JP6638452B2 - Image processing apparatus, image forming apparatus, and image processing program - Google Patents

Description

  The present invention relates to an image processing device, an image forming device, and an image processing program.

  2. Description of the Related Art Conventionally, an image processing apparatus and an image forming apparatus that remove a ground color (paper color) of a document at the time of copying or the like are known.

  For example, in Japanese Patent Application Laid-Open No. H10-157, the purpose of preventing deterioration in highlight reproducibility due to ground color removal is to determine whether or not a highlight is based on image data. A technique in which processing is performed using a background level for highlight (a luminance level regarded as a background), and processing is performed on a pixel determined to be not a highlight using a background level having lower luminance than that for highlight. Is disclosed.

JP 2008-005317 A

  However, the noise level (variation in reading sensitivity) of an image reader when reading a document has individual differences even for the same model, and as a result, the balance between the noise level and the background level is lost, and the ground color is not removed. It may fail. The failure of the ground color removal means, for example, that a part of the ground color remains or a light color in the document image is mistaken for the ground color and is erased.

  SUMMARY An advantage of some aspects of the invention is to provide an image processing apparatus, an image forming apparatus, and an image processing program that can suppress a failure in ground color removal even when a variation in reading sensitivity changes.

The image processing device according to claim 1 is
A ground color removing unit that removes the image of the document read by the document reader that reads the image of the document as a ground color to a higher density color as the variation in sensitivity in the document reader is larger;
Of the colors in the image of the document remaining after the ground color is removed by the ground color removing unit, the density of the color present in the density area adjacent to the density area of the ground color is determined by the sensitivity of the document reader. A concentration increasing portion that increases greatly as the variation increases,
An image output unit that outputs an image of the document whose background color has been removed by the background color removal unit and the density of which has been increased in the density increasing unit ;
It is characterized by having.

The image forming apparatus according to claim 2 ,
A document reader for reading the image of the document,
A ground color removing unit that removes the image of the document read by the document reader as a background color to a higher density color as the variation in sensitivity in the document reader is larger;
Of the colors in the image of the document remaining after the ground color is removed by the ground color removing unit, the density of the color present in the density area adjacent to the density area of the ground color is determined by the sensitivity of the document reader. A concentration increasing portion that increases greatly as the variation increases,
An image output unit that outputs an image of the document whose background color has been removed by the background color removal unit and the density of which has been increased in the density increasing unit ;
It is characterized by having.

The image processing program according to claim 3 is
Embedded in an information processing device, and the information processing device is
A ground color removing unit that removes the image of the document read by the document reader that reads the image of the document as a ground color to a higher density color as the variation in sensitivity in the document reader is larger;
Of the colors in the image of the document remaining after the ground color is removed by the ground color removing unit, the density of the color present in the density area adjacent to the density area of the ground color is determined by the sensitivity of the document reader. A concentration increasing portion that increases greatly as the variation increases,
An image output unit that outputs an image of the document whose background color has been removed by the background color removal unit and the density of which has been increased in the density increasing unit ;
Is operated as an image processing apparatus provided with

  According to the image processing apparatus according to the first aspect, the image forming apparatus according to the third aspect, and the image processing program according to the fourth aspect, it is possible to suppress the failure of the ground color removal even if the variation in the reading sensitivity changes. it can.

  According to the image processing apparatus of the second aspect, even if the variation in the reading sensitivity changes, the density of the color in the image remaining after the ground color is removed is stabilized.

