the block numbers 0, 1, 2, 3, 4,. 577, 769, and so on. Also, the reading start position in the Y direction of the input block image divided by the block reading unit 110 is 0, 192,... Corresponding to the block numbers 0, 1,. For example, if the input block image has an X-direction block number of 2 and a Y-direction block number of 1, the readout position in the X-direction and the Y-direction is (384, 192). In addition, the size of each input block image to be read is common to all the input block images (in the example of FIG. 5B, width 194 × height 194). Then, the block readout unit 110 reads out each input block image while changing the readout position in the X direction and the Y direction according to the block number in the X direction and the Y direction of each input block image, and reads the read input block image. This is supplied to the block enlargement / reduction unit 120.

(A-2-4) Enlargement / Reduction Process by Block Enlargement / Reduction Unit 120 Next, the enlargement / reduction process for each input block image performed by the block enlargement / reduction unit 120 in step S104 will be described.

  FIG. 6 is an explanatory diagram showing an example of enlargement / reduction processing for each input block image performed by the block enlargement / reduction unit 120. In FIG. 6, the input block image (width 194 × height 194) shown in FIG. 5 is subjected to enlargement / reduction processing with a set magnification of 133%, and converted to an output block image (width 256 × height 256). An example is shown.

  First, in the block enlargement / reduction unit 120, the block image (block image) enlarged in the X direction by the X direction enlargement / reduction unit 121 for the input block image (width 194 × height 194) shown in FIG. The size is 256 (width × height 194) (see FIG. 6B).

  Then, in the block enlargement / reduction unit 120, the block image (image block shown in FIG. 6B) enlarged in the X direction is enlarged in the Y direction by the Y direction enlargement / reduction unit 122. As a block image size, width 256 × height 256) is generated (see FIG. 6C). Then, the block enlargement / reduction unit 120 supplies the block image processed by the Y direction enlargement / reduction unit 122 to the block writing unit 130 as an output block image.

  Next, details of the processing of the X direction enlargement / reduction unit 121 will be described.

  In the processing by the X direction enlargement / reduction unit 121 described above, the X direction enlargement / reduction counter 121a is the initial value of the enlargement / reduction counter corresponding to the block number in the X direction related to the block image at the head of the line of each block image. (Xcnt0 [xno]). For example, if the block number in the X direction is 2, it is set to 128. The enlargement process is performed for each line according to the above-described enlargement / reduction counter, and the X-direction output counter 121b is enlarged and output until a predetermined value (256 in the example) is reached. Further, as shown in FIG. 6D, in the enlargement / reduction process in the X direction, if there is an extra pixel (invalid pixel) at the right end of the block image, it is ignored (excluded).

  Next, details of the processing of the Y direction enlargement / reduction unit 122 will be described.

  In the processing by the Y-direction enlargement / reduction unit 122 described above, the Y-direction enlargement / reduction counter 122a is the initial value of the enlargement / reduction counter corresponding to the block number in the Y direction related to the block image on the first line of each block image ( ycnt0 [yno]). For example, if the block number in the Y direction is 1, it is set to 64. In accordance with the above-described enlargement / reduction counter, enlargement processing is performed for each line, and the output counter is enlarged and output until a predetermined value (256 in the example) is reached. Further, as shown in FIG. 6E, in the enlargement / reduction process in the X direction, if there is an extra pixel (invalid pixel) at the lower end of the block, it is ignored (excluded).

  Then, the enlargement / reduction processing for one line by the X-direction enlargement / reduction unit 121 can be specifically expressed by a flowchart as shown in FIG. Regarding the processing of the Y-direction enlargement / reduction unit 122, the processing similar to that of the X-direction enlargement / reduction unit 121 can be applied only by changing the direction of the line to be processed. Is omitted.

  In FIG. 8, xocnt represents the X direction output counter 121b, xcnt represents the X direction enlargement / reduction counter 121a, and xcnt0 represents the initial value of the X direction enlargement / reduction counter 121a associated with the block image to be processed. In FIG. 8, xicnt is a counter that manages the position (pixel) on the line in the X direction on the side of the input block image to be referred to. Furthermore, in FIG. 8, vo [xocnt] indicates the pixel value at the position of xocnt (pixel value of the xocnt-th pixel counted from the left end) on the line in the X direction on the output block image side.

  First, it is assumed that the X direction enlargement / reduction unit 121 extracts pixel values for one line in the X direction from the input block image. Then, the X-direction enlargement / reduction unit 121 initializes each variable (xocnt = 0, xcnt = xcnt0, xicnt = 0) (S301).

  Then, the X direction enlargement / reduction unit 121 determines whether xcnt (a value of the enlargement / reduction counter) is smaller than xratio (a numerator value of the set magnification). The X direction enlargement / reduction unit 121 operates from the process of step S303 described later when xcnt is smaller than xratio, and operates from the process of step S305 described later otherwise.

  If it is determined in step S302 described above that xcnt is smaller than xratio, the X-direction enlargement / reduction unit 121 obtains a pixel value vo [xocnt] of the output pixel, increments xocnt (adds 1), Further, a process of adding xbase to xcnt is performed (S303).

  Here, the pixel value vo [xocnt] of the output pixel can be obtained by, for example, the following equation (15) in the case of the interpolation enlargement / reduction method. In the following equation (15), vi [xicnt] indicates the pixel value at the xicnt position (pixel value of the xicnt-th pixel counted from the left end) on the line in the X direction on the input block image side. Yes. Further, vi [xicnt + 1] indicates the pixel value at the position of xicnt + 1 (the pixel value of the xicnt + 1-th pixel counted from the left end) on the line in the X direction on the input block side.

vo [xocnt] =
((Vi [xicnt]) × (xratio−xcnt)
+ (Vi [xicnt + 1]) × (xcnt)) / (xbase) (15)
Then, the X direction enlargement / reduction unit 121 determines whether or not the value of xcnt is greater than or equal to xratio, and only when the value of xcnt is greater than or equal to xratio, the process of subtracting xratio from xcnt, and the input pixel position Update processing (increment of xicnt) is performed (S305).

  Then, the X direction enlargement / reduction unit 121 determines whether or not the value of the output counter xocnt has reached outbw (the number of output pixels of the line in the X direction in one output block image) (S306). When xocnt has reached outbw, the X-direction enlargement / reduction unit 121 ends the process related to the line, and when xocnt has not reached outbw, the X direction enlargement / reduction unit 121 returns to step S302 to enter the line. Continue such processing.

  The X-direction enlargement / reduction unit 121 can perform the above-described flowchart processing on all the X-direction lines related to each block image, and can enlarge or reduce the input block image in the X-direction.

(A-2-5) Writing Process by Block Writing Unit 130 Next, the block image writing process performed by the block writing unit 130 in the above-described step S104 will be described.

  FIG. 7 is an explanatory diagram showing a block image writing operation to the image memory 60 by the block writing unit 130.

  As shown in FIG. 7, the block image input to the block writing unit 130 is an image G103 for one page at a constant interval in the X and Y directions (256 in the X direction and 256 in the Y direction). It is written in the memory 60.

(A-3) Effects of First Embodiment According to the first embodiment, the following effects can be achieved.

  The image forming apparatus 1 is not a line memory that holds pixels corresponding to the page width or height (width or height of the output image G104) but a line memory that holds pixels corresponding to the width of the block image obtained by dividing the page. The enlargement / reduction process at an arbitrary magnification can be performed. Therefore, in the image forming apparatus 1, even if the size (number of pixels) of the image to be input or output increases, processing can be performed (efficiently) without adding resources such as a memory.

(B) Second Embodiment Hereinafter, an image processing apparatus and method and an image forming apparatus according to a second embodiment of the present invention will be described in detail with reference to the drawings.

(B-1) Configuration of Second Embodiment In the first embodiment, filter processing is performed before and after the enlargement / reduction processing unit 100, and image data is read out from the image memory 60 in each filter processing. And writing has occurred. Therefore, in the image forming apparatus 1 according to the first embodiment, it is necessary to secure a memory area in the image memory 60 for holding image data for each filter process. In the image processing apparatus, it is considered that only one large-scale memory such as a DRAM is normally used as a memory for storing image data, and the amount of data that can be accessed per unit time is limited. Therefore, in the image forming apparatus 1 of the first embodiment, efficient image processing can be performed by reducing the number of times image data is read from and written to the image memory 60.

  Therefore, the image forming apparatus 1A according to the second embodiment shown in FIG. 9 is configured to reduce the number of accesses to the image memory 60 by performing the filtering process in units of block images.

  FIG. 9A is a block diagram illustrating a functional configuration of the image forming apparatus 1A according to the second embodiment. The same or corresponding parts as those in FIG. The code | symbol is attached | subjected. FIG. 9B is a block diagram illustrating a functional configuration of the block enlargement / reduction unit 120A included in the image forming apparatus 1A according to the second embodiment, and is the same as or corresponds to the above-described FIG. The parts are given the same or corresponding symbols.

  Hereinafter, the difference between the second embodiment and the first embodiment will be described.

  The image forming apparatus 1A according to the second embodiment includes an image input unit 10, an enlargement / reduction processing unit 100A, an image output unit 50, and an image memory 60. The enlargement / reduction processing unit 100A includes, in order from the previous stage, a block reading unit 110A, a pre-filter processing unit 140, a block enlargement / reduction unit 120A, a post-filter processing unit 150, a block cut processing unit 160, and a block writing unit 130A. Is arranged. Hereinafter, each component (block reading unit 110A, pre-filter processing unit 140, block enlargement / reduction unit 120A, post-filter processing unit 150, block cut processing unit 160, which processes a block image in the enlargement / reduction processing unit 100A, The block writing unit 130A) is collectively referred to as a “block image processing unit”.

  That is, the image forming apparatus 1A according to the second embodiment is different from the first embodiment in that the enlargement / reduction processing unit 100A includes components that perform pre-filter processing and post-filter processing in units of blocks. Is different. Specifically, in the image forming apparatus 1A according to the second embodiment, the enlargement / reduction processing unit 100A performs pre-filter processing in units of block images between the block reading unit 110A and the block enlargement / reduction unit 120A. A pre-filter processing unit 140 is inserted. In the enlargement / reduction processing unit 100A of the second embodiment, a post-filter processing unit 150 that performs post-filter processing in units of blocks between the block enlargement / reduction unit 120A and the block writing unit 130A, and a post-filter A block cut processing unit 160 for cutting unnecessary portions used for processing is inserted. The block reading unit 110A is different from the first embodiment in that the block image is directly read out from the input image G101. Therefore, in the second embodiment, an image processing apparatus is configured by the enlargement / reduction processing unit 100A.

  Accordingly, unlike the first embodiment, the image input unit 10A of the second embodiment processes the image G102 that has been subjected to the pre-filter process and the image G103 that has been subjected to the enlargement / reduction process without being written to the image memory 60. Thus, efficient processing is possible in terms of memory access.

  The block reading unit 110A reads the image G101 in units of block images according to the parameters determined by the block enlargement / reduction unit 120A and supplies the image G101 to the pre-filter processing unit 140.

  Then, the pre-filter processing unit 140 as the pre-filter processing means in the second embodiment performs the filter processing in units of block images and supplies the filtered block image to the block enlargement / reduction unit 120A. As the specific filter processing performed by the pre-filter processing unit 140, various image data filter processing (block image unit filter processing) can be applied, and thus detailed description thereof is omitted.

  The block enlargement / reduction unit 120A performs enlargement / reduction processing on the block image supplied from the pre-filter processing unit 140, and supplies the result to the post-filter processing unit 150. The block enlargement / reduction unit 120A includes an X direction enlargement / reduction unit 121A and a Y direction enlargement / reduction unit 122A. In the X direction enlargement / reduction unit 121A (Y direction enlargement / reduction unit 122A), the X direction skip counter 121c (Y direction skip counter 122c) is added in accordance with the insertion of the pre-filter processing unit 140. This is different from the first embodiment. The X-direction skip counter 121c and the Y-direction skip counter 122c skip (exclude; ignore) the invalid pixels (first invalid areas) at the left end and the upper end of each block image input to the block enlargement / reduction unit 120A. This counter is reset at the head of the line of the block image in the same manner as the output counter.