FIG. 1 is a schematic configuration diagram of a multifunction peripheral corresponding to an embodiment of a copying apparatus of the present invention. It is a figure showing the principle of ground color removal in the comparative example of ground color removal processing. FIG. 14 is a diagram illustrating an example of a case where reading noise is large in a comparative example of the ground color removal processing. FIG. 14 is a diagram illustrating an example in which reading noise is small in a comparative example of the ground color removal processing. It is a figure which shows the principle of the ground color removal process in this embodiment, when a standard deviation is equal to a reference value. It is a figure which shows the principle of the ground color removal processing in this embodiment, when a standard deviation is larger than a reference value. It is a figure which shows the principle of the ground color removal processing in this embodiment, when a standard deviation is smaller than a reference value. FIG. 9 is a diagram illustrating the principle of density adjustment of a light-colored portion when the magnitude of read noise is large. FIG. 9 is a diagram illustrating the principle of density adjustment of a light-colored portion when the magnitude of reading noise is small. FIG. 2 is a functional block diagram illustrating a functional configuration of an image processing unit illustrated in FIG. 1. It is a flowchart showing the processing operation of ground color removal processing and density adjustment. It is a figure showing the correspondence table used by an adjustment part. FIG. 13 is a diagram illustrating a specific example of a correspondence table illustrated in FIG. 12. FIG. 14 is a diagram illustrating a specific example in a case where the standard deviation σ = 12. FIG. 9 is a diagram illustrating a specific example in a case where a standard deviation σ = 3.

  An embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a multifunction peripheral corresponding to an embodiment of the image forming apparatus of the present invention.

  An image reading unit 10 for reading an image from a document is provided at an upper portion of the multifunction device 1. The image reading unit 10 includes a lid 11 that opens and closes using a hinge as a rotation axis, a transparent platen glass 12 disposed directly below the lid 11, and an image reading sensor 13 disposed further below the platen glass 12. Provided. When reading an image by the image reading unit 10, the lid 11 is opened and the document is set downward on the platen glass 12. When the cover 11 is closed and the start button is pressed, the image of the original is read and image data is generated. The image reading sensor 13 extends in the depth direction of the multifunction device 1 (a direction perpendicular to the paper surface of FIG. 1), and sequentially reads images of the document while moving in the direction of arrow A to generate image data. The image reading unit 10 corresponds to an example of a document reader according to the present invention.

  The multifunction device 1 includes a control unit 21 for controlling the operation of the entire copying machine 1. The multifunction device 1 obtains image data from an external device such as a personal computer (PC), an internal telephone communication device (not shown), or the image reading unit 10 described above, and performs image processing on the image data. Is also provided. Further, the multifunction device 1 includes a plurality of operation buttons including the above-described start button and a display screen, and a user interface (UI) unit 22 that receives an operation input from a user and displays various information to the user. Is also provided. The image processing unit 23 has a function as an embodiment of the image processing apparatus of the present invention, and performs a ground color removal process for removing the ground color of the document from the image data obtained from the image reading unit 10. Details of the ground color removal processing will be described later. Although the function of the image processing unit 23 may be realized by hardware, in the present embodiment, an embodiment of the image processing program of the present invention is implemented by being incorporated in a so-called board computer which is a type of information processing apparatus. It is assumed that

  Further, the multifunction device 1 includes an image forming unit 30 that forms an image using a color material (here, toner as an example) of each color corresponding to image data of each color. The image formation in the image forming unit 30 is performed by image data obtained by reading by the image reading unit 10, image data obtained from an external device such as a PC, or a telephone communication device (not shown) inside the MFP 1. It is performed based on. That is, the multifunction peripheral 1 has the functions of a copier, a printer, and a facsimile. The image forming unit 30 corresponds to an example of the image forming unit according to the present invention.

  The image forming unit 30 according to the present embodiment includes a plurality (four in this example) of image forming engines 50. These image forming engines 50 are engines that form a toner image using toner of a corresponding color.

  An endless intermediate transfer belt 61 wound around rolls 62 and 63 is disposed above these image forming engines 50. The intermediate transfer belt 61 is circulated along four image forming engines 50 in a direction indicated by an arrow C on a circulating path. Circular moves.

  The toner images of each color formed by each image forming engine 50 are transferred onto the intermediate transfer belt 61 so as to be sequentially overlapped by the operation of each transfer device 55, and a color image is formed on the intermediate transfer belt 61. The color image on the intermediate transfer belt 61 is conveyed by the intermediate transfer belt 61 and is transferred onto a sheet by the operation of the secondary transfer device 71.