  Then, the block enlargement / reduction unit 120A performs the first embodiment with respect to an area excluding the area skipped by the above-described skip counter (the X-direction skip counter 121c and the Y-direction skip counter 122c) for the input block image. The same enlargement / reduction process is executed, and the block image after the enlargement / reduction process is supplied to the post-filter processing unit 150.

  Then, the post-filter processing unit 150 as the post-filter processing unit in the second embodiment performs post-filter processing on the block image supplied from the post-filter processing unit 150, and performs block filtering on the block image that has been post-filtered. This is supplied to the processing unit 160. As the specific filter processing performed by the post-filter processing unit 150, various image data filter processing (block image unit filter processing) can be applied, and thus detailed description thereof is omitted.

  Then, the block cut processing unit 160 serving as a block cut unit cuts (excludes) the invalid pixels (second invalid region) around the block image generated by the post filter processing from the block image supplied from the post filter processing unit 150. ) And supply it to the block writing unit 130A.

  Then, the block writing unit 130A sequentially writes the block images subjected to the block cut processing to the image memory 60 (the region of the image G104) to create data of the image G104. Since the writing process itself performed by the block writing unit 130A for each block image is the same process as in the first embodiment, detailed description thereof is omitted.

(B-2) Operation of Second Embodiment Next, an operation (image processing method of the embodiment) of the image forming apparatus 1A of the second embodiment having the above-described configuration will be described.

(B-2-1) Outline of Overall Operation of Image Forming Apparatus 1A FIG. 10 is a flowchart showing the overall operation of the image forming apparatus 1A.

  First, in the image forming apparatus 1A, it is assumed that the data of the image G101 is input to the image input unit 10 and is written in the image memory 60 as the image G101. Then, it is assumed that the set magnification is set in the enlargement / reduction processing unit 100A (S401).

  Here, it is assumed that the image G101 is an image having a width of 7680 pixels and a height of 5120 pixels. Further, here, the case where 133% is set as the set magnification in the enlargement / reduction processing unit 100 and the case where 41% is set will be described separately.

  Then, the enlargement / reduction processing unit 100A (block enlargement / reduction unit 120A) prepares for calculation of each parameter related to enlargement / reduction based on the size of the image G101 to be enlarged / reduced and the set magnification. (S402).

  Then, the enlargement / reduction processing unit 100A performs a read process, a pre-filter process, an enlargement / reduction process, a post-filter process, a block cut process, and a write process for each block, and the processed image G104 is stored in the image memory 60. Is written (S403).

  Then, the image output unit 50 outputs the processed image G104 (S404).

(B-2-2) Parameter calculation related to enlargement / reduction (step S402)
Next, details of the parameter calculation process performed in the block enlargement / reduction unit 120A in step S402 described above will be described.

  Here, the pre-filter processing unit 140, the block enlargement / reduction unit 120A, and the post-filter processing unit 150 each include a line memory that holds pixels of 288, 264, and 262 pixels, and the number of pixels is the number of each processing unit. It is assumed that there is an upper limit of the block image width that can be output. Also, here, the pre-filter processing unit 140 performs a filter process for referring to a 25 × 25 pixel around the target pixel, and the post-filter processing unit 150 performs a filter for referring to a 7 × 7 pixel around the target pixel. It is assumed that processing is performed.

  The parameter calculation processing by the block enlargement / reduction unit 120A can also be described with reference to the flowchart of FIG.

  First, in step S201, the block enlargement / reduction unit 120A sets the size of the image G104 to be output after the enlargement / reduction processing (the width and height of the output image of one page) based on the image G101 and the set magnification. The calculation is performed using the above equations (1) and (2) as in the embodiment.

  In this example, as described above, the size of the input image G101 is the width 7680, the height 5120, and the set magnification is 133%. Accordingly, the output image G104 has a width XO of 10214 and a height of YO of 6809. Furthermore, when the set magnification is 41%, the output image G104 has a width XO of 3148 and a height YO of 2099.

  In step S202, the block enlargement / reduction unit 120 calculates the size of each block image input / output by each block image processing unit in the enlargement / reduction processing unit 100A.

  The input / output block image size is the width and height of the input / output block image in each block image processing unit of the enlargement / reduction processing unit 100A. In the second embodiment, the block image size read by the block reading unit 110A The block image size output from the filter filter processing unit 20, the block image size output from the block enlargement / reduction unit 120A, the block image size output from the post-filter processing unit 150, and the block image size output from the block cut processing unit 160 ( This corresponds to the block image size written by the block writing unit 130). The block image size calculated by the enlargement / reduction processing unit 100A includes the enlargement / reduction magnification, the upper limit of the block image size that can be output by each block image processing unit, and the invalid portion of the block image outer periphery generated by each block image processing unit. Fluctuates depending on the pixel width and height.

  FIG. 11 illustrates the upper limit of the block image size that can be output by each block image processing unit of the enlargement / reduction processing unit 100A and the pixel width and height of the invalid portion generated on the outer periphery of the block image in the example of the second embodiment. It is explanatory drawing which showed.

  As described above, the upper limit of the block image width is set in the pre-filter processing unit 140, the block enlargement / reduction unit 120A, and the post-filter processing unit 150, and is 288, 264, and 262, respectively. As for the upper limit of the block image height, the same restrictions as in the first embodiment are assumed, and it is assumed that there is a limit of 256 heights in the writing of the block writing unit 130.

  In addition, invalid pixels generated in the outer periphery of the block image are generated in the pre-filter processing unit 140, the post-filter processing unit 20, and the block enlargement / reduction unit 120A. Specifically, in this example, the front filter processing unit 140 generates 12 pixels at the left end, the right end, the upper end, and the lower end, and the rear filter processing unit 150 generates 3 pixels at the left end, the right end, the upper end, and the lower end. The enlargement / reduction unit 120A generates one pixel at the right end and the lower end (when the interpolation enlargement / reduction method is used).

  As described above, in step S202 described above, the block enlargement / reduction unit 120A has a block image size upper limit input / output in each block image processing unit in the enlargement / reduction processing unit 100A and invalid pixels generated at the outer periphery of the block image. The output block image size in each block image processing unit is calculated using the number and the set magnification.

  FIG. 12 is a flowchart showing an operation in which the block enlargement / reduction unit 120A calculates each parameter in step S202 described above.

  A variable p in FIG. 12 is a variable used by the block enlargement / reduction unit 120A to manage the process numbers related to the components (each processing stage) in the enlargement / reduction processing unit 100A. p corresponds to the processing number in FIG. Therefore, as shown in FIG. 11, in the block reading unit 110A, the first (frontmost) processing stage (p = 0) is the block reading unit 110A, and the second processing stage (p = 1) is the pre-filter. The processing unit 140, the third processing stage (p = 2) is the block enlargement / reduction unit 120A, the fourth processing stage (p = 3) is the post-filter processing unit 150, and the fifth processing stage (p = 4) is the block cut processing unit 160, and the sixth (last) processing stage (p = 5) is the block writing unit 130A.

  First, the block enlargement / reduction unit 120A provisionally determines the output block image size of the last stage processing (S501). In this case, the value used for provisional determination by the block enlargement / reduction unit 120A is, for example, the output image size obtained in step S201 described above.

  Next, the block enlargement / reduction unit 120A sets “5” as the process number of the last stage in p (S502).

  Next, the block enlargement / reduction unit 120A calculates the output block image size of the process with the process number p (S503). Here, the output block image size in each block image processing unit is calculated. However, since the output block image size of the block enlargement / reduction unit 120A cannot be calculated from the output block image size of the previous processing, The calculation of the output block image size in the block image processing unit needs to be calculated in order from the output block image size in the subsequent processing. The calculation of the output block image size for each processing number (each block image processing unit) in the second embodiment can be obtained by the following equations (16) to (27).

[Block writing unit 130A, p = 5]
outbw [p] = arbitrary value (16)
outbh [p] = arbitrary value (17)
[Block cut processing unit 160, p = 4]
outbw [p] = outbw [p + 1] (18)
outbh [p] = outbh [p + 1] (19)
[Post-filter processing unit 150, p = 3]
outbw [p] =
outbw [p + 1] + nullL [p] + nullR [p] (20)
outbh [p] =
outbh [p + 1] + nullh [p] + nullhD [p] (21)
[Block enlargement / reduction unit 120A, p = 2]
outbw [p] = outbw [p + 1] (22)
outbh [p] = outbh [p + 1] (23)
[Pre-filter processing unit 140, p = 1]
outbw [p] =
(Outbw [p + 1] × xbase + xratio−1) / xratio
+ NulwL [p] + nulwR [p] + nulwL [p + 1]
+ NulwR [p + 1] (24)
outbh [p] =
(Outbh [p + 1] × ybase + yratio−1) / yratio
+ NullU [p] + nullh [p] + nullh [p + 1]
+ NullhD [p + 1] (25)
[Block reading unit 110A, p = 0]
outbw [p] = outbw [p + 1] (26)
outbh [p] = outbh [p + 1] (27)
As shown in the above equation, the width (outbw [p]) of the output block image and the height (outbw [p]) of the output image in each block image processing unit are calculated. Note that the output block image size of the block writing unit 130, which is the last stage process, is the value most recently determined in step S501 or S506.

  Then, the block enlargement / reduction unit 120A determines whether or not the output block image size associated with each processing number p exceeds the upper limit of the block image size that can be output in each block image processing unit (S504). If it is determined that the number has exceeded, the operation starts from step S505, which will be described later. Otherwise, the operation starts from step S506, which will be described later.

  When the output block image size related to the process number p exceeds the above upper limit, the block enlargement / reduction unit 120A changes the output block image size in the last stage (for example, one pixel at a time in width and height). After changing to a smaller size (S506), the operation returns to step S502 described above.

  Then, the block enlargement / reduction unit 120A determines whether or not the calculation of the output block image size is completed for all the process numbers when the output block image size related to the process number p does not exceed the above-described upper limit. (It is determined whether p is 0) (S505).

  The block enlargement / reduction unit 120A ends the process when the calculation of the output block image size is completed for all the process numbers, and decrements (subtracts 1) from p otherwise (S507). The operation starts from step S503.

  As described above, the block enlargement / reduction unit 120A calculates the size of the output block image of each block image processing unit in the enlargement / reduction processing unit 100A in order from the last processing unit, and restricts all the processing units. The loop process of the flowchart of FIG.

  Based on the restriction of FIG. 11, the block enlargement / reduction unit 120A performs the process of the flowchart of FIG. 12 and calculates the size of the output block image of each block image processing unit. It becomes the contents like.

  In step S203, the block enlargement / reduction unit 120A determines the number of divisions of the block image with respect to the image G101 based on the size of the input block image calculated in step S202 described above, by the same processing as in the first embodiment. calculate.

  In this example, as described above, the size of the input image G101 is the width 7680 and the height 5120. Therefore, when the set magnification is 133%, the width and height of the input block image are 194, so the number of divisions in the X direction is 40 and the number of divisions in the Y direction is 27. When the set magnification is 41%, the width and height of the input block image are 626, so the number of divisions in the X direction is 13, and the number of divisions in the Y direction is 9.

  In step S204, the block enlargement / reduction unit 120A sets the initial values of the X direction enlargement / reduction counter 121a and the Y direction enlargement / reduction counter 122a and the block image read by the block reading unit 110 for each block image. The reading positions in the X direction and the Y direction are calculated. The processing in step S204 by the block enlargement / reduction unit 120A is substantially the same as that in the first embodiment, except that the pre-filter processing unit 140 and the post-filter processing unit 150 are inserted into the enlargement / reduction processing unit 100A. It is necessary to obtain each value in consideration.

In the second embodiment, the initial value of the Y direction enlargement / reduction counter 122a, the initial value of the Y direction enlargement / reduction counter 122a, the readout position in the X direction, and the readout position in the Y direction are respectively (28) to (28) 31).

  In the following equations (28) to (31), bnulw and bnullh represent the number of invalid pixels generated at the left end and the upper end of the block image in the process of the block enlargement / reduction unit 120A. Anulw and anulh represent the number of invalid pixels generated at the left end and the upper end of the block image in the subsequent processing of the block enlargement / reduction unit 120A.

[Calculation formula for enlargement / reduction counter in X direction]
xcnt0 [0] = (xratio− (anulw × xbase)% xratio)% xratio (28)
[Calculation formula for enlargement / reduction counter in Y direction]
ycnt0 [0] = (yratio− (anulh × ybase)% yratio)% yratio (29)
[Reading position in X direction]
xpos0 [0] = − (anulw × xbase + xratio−1)
/ Xratio-bulw (30)
[Reading position in Y direction]
ypos0 [0] = − (anulh × ybase + yratio−1)
/ Yratio-bnull (31)
By operating the enlargement / reduction processing unit 100A using the parameters calculated in S201 to S204 described above, image data of one page is divided into a plurality of blocks, and enlargement / reduction at an arbitrary magnification and front and rear filters are performed. Processing can be performed.

(B-2-3) Input Block Image Reading Process by Block Reading Unit 110A Next, details of the input block reading process performed by the block reading unit 110A in the above-described step S403 will be described with reference to FIG. .

  FIG. 14 is an explanatory diagram showing processing when the block reading unit 110A reads the image G101 input to the enlargement / reduction processing unit 100A in units of input blocks according to the parameters determined in step S403 described above. In FIG. 14, the size of the input image G101 is shown for a case where the width is 7680, the height is 5120, and the set magnification is 133%.

  As illustrated in FIG. 14, the block image read by the block reading unit 110 </ b> A is read so as to have an overlapping portion with an adjacent block. In FIG. 14, the position in the X direction of the leftmost pixel of one page of image data to be read is 0, and the position in the Y direction of the uppermost pixel is 0. Then, the reading start position in the X direction and the Y direction of the block image to be divided by the block reading unit 110A is the block numbers 0, 1, 2, 3, 4,. -15, 178, 370, 563, 755,..., And the reading start position in the Y direction corresponds to block numbers 0, 1,. It becomes. For example, if the block number in the X direction is 2 and the block number in the Y direction is 1, the read positions in the X direction and the Y direction are (370, 178). In FIG. 14, the size of each block image read by the block reading unit 110A is common to all block images (in the example, width 222 × height 222). As shown in FIG. 14, the block reading unit 110A needs to read a block image read in the vicinity of the outer periphery of the page from an area outside the page, and the data in the area outside the page is white data ( (White pixel value) or may be replaced using a pixel located at the boundary with the outside of the page.

  Then, the block readout unit 110A reads out each block image while changing the readout position in the X direction and the Y direction according to the block number in the X direction and the Y direction of each block image, and performs the pre-filter processing on the read block image To the unit 140.

(B-2-4) Enlargement / Reduction Process by Block Enlargement / Reduction Unit 120A Next, details of the process performed by the block enlargement / reduction unit 120A in step S403 will be described.

  FIG. 15 is an explanatory diagram showing an example of processing for each block image performed by the block enlargement / reduction unit 120A. In FIG. 15, the size of the input image G101 is shown for the case where the width is 7680, the height is 5120, and the set magnification is 133%.

  The block image (see FIG. 15A, the block image size is width 222 × height 222) input to the pre-filter processing unit 140 is 25 × 25 pixels centered on the target pixel in the pre-filter processing unit 140. The filtering process for performing the reference is performed, and the filtered image is supplied to the block enlargement / reduction unit 120A.

  The block image processed by the pre-filter processing unit 140 by the filter process by the pre-filter processing unit 140 generates 12 invalid pixels at the left end, right end, upper end, and lower end as shown in FIG. 15B.

  The block image input to the block enlargement / reduction unit 120A is subjected to enlargement processing by the enlargement / reduction unit, and the enlarged block image is supplied to the post-filter processing unit 150.

  The block image (width 222 × height 222) input to the block enlargement / reduction unit 120A is first enlarged in the X direction by the X direction enlargement / reduction unit 121A (see FIG. 15C, the block image size is the width). 262 × height 222), and further, the Y-direction enlargement / reduction unit 122A enlarges and outputs the Y-direction (see FIG. 15D, the block image size is width 262 × height 262).

  In the X-direction enlargement by the X-direction enlargement / reduction unit 121A, the X-direction enlargement / reduction counter 121a is set to the initial value corresponding to the X-direction block number of the block image at the head of each block line. For example, if the block number in the X direction is 2, it is set to 94. After the input pixels are ignored until the X-direction skip counter 121c, which starts counting from the left end of the block, reaches a predetermined value (12 in the example) (the 12 invalid pixels at the left end of the block generated in the previous stage processing are Are deleted), line-by-line enlargement is performed according to the X-direction enlargement / reduction counter 121a, and the X-direction output counter 121b is enlarged and output until it reaches a predetermined value (262 in the example) (see FIG. 15E). The 12 invalid pixels and extra pixels at the right end of the block generated in the previous stage processing are deleted by the above operation).

  In the Y-direction enlargement by the Y-direction enlargement / reduction unit 122A, the Y-direction enlargement / reduction counter 122a is set to the initial value corresponding to the block number in the Y direction of the block image at the head line of each block. For example, if the block number in the Y direction is 1, it is set to 30. After the input pixels are ignored until the Y-direction skip counter 122c, which starts counting from the upper end of the block, reaches a predetermined value (12 in the example) (the 12 invalid pixels at the upper end of the block generated in the previous processing are Is deleted), the enlargement is performed according to the Y-direction enlargement / reduction counter 122a, and the Y-direction output counter 122b is enlarged and output until it reaches a predetermined value (262 in the example) (see FIG. 15 (f), The 12 invalid pixels at the bottom of the block and the extra pixels generated in the previous process are deleted by the above operation).

  As described above, the block enlargement / reduction unit 120A enlarges the input block image, deletes the invalid pixels at the end of the block image generated by the filter processing of the previous-stage filter processing unit 140, and each block image Output with the same size. The output block image is supplied to the post-filter processing unit 150.

(B-2-5) Processing of Post Filter Processing Unit 150 and Block Cut Processing Unit 160 Details of processing performed by the post filter processing unit 150 and the block cut processing unit 160 in step S403 described above will be described below.

  FIG. 16 is an explanatory diagram showing an example of processing for each block image performed by the post-filter processing unit 150 and the block cut processing unit 160.

  The block image (refer to FIG. 16A, the block image size is width 262 × height 262) input to the post-filter processing unit 150 is a 7 × 7 pixel reference centered on the target pixel in the post-filter processing unit 150. A filtering process is performed. Then, the image that has been post-filtered by the post-filter processing unit 150 is supplied to the block cut processing unit 160. As a result of post-filter processing by the post-filter processing unit 150, three invalid pixels are generated at the left end, right end, upper end, and lower end of the processed block image, as shown in FIG. 16B.

  The block image (the size of the block image is width 262 × height 262) input to the block cut processing unit 160 is an invalid pixel (in the example, the left end in the example) at the end of the block image generated by the previous process in the block cut processing unit 160. A block image (see FIG. 16C; the size is width 256 × height 256) from which invalid pixels are cut is supplied to the block writing unit 130A. The

(B-2-6) Write processing by block writing unit 130A The block writing unit 130A performs a process similar to that of the first embodiment to distribute the supplied block images at constant intervals in the X and Y directions (about the X direction). Is written to the image memory 60 in 256 for the Y direction, and data for the image G104 for one page is created.

(B-3) Effects of Second Embodiment According to the second embodiment, the following effects can be obtained in addition to the effects of the first embodiment.

  In the second embodiment, the pre-filter process and the post-filter process are also processed in block image units by the block enlargement / reduction unit 120A. Therefore, in the image forming apparatus 1 of the first embodiment, as shown in FIG. 1, four image data (G101 to G104) are processed in the image memory 60 until the image data is input and output ( However, in the image forming apparatus 1A of the second embodiment, the processing is completed only by processing the two image data (G101, G104) as shown in FIG.

  Therefore, in the image forming apparatus 1A according to the second embodiment, the access amount to the image memory 60 can be reduced and the processing speed can be increased as compared with the first embodiment. Further, in the image forming apparatus 1A according to the second embodiment, it is possible to reduce the capacity required for the image memory 60.

(C) Third Embodiment Hereinafter, an image processing apparatus and method and an image forming apparatus according to a third embodiment of the present invention will be described in detail with reference to the drawings.

(C-1) Configuration of Third Embodiment FIG. 17 is a schematic diagram showing a configuration of an image forming apparatus according to the third embodiment of the present invention, and the same or corresponding parts as those in FIG. Corresponding symbols are attached.

  Hereinafter, differences of the third embodiment from the second embodiment will be described.

  The third embodiment is different from the second embodiment in that the enlargement / reduction processing unit 100A is replaced with an enlargement / reduction processing unit 100B. In the enlargement / reduction processing unit 100B of the third embodiment, the block enlargement / reduction unit 120A is replaced with the block enlargement / reduction unit 120B, and further, the front resolution conversion unit 170, the rear resolution conversion unit 180, and the quantization process This is different from the second embodiment in that a part 190 is added. In the block enlargement / reduction unit 120B of the third embodiment, the X direction enlargement / reduction unit 121A and the Y direction enlargement / reduction unit 122A are replaced with the X direction enlargement / reduction unit 121B and the Y direction enlargement / reduction unit 122B. This is different from the second embodiment.

  In the enlargement / reduction processing unit 100B, a previous resolution conversion unit 170 is inserted between the block reading unit 110A and the previous filter processing unit 140 (position before the block enlargement / reduction unit 120B). Further, in the enlargement / reduction processing unit 100B, a post-resolution conversion unit 180 is inserted between the post-filter processing unit 150 and the block cut processing unit 160 (position after the block enlargement / reduction unit 120B). Further, in the enlargement / reduction processing unit 100B, a quantization processing unit 190 is inserted between the block cut processing unit 160 and the block writing unit 130A (position after the block enlargement / reduction unit 120B).

  When the pre-filter processing unit 140 according to the first embodiment or the second embodiment wants to perform processing on image data having a specific resolution, resolution conversion processing (multiplication resolution conversion or one-multiplication resolution conversion) ) Must be performed before pre-filter processing (for example, by making the same vertical and horizontal resolution of image data, it is possible to make the same processing in the vertical and horizontal directions for the filter processing that suppresses screen determination and moire generation of the document. And the configuration is simplified). If the resolution of the image data after processing by the post-filter processing unit 150 and the number of bits per pixel are different from the resolution expected by the image output unit 50 and the number of bits per pixel, resolution conversion (multiplication) is performed after the post-filter processing. Resolution conversion) and quantization processing. When the resolution conversion and the quantization processing are performed, image data is read from or written to the image memory, and the required size of the image memory increases and the processing speed is reduced. Therefore, in the third embodiment, the pre-filter processing unit 140 is inserted before the block enlargement / reduction unit 120B and the pre-filter processing unit 140, and only the block image of the size to be output and the ratio of the cut-out block image are obtained. The resolution is converted. In the third embodiment, the post-resolution conversion unit 180 is inserted after the block enlargement / reduction unit 120B and the post-filter processing unit 150 to output the block image output from the block enlargement / reduction unit 120B. The resolution is converted to a size image.

  The pre-resolution conversion unit 170 performs resolution conversion (multiplication resolution conversion or 1 / multiplication resolution conversion) of block image data input from the block reading unit 110A. For example, the pre-resolution conversion unit 170 converts the input block image data having a resolution of 300 DPI × 600 DPI into image data having a resolution of 600 DPI × 600 DPI. Then, the block image data whose resolution is converted is supplied to the pre-filter processing unit 140.

  The X direction enlargement / reduction unit 121B and the Y direction enlargement / reduction unit 122B of the block enlargement / reduction unit 120B finely adjust the skip width for each image block in the X direction and the Y direction in accordance with the addition of the previous resolution conversion unit 170. Unlike the second embodiment, the skip width finely adjusted by the value (hereinafter referred to as “fine adjustment skip value”) is set in the skip counter (X direction skip counter 121c, Y direction skip counter 122c). Yes.

  In other words, the block enlargement / reduction unit 120B (the X direction enlargement / reduction unit 121B and the Y direction enlargement / reduction unit 122B) skips the pixels at the left end and the upper end of the input block image, as in the second embodiment. The counter ignores the pixels in the predetermined value range, enlarges / reduces only the remaining pixels according to the enlargement / reduction counter, and operates so as to output only when the output counter is within the predetermined value range. However, the block enlargement / reduction unit 120B adds a fine adjustment skip value for each block in the X direction and the Y direction to a predetermined value common to all image blocks in the range of the predetermined value that is ignored by the skip counter value. It is assumed that a process of ignoring (skip) the range of the value (hereinafter, this fine adjustment process is also referred to as “skip value fine adjustment process”). In other words, in the block enlargement / reduction unit 120B, the value set in the skip counter is variable for each block (a value finely adjusted (corrected) with respect to a common predetermined value is set).

  FIG. 18 is an explanatory diagram showing an example of the operation of the X direction enlargement / reduction unit 121B. In FIG. 18, the X-direction readout position of the block image input to the block enlargement / reduction unit 120B and the X Describe the skip range of the direction.

  18 (a) to 18 (c) show X images for different image blocks (block images whose read positions in the X direction are -14, 178, and 371 (X direction 0, first, and second block images)). It is explanatory drawing shown about the case where the direction expansion / reduction part 121B sets the reading position of a X direction, without performing a skip value fine adjustment process (process when the process similar to 2nd Embodiment is performed). . 18D to 18F show the image blocks similar to those in FIGS. 18A to 18C after the X-direction enlargement / reduction unit 121B performs the skip value fine adjustment processing. FIG. 6 is an explanatory diagram showing a case where a reading position in the X direction is set.

  As shown in FIGS. 18A to 18C, X-direction enlargement / reduction of block images (X direction 0, 1st, and 2nd block images) whose read positions in the X direction are −14, 178, and 371 are performed. In the case where enlargement / reduction is performed by ignoring the leftmost 12 pixels in the unit 121B, the range of a predetermined value ignored by the X-direction skip counter 121c may be set to 12 when there is no previous resolution conversion.

  However, when the same processing as described above is performed with the previous resolution conversion unit 170 converting the resolution in the X direction to twice, it is only necessary to read from the position where the read position when there is no previous resolution conversion is halved. However, since reading is not possible from a position that does not become an integer (when the reading position 371 of the second block is halved to 185.5), reading is performed from reading positions −7, 89, and 185 in the X direction. Therefore, for the 0th and 1st block images, as in the case where there is no previous resolution conversion, the range of the predetermined value to be ignored by the skip counter may be set to 12, but the 2nd block image Since the reading position converted by the unit 120B is shifted by 1, it is necessary to set the range of the predetermined value ignored by the skip counter to 13. By setting the amount of deviation from the predetermined value as a fine adjustment skip value for each block in the X direction and the Y direction, it is possible to cope with resolution conversion by the previous resolution conversion unit 170.

  The post-resolution conversion unit 180 performs resolution conversion (multiplication resolution conversion) of the image data input from the post-filter processing unit 150. For example, the post-resolution conversion unit 180 converts the input image data having a resolution of horizontal 600 DPI × vertical 600 DPI into horizontal. The image data is converted to image data having a resolution of 600 DPI × 1200 DPI. The post-resolution conversion unit 180 supplies the block image whose resolution has been converted to the block cut processing unit 160.

  The quantization processing unit 190 performs quantization processing on the block image supplied from the block cut processing unit 160. For example, an 8-bit block image per pixel supplied to the quantization processing unit 190 may be quantized to 1-bit image data per pixel by comparing with a preset threshold value or the like. The image data quantized to 1 bit is collected into 8 bit data in units of 8 pixels and supplied to the block writing unit 130A. For example, when the image output unit 50 is an electrophotographic printer or the like, the image processing apparatus 1 includes the quantization processing unit 190 and generates image data for each color of the developer (toner agent). Can do.

(C-2) Operation of Third Embodiment Next, the operation (image processing method of the embodiment) of the image forming apparatus 1B of the third embodiment having the above-described configuration will be described. Hereinafter, the operation of the image forming apparatus 1B according to the third embodiment will be described focusing on the difference from the operation according to the second embodiment.

(C-2-1) Overview of Overall Operation of Image Forming Apparatus 1B FIG. 19 is a flowchart showing the overall operation of image forming apparatus 1B.

  First, in the image forming apparatus 1A, it is assumed that the data of the image G101 is input to the image input unit 10 and is written in the image memory 60 as the image G101. Then, it is assumed that the set magnification is set in the enlargement / reduction processing unit 100B (S501).

  Here, it is assumed that the image G101 is an image having a width of 7680 pixels and a height of 5120 pixels. Here, the case where 133% is set as the set magnification in the enlargement / reduction processing unit 100B and the case where 41% is set will be described separately.

  Next, the enlargement / reduction processing unit 100B prepares for calculation of each parameter related to enlargement / reduction based on the size of the image G101 to be enlarged / reduced and the set magnification (S502).

  Next, each processing unit of the enlargement / reduction processing unit 100B performs read processing, pre-filter processing, pre-resolution conversion processing, enlargement / reduction processing, post-filter processing, post-resolution conversion processing, block cut processing, quantum cut processing in units of blocks. Processing and writing processing are performed, and the processed image data G104 is written in the image memory 60 (S503).

  Then, the processed image data G104 is output by the image output unit 50 (S504).

(C-2-2) Parameter calculation for enlargement / reduction (step S502)
Next, with respect to a method for calculating parameters necessary for the enlargement / reduction unit 300 of the third embodiment, image data (width 300 DPI × height 600 DPI) having a width of 3840 pixels and a height of 5120 pixels is enlarged at a magnification of 133%. A case where reduction is performed at a magnification of 41% is described as an example.

  Further, the pre-filter processing unit 140 performs a filter process for referring to a 25 × 25 pixel around the target pixel, and the post-filter processing unit 150 performs a filter process for referring to a 5 × 5 pixel around the target pixel. The pre-resolution conversion unit 170 performs processing for doubling the X-direction resolution, the post-resolution conversion unit 180 performs processing for doubling the Y-direction resolution, and the quantization processing unit 190 performs per-pixel processing. It is assumed that a process of converting 8-bit image data into 1-bit image data per pixel is performed.

  Further, the pre-filter processing unit 140, the block enlargement / reduction unit 120B, the post-filter processing unit 150, and the post-resolution conversion processing unit 330 include line memories that hold images of 288, 264, 262, and 262 pixels, respectively. The block width that can be output in each processing unit is assumed to have the above value as the upper limit.

  The overall processing of the parameter calculation method necessary for each part of the enlargement / reduction processing unit 100B will be described with reference to the flowchart of FIG.

  First, in step S601, the block enlargement / reduction unit 120B calculates the size (width and height of the output image of one page) of the image data G104 output after the enlargement / reduction processing based on the image G101 and the set magnification. .

  In the block enlargement / reduction unit 120B of the third embodiment, in addition to the size change due to enlargement / reduction, the size change due to each processing unit of the pre-resolution conversion unit 170, the post-resolution conversion unit 180, and the quantization processing unit 190 is considered. There is a need. In the following description, the ratio between the input image width in the X direction and the output image width (the number of BYTEs) of each processing unit described above is xbase, xratio, and the ratio between the input image height in the Y direction and the output image height is ybase, yratio. explain. In the following description, it is assumed that the parameters (xbase, xratio, ybase, yratio) relating to each of the above-described processing units are as shown in the table of FIG.

  Therefore, in the block enlargement / reduction unit 120B, for each of the above parameters (xbase, xratio, ybase, yratio), the parameter of each of the above processing units is raised to the power, and the denominator (hereinafter, “Xbase_t”) and numerator (hereinafter referred to as “xratio_t”), Y direction magnification denominator (hereinafter referred to as “ybase_t”) and numerator (hereinafter referred to as “xratio_y”) are obtained. Then, the block enlargement / reduction unit 120B calculates the size (width and height of the output image of one page) of the image data G104 output after the enlargement / reduction processing using the following equations (32) and (33). To do.

  In the following equations (32) and (33), XO is the number of pixels in the width (X direction) of the output image data G104. XI is the number of pixels in the width (X direction) of the image G101 to be processed. Furthermore, YO is the number of pixels in the height (Y direction) of the output image data G104. Furthermore, YI is the number of pixels in the height (Y direction) of the image G101 to be processed.

XO = (XI) × (xratio_s) / (xbase_s) (32)
YO = (YI) × (yratio_s) / (ybase_s) (33)
In the example of enlarging the input image G101 (width 3840, height 5120) to 133%, the output image width XO is 3840 × (2 × 133 × 1 × 1) / (1 × 100 × 1 × 8). = 1276, and the output image height YO is 5120 × (1 × 133 × 2 × 1) / (1 × 100 × 1 × 1) = 13619. In the example of reduction to 41%, the output image width XO is 3840 × (2 × 41 × 1 × 1) / (1 × 100 × 1 × 8) = 393, and the output image height YO is 5120 × ( 1 × 41 × 2 × 1) / (1 × 100 × 1 × 1) = 4198.

  In step S602, the block enlargement / reduction unit 120B calculates an input block cumulative invalid size. The input block cumulative invalid size is the size of invalid pixels included in the block image input to each processing unit. In each processing unit, the size of invalid pixels generated in the processing unit upstream (previous stage) of each processing unit. It is obtained by accumulating. Further, in each processing unit, when the processing unit in the previous stage performs the resolution conversion, it is necessary to consider the content of the resolution conversion. Furthermore, in each processing unit, when the preceding processing unit is the block enlargement / reduction unit 120B or the block cut processing unit 160, the invalid pixels accumulated in the processing unit are deleted and thus become 0. Accordingly, the cumulative invalid size of each processing unit can be calculated by calculating in order from the upstream block reading unit 110A using the following equation.

  Therefore, in the block enlargement / reduction unit 120B, when “the previous processing unit is the block enlargement / reduction unit 120B or the block cut processing unit 160”, the accumulated invalid sizes of the left end, the right end, the upper end, and the lower end are set as follows. It can obtain | require by the following (34) Formula-(37) Formula.

  In the following equations (34) to (37), ulwL, ulwR, ulhU, and ulhD are sizes of invalid pixels generated in each processing unit (see the table in FIG. 21). In the operation example of the third embodiment (example according to the table of FIG. 21), the cumulative invalid size of the left end / right end / upper end / lower end of each processing unit is 0/0 by the block reading unit 110A and the previous resolution conversion unit 170. / 0/0, 0/1/0/0 in the pre-filter processing unit 140, 12/13/12/12 in the block enlargement / reduction unit 120B, 0/0/0/0 in the post-filter processing unit 150, and post-resolution conversion 2/2/2/2 in the unit 180, 2/4/4 in the block cut processing unit 160, and 0/0/0/0 in the quantization processing unit 190 and the block writing unit 130A. Note that the range of the left end and top end values of the cumulative invalid size is a range that is ignored at the left end and top end of the block image in the block enlargement / reduction unit 120B (except for the portion ignored by the fine adjustment skip value).

[When the pre-stage processing unit is other than the block enlargement / reduction unit 120B or the block cut processing unit 160]
(Leftmost cumulative invalid size) =
((Left end cumulative invalid size of the pre-processing unit) x (x ratio of the pre-processing unit)
+ (Xbase of the pre-processing unit) -1) / (xbase of the pre-processing unit)
+ (NullwL of the pre-processing unit) (34)
(Right-end cumulative invalid size) =
((Right-end cumulative invalid size of pre-processing unit) x (x-ratio of pre-processing unit)
+ (Xbase of the pre-processing unit) -1) / (xbase of the pre-processing unit)
+ (NullwR of the pre-processing unit) (35)
(Upper end cumulative invalid size) =
((Upper end cumulative invalid size of previous processing unit) × (yatio of previous processing unit)
+ (Ybase of pre-processing unit) -1) / (ybase of pre-processing unit)
+ (NullU of the pre-processing unit) (36)
(Bottom bottom invalid size) =
((Lower-end cumulative invalid size of the pre-processing unit) × (yatio of the pre-processing unit)
+ (Ybase of pre-processing unit) -1) / (ybase of pre-processing unit)
+ (NullhD of the pre-processing unit) (37)
As described above, when the preceding processing unit is the block enlargement / reduction unit 120B or the block cut processing unit 160, the invalid pixels accumulated by the processing unit are deleted and become 0, so the left edge, The cumulative invalid sizes at the right end, the upper end, and the lower end are expressed by the following equations (38) to (41), respectively.

[When the pre-processing unit is the block enlargement / reduction unit 120B or block cut processing unit 160]
(Left end cumulative invalid size) = 0 (38)
(Right-end cumulative invalid size) = 0 (39)
(Upper end cumulative invalid size) = 0 (40)
(Lower end cumulative invalid size) = 0 (41)
In step S603, the enlargement / reduction processing unit 100B calculates the input / output block image size of each processing unit. The enlargement / reduction processing unit 100B determines the output block image size in each processing unit by the processing substantially the same as that of the second embodiment (step S202 in FIG. 4 and the flowchart in FIG. 12). The output block image size in each processing unit is calculated by repeatedly calculating until the output block image size in each processing unit is within the limit in all processing units. In addition, in the enlargement / reduction processing unit 100B of the third embodiment, the calculation related to the output block image in each processing unit is performed by adding the pre-resolution conversion unit 170, the post-resolution conversion unit 180, and the quantization processing unit 190. Since it is necessary to change the processing, the difference will be mainly described below.

  When the output block image size for each processing number (each block image processing unit) in the third embodiment is calculated according to the flowchart of FIG. 12 described above, it can be obtained by the following equations (42) to (47).

  In the following equations (42) to (47), inc_nullL / R [p] and inc_nullU / D [p] are the cumulative values of the left end / right end / upper end / lower end of each processing unit obtained in step S602 described above. Invalid size. Also, outbw [p] and outbh [p] are the width and height of the block image output by each processing unit, as in the second embodiment.

  The output block size of the block writing unit 130A can be set to an arbitrary value as in the following expressions (42) and (43).

outbw [p] = arbitrary value (42)
outbh [p] = arbitrary value (43)
The output block sizes of the post filter processing unit 150 and the pre filter processing unit 140 can be obtained by the following formulas (44) and (45).

outbw [p] = (outbw [p + 1] × xbase [p + 1]
+ Xratio [p + 1] -1) / xratio [p + 1]
+ Inc_nullL [p + 1] + inc_nullR [p + 1]
+ NulwL [p + 1] + nulwR [p + 1] (44)
outbh [p] = (outbh [p + 1] × ybase [p + 1]
+ Yratio [p + 1] -1) / yratio [p + 1]
+ Inc_nullU [p + 1] + inc_nullhD [p + 1]
+ Nullh [p + 1] + nullh [p + 1] (45)
The output block sizes of the quantization processing unit 190, the block cut processing unit 160, the post filter processing unit 150, the block enlargement / reduction unit 120B, the pre-resolution conversion unit 170, and the block reading unit 110A are the following equations (46) and (47). It can be obtained by an expression.

outbw [p] = (outbw [p + 1] × xbase [p + 1]
+ Xratio [p + 1] -1) / xratio [p + 1] (46)
outbh [p] = (outbh [p + 1] × ybase [p + 1]
+ Yratio [p + 1] -1) / yratio [p + 1] (47)
With the processing as described above, the output block image size of each processing unit calculated by the enlargement / reduction processing unit 100B is, for example, as shown in FIG.

  In step S604, the block enlargement / reduction unit 120B calculates the number of divisions in the X direction and the Y direction (similar to the first embodiment). In the third embodiment, in the example of enlargement to 133%, the number of divisions in the X direction is 40, the number of divisions in the Y direction is 54, and in the example of reduction to 41%, the number of divisions in the X direction is 33, the number of divisions in the Y direction is 17.

  In step S605, the enlargement / reduction processing unit 100B calculates a stride value for each processing unit. The stride value is a portion of block image data input to each processing unit of the enlargement / reduction processing unit 100B that is output without overlapping with an adjacent block (an effective portion that is finally written by the block writing unit 130A). Width and height. The enlargement / reduction processing unit 100B can obtain the stride value in each processing unit using, for example, the following equations (48) to (51) using the block image size output by the block writing unit 130A. .

  In the following formulas (48) to (51), xstride [p] and ystride [p] are the stride values in the X direction and Y direction of each processing unit, respectively.

  The stride value of the block writing unit 130A can be obtained using the following equations (48) and (49).

xstride [p] = (output block width) (48)
ystride [p] = (output block width) (49)
The stride value of the block writing unit 130A can be obtained using the following equations (48) and (49).

  The stride value of each processing unit other than the block writing unit 130A constituting the enlargement / reduction processing unit 100B can be obtained using the following equations (50) and (51).

xstride [p] = (xstride [p + 1] × xbase [p]
+ Xratio [p] -1) / xratio [p] (50)
ystride [p] = (ystride [p + 1] × ybase [p]
+ Yratio [p] -1) / yratio [p] (51)
Hereinafter, the stride values in the X direction and the Y direction of each processing unit will be described separately for the case where the enlargement / reduction processing unit 100B enlarges to 133% and the case where the enlargement / reduction processing unit 100B reduces to 41%.

  First, an example of the stride value (xstride) in the X direction and the stride value (ystride) in the Y direction of each processing unit when the enlargement / reduction processing unit 100B enlarges to 133% will be described. In this case, in the block writing unit 130A and the quantization processing unit 190, xstride = 32 and ystride = 256. In this case, the block cut processing unit 160 has xstride = 256 and ystride = 256. Further, in this case, in the post-resolution conversion unit 180 and the post-filter processing unit 150, xstride = 256 and ystride = 128. Furthermore, in the block enlargement / reduction unit 120B and the pre-filter processing unit 140, xstride = 193 and ystride = 97. In the previous resolution conversion unit 170 and the block reading unit 110A, xstride = 97 and ystride = 97.

  Next, an example of the stride value (xstride) in the X direction and the stride value (ystride) in the Y direction of each processing unit when the enlargement / reduction processing unit 100B reduces to 41% will be described. In this case, in the block writing unit 130A and the quantization processing unit 190, xstride = 12, ystride = 256. In this case, in the block cut processing unit 160, xstride = 96 and ystride = 256. Further, in this case, in the post-resolution conversion unit 180 and the post-filter processing unit 150, xstride = 96 and ystride = 128. Furthermore, in this case, in the block enlargement / reduction unit 120B and the pre-filter processing unit 140, xstride = 235 and ystride = 313. In this case, in the previous resolution converting unit 170 and the block reading unit 110A, xstride = 118 and ystride = 313.

  Next, in step S606, the enlargement / reduction processing unit 100B sets the initial values of the enlargement / reduction counters in the X and Y directions for each block image, and the read positions in the X and Y directions of each block image read by the block reading unit 110A. The fine adjustment skip values in the X direction and the Y direction for each block image are calculated. The enlargement / reduction processing unit 100B can calculate the above-described values using, for example, the following equations (52) to (65).

  In the following formulas (52) to (65), xno and yno represent the block number in the X direction and the block number in the Y direction, and xcnt [] and ycnt [] are initial values of the enlargement / reduction counter in the X direction. Represents the value and the enlargement / reduction counter in the Y direction. Further, xpos0 [] and ypos0 [] represent a reading position in the X direction and a reading position in the Y direction. Furthermore, modw [] and mod [] represent the fine adjustment skip value in the X direction and the fine adjustment skip value in the Y direction. Furthermore, x stride and y stirde represent the stride value of the subsequent processing unit of the block enlargement / reduction unit 120B. Further, xbase and xratio represent the denominator and numerator of the X magnification of the block enlargement / reduction unit 120B, and ybase and yratio represent the denominator and numerator of the Y magnification of the block enlargement / reduction unit 120B. Further, bnulw and bnulh are the width and height of the left and top invalid pixels included in the block image input to the block enlargement / reduction unit 120B (the same as the leftmost cumulative invalid size and the top cumulative invalid size). Furthermore, anulw and anulh represent the number of invalid pixels generated in the block image in the subsequent processing of the block enlargement / reduction unit 120B.

  The enlargement / reduction processing unit 100B can obtain the initial value of the enlargement / reduction counter in the X direction for each block image using, for example, the following equations (52) and (53).

xcnt0 [0] = (xratio− (anulw × xbase)
% Xratio)% xratio (52)
xcnt0 [xno] = (xstride × xbase + xcnt0 [xno−1])
% Xratio (53)
The enlargement / reduction processing unit 100B can obtain the initial value of the enlargement / reduction counter in the X direction for each block image using, for example, the following expressions (54) and (55).

ycnt0 [0] = (yratio− (anulh × ybase)
% Yratio)% yratio (54)
ycnt0 [yno] = (ystride × ybase + ycnt0 [yno−1])
% Yratio (55)
The enlargement / reduction processing unit 100B can obtain the reading position in the X direction of each block image read by the block reading unit 110A using, for example, the following equations (56) to (57): xpos0 ′ [0] = − (Anulw × xbase + xratio−1)
/ Xratio-bulw (56)
xpos0 '[xno] = xpos0' [xno-1]
+ (Xstride × xbase + xcnt0 [xno−1])
/ Xratio (57)
xpos0 [xno] = (xpos0 ′ [xno]
X (xbase of previous resolution conversion unit 170))
/ (Xratio of the previous resolution converter 170) (58)
The enlargement / reduction processing unit 100B can obtain the reading position in the X direction of each block image read by the block reading unit 110A using, for example, the following equations (59) to (61).

ypos0 ′ [0] = − (anulh × ybase + yratio−1)
/ Yratio-bullh (59)
ypos0 '[yno] = ypos0' [yno-1]
+ (Ystride × ybase + ycnt0O [yno-1])
/ Yratio (60)
ypos0 [yno] = (ypos0 ′ [yno]
X (ybase of previous resolution conversion unit 170))
/ (Yatio of the previous resolution converter 170) (61)
The enlargement / reduction processing unit 100B can obtain the fine adjustment skip value in the X direction using, for example, the following equations (62) and (63).

modw [0] = ((anulw × xbase + xratio−1)
/ Xratio)% (xratio of the previous resolution conversion unit 170)
modw [xno] = (modw [xno-1] (62)
+ (Xstride × xbase + xcnt0 [xno−1])
/ Xratio)% (ratio of the previous resolution conversion unit 170x) (63)
The enlargement / reduction processing unit 100B can obtain the fine adjustment skip value in the Y direction using, for example, the following equations (64) and (65).

mod [0] = ((anulh × ybase + yratio−1)
/ Yratio)% (yratio of the previous resolution conversion unit 170)
mod [yno] = (modh [yno-1] (64)
+ (Ystride × ybase + ycnt0 [yno−1])
/ Yratio)% (yratio of the previous resolution conversion unit 170) (65)
As described above, in the block enlargement / reduction unit 120B, using the above formula, in the same manner as in the first and second embodiments, the block is sequentially from the leftmost block in the X direction and the upper end in the Y direction. Each of the above values is calculated in order from the block.

  The image processing apparatus 1 operates the enlargement / reduction processing unit 100B using the parameters calculated in steps S601 to S606 described above, thereby dividing one page of image data into a plurality of blocks and having an arbitrary magnification. Enlargement / reduction, front / rear filter processing, front / rear resolution conversion processing, and quantization processing can be performed.

  Next, a specific operation (an example in the case of enlarging to 133%) using each parameter calculated by the above-described steps S601 to S606 will be described.

  First, the operation of the block reading unit 110A will be described with reference to FIG.

  FIG. 23 shows a block image obtained by dividing the image of one page stored in the image memory 60 into the X direction and the Y direction by the block reading unit 110A when the enlargement / reduction processing unit 100B executes 133% enlargement processing. It is a specific example of the operation | movement read out as.

  As shown in FIG. 23, as shown in FIG. 23, the block image read out by the block reading unit 110A is read so as to have an overlapping portion with an adjacent block. When the position of the leftmost pixel in the image data of one page to be read is set to 0 and the position of the uppermost pixel in the Y direction is set to 0 in the block reading unit 110A, the X and Y directions of the divided block image are set to 0. The read start position corresponds to block numbers 0, 1, 2, 3, 4,... In the X direction for the read start position in the X direction, and is −7, 89, 185, 281, 378,. The read start position in the Y direction is −14, 82 corresponding to the block numbers 0, 1,. For example, if the block number in the X direction is 2 and the block number in the Y direction is 1, the read positions in the X direction and the Y direction are (185, 82). In addition, the size of each block image to be read is common to all the block images (in the example, horizontal 112 × vertical 125). It should be noted that the block image read out near the outer periphery of the page needs to be read out from the area outside the page, and the data in the area outside the page is replaced with white data (dummy data) or the boundary with the outside of the page Replace with the pixel located at.

  The block readout unit 110A reads out each block image while changing the readout position in the X direction and the Y direction in accordance with the block numbers in the X direction and the Y direction of each block image, and reads the read block image into the pre-resolution conversion unit 170. To supply.

  The block image (the size of the block image is horizontal 112 × vertical 125) input to the pre-resolution converter 170 is doubled in the X direction by the pre-resolution converter 170, and the enlarged image is the pre-filter processor 140. To be supplied.

  FIG. 24 is an explanatory diagram showing processing executed on one block image by the previous resolution conversion unit 170.

  FIG. 24A is an explanatory diagram showing a block image supplied to the previous resolution conversion unit 170. FIG. 24B is an explanatory diagram showing a block image that has undergone resolution enlargement processing (X-direction enlargement processing) by the previous resolution conversion unit 170. FIG. 24C is an explanatory diagram showing image block processing in the pre-filter processing unit 140.

  As shown in FIGS. 24A and 24B, the size of the block image after the resolution conversion is 224 × 125 in the horizontal direction. In this embodiment, the pre-resolution conversion unit 170 performs the above-described enlargement processing (processing that doubles the resolution in the X direction) by a linear interpolation enlargement method. In this case, the pre-resolution conversion unit 170 generates a one-pixel invalid pixel at the right end of the block image (because the rightmost pixel cannot refer to the right adjacent pixel).

  Then, as shown in FIG. 24C, the block image (the size of the block image is 224 × 125 in the horizontal direction) input to the pre-filter processing unit 140 is converted to 25 by the pre-filter processing unit 140 around the target pixel. A filter process for referring to × 25 pixels is performed. Then, the pre-filter processing unit 140 supplies the block image after the filter processing to the block enlargement / reduction unit 220. As shown in FIG. 23C, in the block image after the processing by the pre-filter processing unit 140 by the above-described filter processing, 12 invalid pixels are generated at the left end, the right end, the upper end, and the lower end, respectively. In addition, as described above, since one invalid pixel is generated in the previous-stage previous resolution conversion unit 170 at the right end, a total of 13 pixels become invalid pixels in the previous resolution conversion unit 170 and the previous filter processing unit 140.

  The block image supplied to the block enlargement / reduction unit 220 is subjected to enlargement / reduction processing (here, 133% enlargement processing) by the block enlargement / reduction unit 120B, and the enlarged block image is supplied to the post-filter processing unit 150. Is done.

  FIG. 25 is an explanatory diagram showing an example of enlargement processing for an image block executed by the block enlargement / reduction unit 120B.

  FIG. 25A is an explanatory diagram showing a block image supplied to the block enlargement / reduction unit 120B. FIG. 25B is an explanatory diagram showing an example of a block image enlarged in the X direction by the block enlargement / reduction unit 120B. FIG. 25C is an explanatory diagram showing an example of a block image enlarged in the Y direction by the block enlargement / reduction unit 120B. FIG. 25D is an explanatory diagram showing an example of the enlargement process in the X direction performed by the block enlargement / reduction unit 120B. FIG. 25E is an explanatory diagram showing an example of the enlargement process in the Y direction performed by the block enlargement / reduction unit 120B.

  As shown in FIGS. 25 (a) to 25 (c), the block image (width 224 × length 125) supplied to the block enlargement / reduction unit 120B is first processed in the X direction by the X direction enlargement / reduction unit 121B. The image is enlarged (the block image size is 260 × 125 in the horizontal direction), and then enlarged and output in the Y direction by the Y-direction enlargement / reduction unit 122B (the block image size is 260 × vertical 125).

  As shown in FIG. 25D, in the X-direction enlargement performed by the X-direction enlargement / reduction unit 121B, the X-direction enlargement / reduction counter 121a is at the head of the line of each block image, and the X-direction of the block. Is set to the initial value of the enlargement / reduction counter corresponding to the block number. In the X direction enlargement / reduction unit 121B, for example, if the block number in the X direction is 2, the X direction enlargement / reduction counter 121a is set to 61.

  In the X direction enlargement / reduction unit 121B, the X direction skip counter 121c that starts counting from the left end of the block image has a predetermined value (12 in this example) common to all blocks, and the X direction skip counter 121c in the X direction of the block image. After the input pixels are ignored until the total value (12 + 1 = 13 in this example) of the fine adjustment skip value (1 in the example) corresponding to the block number (the invalid pixel 12 at the left end of the block image generated in the previous processing) One extra pixel generated due to the convenience of the pixel and the reading position is deleted by the above operation), and enlargement is performed for each line according to the X direction enlargement / reduction counter 121a. Then, the X-direction enlargement / reduction unit 121B enlarges and outputs until the X-direction output counter 121b reaches a predetermined value (260 in this example) (the right end of the block generated in the preceding process by the above operation) 12 invalid pixels and extra pixels are deleted).

  When the Y-direction enlargement / reduction unit 122B performs the Y-direction enlargement process, the Y-direction enlargement / reduction counter 122a performs Y-direction enlargement / reduction corresponding to the block number in the Y direction of the block image on the first line of each block. The initial value of the counter 122a is set. For example, if the block number in the Y direction is 1, the initial value of the Y direction enlargement / reduction counter 122a is set to 98. The Y-direction enlargement / reduction unit 122B ignores the input pixel until the skip counter that starts counting from the upper end of the block reaches a predetermined value (12 in the example) (the invalid pixel 12 at the upper end of the block generated in the previous processing). The pixels are deleted by the above operation), and the enlargement is performed according to the Y direction enlargement / reduction counter 122a. Then, the Y direction enlargement / reduction unit 122B enlarges and outputs until the Y direction output counter 122b reaches a predetermined value (132 in the example) (the invalid pixel at the lower end of the block image generated in the preceding process by the above operation). 12 pixels and extra pixels are deleted).

  As described above, the block enlargement / reduction unit 120B enlarges the supplied block image, and the extra pixels generated due to the ineffective pixels at the end of the block image generated by the filter processing of the preceding filter processing unit 140 and the convenience of reading. Delete the pixels. The block enlargement / reduction unit 120B outputs the block images having the same size. The block image output from the block enlargement / reduction unit 120B is supplied to the post-filter processing unit 150.

  FIG. 26 is an explanatory diagram showing block image processing performed by the post-filter processing unit 150, the post-resolution conversion unit 180, and the block cut processing unit 160.

  FIG. 26A is an explanatory diagram showing a block image supplied to the post-filter processing unit 150. FIG. 26B is an explanatory diagram showing a block image that has been post-filtered by the post-filter processing unit 150. FIG. 26C is an explanatory diagram showing a block image whose resolution has been converted by the post-resolution conversion unit 180. FIG. 26D is an explanatory diagram showing a block image partially cut by the block cut processing unit 160.

  As shown in FIGS. 26A and 26B, the post-filter processing unit 150 performs 5 × 5 centering on the pixel of interest for the supplied block image (the size of the block image is 260 × 132). Filter processing for referring to the pixels is performed. Then, the post-filter processing unit 150 supplies the filtered block image to the post-resolution conversion unit 180. As shown in FIG. 26B, by the filter processing of the block image by the post-filter processing unit 150, two invalid pixels are generated at the left end, the right end, the upper end, and the lower end in the processed block image.

  As illustrated in FIG. 26C, the post-resolution conversion unit 180 enlarges the supplied block image (the size of the block image is 260 × 132 in the Y direction) twice in the Y direction, and enlarges the block image. Is supplied to the block cut processing unit 160. As shown in FIG. 26C, the size of the block image whose resolution is converted by the post-resolution conversion unit 180 is 260 × 264. In this embodiment, the post-resolution conversion unit 180 may perform the above-described double enlargement process on the block image by a simple enlargement method. In this case, in the block image that is enlarged by the post-resolution conversion unit 180, invalid pixels are not generated along with the enlargement process. Note that the invalid pixels at the upper end and the lower end of the block image enlarged by the post-resolution conversion unit 180 are expanded by the enlargement in the Y direction, so that four invalid pixels are generated at the upper end and the lower end. Become.

  As shown in FIG. 26 (d), the block cut processing unit 160, with respect to the supplied block image (the size of the block image is horizontal 260 × vertical 264), invalid pixels (at the end of the block image generated in the previous stage processing) Here, 2 pixels each at the left and right ends and 4 pixels each at the top and bottom are deleted (cut). Then, the block cut processing unit 160 supplies the block image (block image size is 256 × vertical 256) from which invalid pixels are cut to the block writing unit 130A.

  As in the first and second embodiments, the block writing unit 130A images the supplied block images at regular intervals in the X and Y directions (256 for the X direction and 256 for the Y direction). Write to the memory 60 to create image data G104 for one page.

(C-3) Effects of Third Embodiment According to the third embodiment, the following effects can be achieved.

  In the image processing apparatus 1B according to the third embodiment, resolution conversion and quantization processing (pre-resolution conversion unit 170, post-resolution conversion unit 180, before and after enlargement / reduction processing (enlargement / reduction processing unit 100B) at an arbitrary magnification, Even when the processing by the quantization processing unit 190 is performed, reading and writing of image data from the image memory 60 may be performed only by processing of two image data (G101 and G104) as in the second embodiment. . Therefore, in the image forming apparatus 1B of the third embodiment, when resolution conversion and quantization processing are performed before and after enlargement / reduction processing at an arbitrary magnification, as in the second embodiment, It is possible to reduce the access amount to increase the processing speed and the required memory capacity. In other words, the image processing apparatus 1B according to the third embodiment can reduce the memory capacity required for the image image memory 60 when performing resolution conversion and quantization processing before and after enlargement / reduction processing at an arbitrary magnification. , Can speed up the process.

  Further, in the image processing apparatus 1B of the third embodiment, the resolution of the image data output by the image input unit 10 and the image output unit 50 by resolution conversion processing (processing by the pre-resolution conversion unit 170 and the post-resolution conversion unit 180). Can be processed in accordance with the expected resolution of the image data.

(D) Fourth Embodiment Hereinafter, an image processing apparatus and method and an image forming apparatus according to a fourth embodiment of the present invention will be described in detail with reference to the drawings.

(D-1) Configuration of Fourth Embodiment FIG. 27 is a block diagram showing a functional configuration of an image forming apparatus 1C according to the fourth embodiment of the present invention, and is the same as or corresponding to the portion shown in FIG. The same or corresponding symbols are attached.

  The fourth embodiment is different from the third embodiment in that the enlargement / reduction processing unit 100B is replaced with the enlargement / reduction processing unit 100C and a thumbnail image output unit 70 is added. In the block enlargement / reduction unit 120C of the third embodiment, a thumbnail reduction unit 200 as a size re-changing unit and a thumbnail writing unit 210 as a re-changed image generation unit are added. It is different from the embodiment.

  For example, a case is assumed where the image processing apparatus of the present invention is applied to a multifunction machine. When the image processing apparatus includes a display device such as a display (touch panel display of an operation panel) in addition to an image output unit for printing (image formation) on printing paper (medium), the thumbnail of the scanned document There may be a case where a configuration for displaying (reduced image) on the display is required. In this case, in the image processing apparatus, in addition to the image data necessary for printing on the printing paper, it is necessary to generate thumbnail image data to be displayed on the display.

  Therefore, the image processing apparatus 1C according to the fourth embodiment includes a thumbnail reduction unit 200, a thumbnail writing unit 210, and a thumbnail image as components for generating and outputting image data in a format different from that of the image output unit 50. An output unit 70 is provided.

  Here, as an example, it is assumed that the image output unit 50 functions as an image forming unit that performs printing (image formation) on printing paper (medium). The thumbnail image output unit 70 will be described as functioning as a display output unit that displays and outputs a thumbnail image (a reduced image corresponding to the image data G104 supplied to the image output unit 50) on a display. That is, description will be made assuming that the thumbnail image output unit 70 outputs an image reduced to a size smaller than the image output by the image output unit 50.

  The thumbnail reduction unit 200 performs thumbnail reduction for each block image of the block image supplied from the block cut processing unit 160 and supplies the reduced block image to the thumbnail writing unit 210.

  The thumbnail writing unit 210 sequentially writes the block images reduced by the thumbnail reduction unit 200 to the image memory 60 to generate image data G201 for one screen.

  In the block image input to the thumbnail writing unit 210, overlapping pixels between blocks are cut by the operation of the preceding stage (in this embodiment, the block processing unit 230). Further, since the width and height of each block image supplied to the thumbnail writing unit 210 are constant, the thumbnail writing unit 210 writes block images to the image memory 60 at regular intervals in the X direction and the Y direction. Thus, image data G201 for one page can be created.

  The display as the thumbnail image output unit 70 is, for example, a display device used for an operation panel or the like of a copier or a multifunction peripheral. The image data G201 written by the thumbnail writing unit 210 is read from the image memory 60, and the image data G201 is read out. A thumbnail image corresponding to is displayed and output.

  FIG. 28 is an explanatory diagram showing an image based on the image data G201 displayed on the display of the thumbnail image output unit 70.

  Here, for example, image data set in the block enlargement / reduction unit 120C according to a user operation (for example, an operation on an operation panel including a display as the thumbnail image output unit 70 provided in the image processing apparatus 1C). You may make it accept the magnification of G104.

  28 (a), 28 (b), and 28 (c), the magnifications set in the block enlargement / reduction unit 120C (for example, magnifications designated by the user) are 100%, 41%, and 133%, respectively. In this case, the image of the image data G201 displayed on the thumbnail image output unit 70 is shown.

  That is, the thumbnail reduction unit 200 reduces the input block image to a resolution corresponding to the display size (the number of pixels in the vertical and horizontal directions) of the thumbnail image output unit 70 (the image displayed on the normal display). Since the resolution is lower than the resolution of the image used for printing, only reduction is performed). Since the display resolution of the thumbnail reduction unit 200 varies depending on the device to which it is applied, the thumbnail reduction unit 200 needs to perform reduction at an arbitrary magnification. However, if the thumbnail reduction unit 200 completely supports reduction at an arbitrary magnification, the size of the block image to be output changes for each block image, or a block similar to the block enlargement / reduction unit 120B in the previous stage. A complicated configuration (for example, the same fairness as that of the block enlargement / reduction unit 120B) is required such that the initial value of the enlargement / reduction counter is required every time. Therefore, the thumbnail reduction unit 200 determines the denominator of the magnification based on the size of the input block image as described below, and determines the denominator of the determined magnification and the target magnification (the magnification received from the user, That is, it is preferable to determine the numerator of magnification from the magnification set in the block enlargement / reduction unit 120C.

  In the following formulas (66) to (69), xbase_t and xratio_t represent the denominator and the numerator value of the magnification in the X direction applied to the thumbnail reduction unit 200, respectively. Further, ybase_t and yratio_t represent the denominator and numerator value of the magnification in the Y direction applied to the thumbnail reduction unit 200, respectively. Furthermore, xscale and yscale indicate the magnification in the X direction and the magnification in the Y direction, respectively, which are targets for the thumbnail reduction unit 200. Here, xscale and yscale are respectively the resolution of the block image supplied to the thumbnail reduction unit 200 (that is, the resolution of the image data G104 supplied to the image output unit 50), and the display resolution of the thumbnail image output unit 70. A magnification based on the ratio of

(X-direction magnification denominator xbase_t of thumbnail reduction unit 200) =
(Block width input to thumbnail reduction unit 200) (66)
(X-direction magnification molecule xratio_t of thumbnail reduction unit 200) =
(X-direction magnification denominator xbase_t of thumbnail reduction unit 200)
X (target magnification xscale in X direction) (67)
(Y-direction magnification denominator ybase_t of thumbnail reduction unit 200) =
(Block height input to thumbnail reduction unit 200) (68)
(Y-direction magnification molecule yratio_t of thumbnail reduction unit 200) =
(Y-direction magnification denominator ybase_t of thumbnail reduction unit 200)
× (Target Y-direction magnification yscale) (69)
In the thumbnail reduction unit 200, by applying the magnification described above, the initial value of the enlargement / reduction counter for each block becomes constant for all blocks. Therefore, the thumbnail reduction unit 200 can perform reduction processing close to arbitrary magnifications in the X direction and the Y direction with a simple configuration including only the reduction counter in the X direction and the reduction counter in the Y direction. The purpose is to provide auxiliary display, and there is no problem if the display device can be reduced to a resolution close to that expected by the display device).

(D-2) Operation of Fourth Embodiment Hereinafter, the operation of the image forming apparatus 1 </ b> C of the fourth embodiment will be described focusing on the difference from the operation of the third embodiment. In the fourth embodiment, as described above, the thumbnail image processing configuration (the thumbnail reduction unit 200, the thumbnail writing unit 210, and the thumbnail image output unit 70) is added to the image forming apparatus 1B of the third embodiment. Therefore, only the operation of these components will be described.

  First, details of the reduction processing in the X direction and the Y direction performed by the thumbnail reduction unit 200 will be described with reference to the flowchart of FIG.

  The flowchart in FIG. 29 illustrates the X-direction reduction processing for the data for one line of the block image performed by the thumbnail reduction unit 200. In FIG. 29, xcnt_t is a reduction counter used in the processing of the thumbnail reduction unit 200.

  First, in step S701, the thumbnail reduction unit 200 resets the reduction counter xcnt_t to 0 at the head of the line.

  In step S702, the thumbnail reduction unit 200 determines whether the value of the reduction counter xcnt_t is smaller than the value of the numerator (xratio_t) of the magnification. If it is smaller, the process proceeds to step S703 and outputs the pixel. The process proceeds to step S705 without performing output.

  In step S703, the thumbnail reduction unit 200 outputs a pixel, adds the denominator value xbase_t of the magnification to the reduction counter xcnt_t, and proceeds to step S704. For example, the pixel (pixel value) output from the thumbnail reduction unit 200 is the current pixel in the simple reduction method.

  In step S704, the thumbnail reduction unit 200 determines whether the value of the reduction counter xcnt_t updated in step S703 described above is greater than or equal to the numerator value xbase_t of the magnification. Update), otherwise the process proceeds to step S706.

  In step S705, the thumbnail reduction unit 200 subtracts the value of the numerator xrasio_t of the magnification from the value of the reduction counter xcnt_t, updates the input pixel position (the pixel immediately adjacent to the current pixel is set as the next current pixel), and step S706. Proceed to

  In step S706, the thumbnail reduction unit 200 determines whether one line has been completed (determines whether all the pixels in the line being processed have been output). If one line has been completed, the one-line processing ends ( The process of the next input pixel line is performed). If not reached, the process returns to step S702 described above.

  As described above, the thumbnail reduction unit 200 performs the reduction process for all the X-direction lines of one block image. The thumbnail reduction unit 200 performs the same processing in the X direction and the Y direction of each block image, and reduces and outputs each block image.

  Next, the specific operation of the entire block enlargement / reduction unit 120C will be described.

  In the following description of the operation, as in the third embodiment, image data G101 (width 300 DPI × length 600 DPI) having a width of 3840 pixels and a height of 5120 pixels is enlarged at a magnification of 133% and reduced at a magnification of 41%. An example of the case will be described.

  In the following description, xbase_t and xratio_t represent the denominator and the numerator value of the magnification in the X direction, respectively. Further, ybase_t and yratio_t represent the denominator and the numerator value of the magnification in the Y direction, respectively.

  In the following description of the operation, as in the third embodiment, the pre-filter processing unit 140 performs a filter process for referring to 25 × 25 pixels around the target pixel, and the post-filter processing unit 150 selects the target pixel. Filter processing for referring to a 5 × 5 pixel is performed at the center, the pre-resolution conversion unit 170 performs processing for doubling the X-direction resolution, and the post-resolution conversion unit 180 doubles the Y-direction resolution. It is assumed that the quantization processing unit 190 performs a process of converting 8-bit image data per pixel into 1-bit image data per pixel. In the following description of the operation, the pre-filter processing unit 140, the block enlargement / reduction unit 120B, the post-filter processing unit 150, and the post-resolution conversion processing unit 330 are image data for 288, 264, 262, and 262 pixels, respectively ( It is assumed that a line memory that holds (pixel value) is provided, and that the block width that can be output in each processing unit is the above value.

  Note that the calculation and operation of parameters necessary for the processing units other than the thumbnail reduction unit 200 and the thumbnail writing unit 210 of the enlargement / reduction processing unit 100C are the same as those in the third embodiment, and a description thereof will be omitted.

  In the following, regarding the operations of the thumbnail reduction unit 200 and the thumbnail writing unit 210 of the enlargement / reduction processing unit 100C, the resolution of the image data expected by the thumbnail image output unit 70 (resolution as the display specifications) is 60 DPI horizontally. A case where it is 60 DPI will be described as an example.

  When the enlargement process of 133% is performed in the block enlargement / reduction unit 120C, the block image size supplied to the thumbnail reduction unit 200 (the size of the block image output from the block cut processing unit 160) is 256 × 256 in length. (As described in FIG. 22A). Further, when 41% reduction processing is performed in the block enlargement / reduction unit 120C, the block image size supplied to the thumbnail reduction unit 200 is 96 × 256 (as described in FIG. 22B above). It becomes.

  When the enlargement process of 133% is performed by the block enlargement / reduction unit 120C, the denominator of the magnification applied by the thumbnail reduction unit 200 is 256, the denominator xbase_t of the magnification in the X direction, and 256 the denominator ybase_t of the magnification in the Y direction. Become. In addition, when 41% reduction processing is performed in the block enlargement / reduction unit 120C, the denominator of the magnification applied by the thumbnail reduction unit 200 is 96 in the denominator xbase_t in the X direction and ybase_t in the Y direction. 256.

  Here, as described above, the resolution of the block image supplied to the thumbnail reduction unit 200 is horizontal 600 DPI and vertical 1200 DPI. Therefore, in this case, the target magnification xscale in the X direction for reduction performed by the thumbnail reduction unit 200 is 0.1, and the target magnification yscale in the Y direction is 0.05.

  Therefore, here, when the enlargement process of 133% is performed by the block enlargement / reduction unit 120C, the numerator xratio_t of the magnification in the X direction applied by the thumbnail reduction unit 200 is 256 × 0.1 = 25, and the magnification in the Y direction is The molecule yratio_t is 256 × 0.05 = 12. Further, when 41% reduction processing is performed in the block enlargement / reduction unit 120C, the numerator xratio_t with the magnification in the X direction is 96 × 0.1 = 9, and the numerator ratio_t with the magnification in the Y direction is 256 × 0.05 = 12. It becomes.

  Accordingly, when the enlargement process of 133% is performed in the block enlargement / reduction unit 120C, the value of the reduction factor (xratio_t / xbase_t) in the X direction performed by the thumbnail reduction unit 200 is 0.09765625, and the reduction factor in the Y direction. The value (yratio_t / ybase_t) is 0.046875. In addition, when 41% reduction processing is performed in the block enlargement / reduction unit 120C, the reduction ratio value (xratio_t / xbase_t) in the X direction performed by the thumbnail reduction unit 200 is 0.09375, and the reduction ratio in the Y direction is The value (yratio_t / ybase_t) is 0.046875.

  Accordingly, when the enlargement process of 133% is performed in the block enlargement / reduction unit 120C, the block image size output by the thumbnail reduction unit 200 is 25 × 12.

Further, when 41% reduction processing is performed in the block enlargement / reduction unit 120C, the block image size output by the thumbnail reduction unit 200 is 9 × 12 in width.

  Then, the block image output by the thumbnail reduction unit 200 is supplied to the thumbnail writing unit 210.

  When the enlargement process of 133% is performed by the block enlargement / reduction unit 120C, the thumbnail writing unit 210 stores the pixel values (pixel values of each block image) at a constant interval of 25 in the X direction and 12 in the Y direction. The image data G201 for displaying thumbnails for one page is created. When 41% reduction processing is performed by the block enlargement / reduction unit 120C, the thumbnail writing unit 210 sets pixel values (pixel values of each block image) at regular intervals of 9 in the X direction and 12 in the Y direction. Write to the memory 60 and create image data G201 for thumbnail display for one page.

  With the above processing, when the enlargement process of 133% is performed in the block enlargement / reduction unit 120C, the image of the thumbnail display image data G201 is an image of horizontal 998 × height 639. Further, when 41% reduction processing is performed in the block enlargement / reduction unit 120C, the image of the thumbnail display image data G201 is a horizontal 296 × vertical 197 image.

(D-3) Effects of the fourth embodiment According to the fourth embodiment, the following effects can be achieved.

  In the image processing apparatus 1C according to the fourth embodiment, even when image data having a plurality of different resolutions such as image data for printing and image data for thumbnails are generated, the image is stored from the memory 60 only for generating each. There is no need to read and process data.

  For example, in the first to third embodiments, in addition to the image output unit 50, an image output unit that expects image data whose resolution is different from the image data expected by the image output unit 50 (for example, the thumbnail image output unit 70). ), It is necessary for the processing unit of each block image to process the block image related to the image data expected by the image output unit having a different resolution or the like. However, in the image processing apparatus 1C according to the fourth embodiment, the steps up to the block cut processing unit 160 are shared by the image output unit 50 and the thumbnail image output unit 70, and therefore the processing units ( By providing only the thumbnail reduction unit 200 and the thumbnail writing unit 210), it is possible to generate image data having a resolution expected by the thumbnail image output unit 70.

  Therefore, in the image processing apparatus 1C, when creating image data having a plurality of different resolutions, it is possible to reduce the memory capacity required for the image memory 60 and increase the processing speed.

  Further, in the image processing apparatus 1C, the created thumbnail image data is data that reflects the processing result such as the user's magnification designation, so that the contents such as printing acquired by the user are appropriately displayed and output. Can do.

(D) Other Embodiments The present invention is not limited to the above-described embodiments, and may include modified embodiments as exemplified below.

(D-1) The image forming apparatus of each of the embodiments described above can be applied to an apparatus that performs image processing including arbitrary magnification on image data, such as a copier, a multifunction peripheral, and a FAX.

  The means for outputting an image processed by the image processing apparatus of the present invention is not limited to image formation such as printing, but is displayed on a display or output as external data (for example, a host PC) or a recording medium (electronic data). For example, it may be recorded on a CD-ROM or HDD. For example, the image processing apparatus mounted on the image forming apparatus of each of the above embodiments is not limited to the image forming apparatus, and is applied to apparatuses that perform other image processing (for example, digital cameras, scanners, digital video recorders, etc.). You may make it do.

(D-2) In the image forming apparatus (image processing apparatus) of each of the above embodiments, when the image is divided into block images, the enlargement / reduction process is performed in the X direction and the Y direction. The enlargement / reduction process may be performed only in the direction (X direction or Y direction). In this case, the image forming apparatus (image processing apparatus) may perform block image unit division only in the direction (X direction or Y direction) in which the enlargement / reduction process is performed. (D-3) In the image forming apparatus (image processing apparatus) of each of the above embodiments, the pre-filter processing unit and / or the post-filter processing unit may be omitted.

(D-3) In the third embodiment, the pre-resolution conversion unit 170, the post-filter processing unit 150, and the quantization processing unit 190 are included, but some of them may be omitted. .

  DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 10 ... Image input part, 20 ... Pre filter process part, 100 ... Enlargement / reduction process part, 110 ... Block reading part, 120 ... Block enlargement / reduction part, 121 ... X direction enlargement / reduction part, 121a ... X direction enlargement / reduction counter, 121b ... X direction output counter, 122 ... Y direction enlargement / reduction unit, 122a ... Y direction enlargement / reduction counter, 122b ... Y direction output counter, 130 ... block writing unit, 30 ... after Filter processing unit, 50... Image output unit, 60.

Claims (27)

A block image reading means for extracting a plurality of block images from the input image and sequentially reading them;
For each block image read by the block image reading means, a size changing means for performing a size changing process at a predetermined magnification;
Resized image generating means for generating a resized image obtained by resizing the input image at the predetermined magnification based on the block image whose size has been changed by the size changing means ;
The size changing means performs a size changing process for each line constituting the block image,
The size changing means uses a size change counter that manages the positional relationship between the positions of the pixels constituting the line of the block image before the size changing process and the positions of the pixels constituting the line of the block image after the size changing process. An image processing apparatus that performs size change processing for each line . The size changing means obtains an initial value of the size change counter for each block image, and when performing the size change processing for the lines constituting each block, the size change counter value is The image processing apparatus according to claim 1 , wherein the image processing apparatus is reset to an initial value relating to a block. Manages the size of each block image processed by the image processing apparatus, so that the size of the block image after the conversion processing by the size changing means is within a range not exceeding the processing upper limit of the size changing means. The image processing apparatus according to claim 2 , further comprising a block management unit that determines a size of a block image to be read by the block image reading unit. Each of the block images read by the block image reading means has an overlapping area between the block image and an adjacent block image,
The image processing apparatus according to any one of claims 1 to 3 , wherein the size-changed image generation unit performs a process of excluding an invalid portion output for each block image after the size change process. For the input image supplied to the block image reading unit, a pre-filter processing unit that performs a pre-filter process before the processing of the block image reading unit;
The image processing apparatus according to any one of claims 1 to 4, wherein the resized image that the resized image generating means has generated, further comprising a filter processing unit after performing the post-filtering. For the block image read by the block image reading means, pre-filter processing means for performing pre-filter processing that requires reference to peripheral pixels in the region to be filtered,
For each block image the size changing means makes a resizing process, to claim 1, characterized in that it comprises a filtering means after the reference of the peripheral pixel in the region of the filter processing target to filter after required The image processing apparatus described. Each of the block images read by the block image reading means has an overlapping area between the block image and an adjacent block image,
The size-changed image generation means performs a process of excluding the output of the first invalid area that overlaps with an adjacent block image for each block image after the size change process,
The image processing apparatus according to claim 6 , further comprising: a block cut unit that excludes an output of a second invalid area that overlaps an adjacent block image with respect to a block image that has been processed by the post filter processing unit. . Managing the size of each block image processed by the image processing apparatus, the size of the block image supplied to the pre-filter processing means, the size of the block image after the conversion processing by the size changing means, The block image reading means is arranged so that the size of the block image supplied to the post-filter processing means and the size of the block image supplied to the block cut means are within a range not exceeding the processing upper limit related to each processing. The image processing apparatus according to claim 7 , further comprising a block management unit that determines a size of a block image to be read.   The image processing apparatus according to claim 1, further comprising a resolution conversion unit that performs resolution conversion of a block image before the size change unit and / or after the size change unit. The image processing apparatus according to claim 9 , further comprising a quantization processing unit that performs a quantization process on the block image supplied to the size-changed image generation unit. A size re-changing unit for performing a size re-changing process for changing the size of the block image again at a later stage than the size changing unit;
Resize image generating means for generating a resize image having a different size from the resize image based on the block image subjected to the resize process by the resize means, further comprising: The image processing apparatus according to claim 9 or 10 . The image processing apparatus according to claim 11 , wherein the resizing unit performs a block image reduction process. In the image processing method performed by the image processing apparatus,
A block image reading unit, a size changing unit, and a size-changing image generating unit;
The block image reading means extracts a plurality of block images from the input image, sequentially reads them,
The size changing means performs a size changing process at a predetermined magnification for each of the block images read by the block image reading means,
The size-changed image generation unit generates a size-changed image obtained by resizing the input image at the predetermined magnification based on the block image whose size has been changed by the size-changing unit .
The size changing means performs a size changing process for each line constituting the block image,
The size changing means uses a size change counter that manages the positional relationship between the positions of the pixels constituting the line of the block image before the size changing process and the positions of the pixels constituting the line of the block image after the size changing process. An image processing method comprising performing a size change process for each line . An image forming apparatus comprising: an image processing apparatus that processes an input image; and an image forming unit that forms an image processed by the image processing apparatus on a medium.
The image processing apparatus includes:
A block image reading means for extracting a plurality of block images from the input image and sequentially reading them;
For each block image read by the block image reading means, a size changing means for performing a size changing process at a predetermined magnification;
Based on the block image resizing is performed in the size changing means, the input image have a size-changed image generating means for generating a resized image size changing process at the predetermined magnification,
The size changing means performs a size changing process for each line constituting the block image,
The size changing means uses a size change counter that manages the positional relationship between the positions of the pixels constituting the line of the block image before the size changing process and the positions of the pixels constituting the line of the block image after the size changing process. An image forming apparatus that performs a size changing process for each line . A block image reading means for extracting a plurality of block images from the input image and sequentially reading them;
For each block image read by the block image reading means, a size changing means for performing a size changing process at a predetermined magnification;
Resized image generating means for generating a resized image obtained by resizing the input image at the predetermined magnification based on the block image whose size has been changed by the size changing means;
In the block image reading means, the size of the block image extracted from the input image is varied according to the predetermined magnification, and the size of the block image extracted from the input image is determined by the predetermined magnification.
An image processing apparatus. The size changing means performs a size changing process for each line constituting the block image,
The size changing means uses a size change counter that manages the positional relationship between the positions of the pixels constituting the line of the block image before the size changing process and the positions of the pixels constituting the line of the block image after the size changing process. The image processing apparatus according to claim 15, wherein size change processing is performed for each line. The size changing means obtains an initial value of the size change counter for each block image, and when performing the size change processing for the lines constituting each block, the size change counter value is The image processing apparatus according to claim 16, wherein the image processing apparatus is reset to an initial value relating to a block. Manages the size of each block image processed by the image processing apparatus, so that the size of the block image after the conversion processing by the size changing means is within a range not exceeding the processing upper limit of the size changing means. The image processing apparatus according to claim 17, further comprising a block management unit that determines a size of a block image read by the block image reading unit. Each of the block images read by the block image reading means has an overlapping area between the block image and an adjacent block image,
The image processing apparatus according to any one of claims 16 to 18, wherein the size-changed image generation unit performs a process of excluding an invalid portion output for each block image after the size change process. For the input image supplied to the block image reading unit, a pre-filter processing unit that performs a pre-filter process before the processing of the block image reading unit;
Post-filter processing means for performing post-filter processing on the size-changed image generated by the size-change image generating means;
The image processing apparatus according to claim 15, further comprising: For the block image read by the block image reading means, pre-filter processing means for performing pre-filter processing that requires reference to peripheral pixels in the region to be filtered,
Post-filter processing means for performing post-filter processing that requires reference to surrounding pixels of the region to be filtered for each of the block images subjected to the size change processing by the size changing means;
The image processing apparatus according to claim 15 or 16, further comprising: Each of the block images read by the block image reading means has an overlapping area between the block image and an adjacent block image,
The size-changed image generation means performs a process of excluding the output of the first invalid area that overlaps with an adjacent block image for each block image after the size change process,
The block image after the processing by the post-filter processing unit is further provided with a block cut unit that excludes the output of the second invalid area that overlaps the adjacent block image.
The image processing apparatus according to claim 21. Managing the size of each block image processed by the image processing apparatus, the size of the block image supplied to the pre-filter processing means, the size of the block image after the conversion processing by the size changing means, The block image reading means is arranged so that the size of the block image supplied to the post-filter processing means and the size of the block image supplied to the block cut means are within a range not exceeding the processing upper limit related to each processing. The image processing apparatus according to claim 22, further comprising block management means for determining a size of a block image to be read. The image processing apparatus according to claim 21, further comprising a resolution conversion unit that performs resolution conversion of a block image at a stage before the size changing unit and / or at a stage after the size changing unit. The image processing apparatus according to claim 24, further comprising a quantization processing unit that performs a quantization process on the block image supplied to the size-changed image generation unit. A size re-changing unit for performing a size re-changing process for changing the size of the block image again at a later stage than the size changing unit;
Resize image generating means for generating a resize image having a different size from the resize image based on the block image subjected to the resize process by the resize means, further comprising: The image processing apparatus according to claim 24 or 25. 27. The image processing apparatus according to claim 26, wherein the resize changing unit performs a block image reduction process.

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