  A paper tray 31 that can be pulled out is provided below the image forming unit 30. In the sheet tray 31, sheets before image formation are stacked and stored as recording media used for image formation.

  The paper accommodated in the paper tray 31 is taken out by a pickup roll 81, conveyed by conveyance rolls 83 in the directions of arrows D and E, and the color image on the intermediate transfer belt 61 is transferred to the secondary transfer unit 71 at a position. It is transferred onto paper.

  The sheet on which the color image has been transferred is further conveyed in the direction of arrow F and passes through a fixing device 90, which is pressed and heated by the fixing device 90, whereby the color image on the sheet is fixed on the sheet. You.

  The sheet that has passed through the fixing unit 90 is further transported in the direction of arrow G by the transport roll 85, and is discharged onto the discharge tray 32 by the discharge roll 86.

  Here, the above-described background color removal processing will be described, but a comparative example will be described prior to the description of the present embodiment.

  FIG. 2 is a diagram illustrating the principle of ground color removal in a comparative example of ground color removal processing.

  FIG. 2 shows a luminance histogram in a highlight area of the document image, in which the horizontal axis represents luminance and the vertical axis represents the number of pixels. The brightness is high on the left side of the figure and low on the right side. That is, the image density is low on the left side of the figure and high on the right side. In any luminance histogram referred to in this specification, the vertical and horizontal axes are the same as those in FIG.

  The luminance histogram of FIG. 2 shows two peaks 101 and 102. The peak 101 on the high luminance side is a peak corresponding to the ground color of the document, and the peak 102 on the low luminance side is a light pixel in the document image. The corresponding peak. In the original document, it is assumed that both the ground color and the light color pixel have a single color. That is, if the luminance histogram is based on the original color of the document, the width of the two peaks 101 and 102 is 0. However, the luminance histogram in FIG. 2 is based on the pixel values of the original image read by the image reading unit 10 in FIG. 1, and each of the peaks 101 and 102 corresponds to the reading noise (reading sensitivity) of the image reading unit 10. (Variation). Here, the reading noise (variation in reading sensitivity) may be caused by either a temporal sensitivity difference in one sensor element or a sensitivity difference between a plurality of sensor elements.

  In the background color removal processing, a background color threshold value 103 is set, and a pixel having a pixel value on the higher luminance side than the threshold value 103 is regarded as a ground color pixel, and the pixel value is set to the highest luminance (that is, the lowest luminance value). (Density = pure white). At this time, in consideration of the reading noise of the image reading unit 10, all of the pixels included in the peak 101 of the ground color are reset, and some of the pixels included in the peak 102 of the light color pixels are reset. It is set to a value that will remain.

  However, the reading noise of the image reading unit 10 may change over time, or may differ between apparatuses of the same model. If the reading noises are different as described above, there is a possibility that the ground color removing process fails because the read noise does not match the set ground color threshold value 103.

  FIG. 3 is a diagram illustrating an example of a case where reading noise is large in a comparative example of the ground color removal processing.

  When the reading noise of the image reading unit 10 is large, the width of both the ground color peak 101 and the light color pixel peak 102 becomes large. For this reason, the ground color peak 101 has a portion 104 reaching a lower luminance side than the ground color threshold value 103, and the ground color remains in pixels corresponding to this portion 104.

  FIG. 4 is a diagram illustrating an example in which reading noise is small in a comparative example of the ground color removal processing.

  When the reading noise of the image reading unit 10 is small, the width of both the ground color peak 101 and the light color pixel peak 102 becomes small. For this reason, the entire area of the peak 102 of the light-color pixel is on the higher luminance side than the ground color threshold value 103, and the light color in the document image is lost without being reproduced.

  In the present embodiment, measures are taken to suppress such a failure.

  5 to 7 are diagrams illustrating the principle of the ground color removal processing according to the present embodiment.

  In the present embodiment, the magnitude of the reading noise is confirmed using the standard deviation at the peak 101 of the ground color. The standard deviation is compared with the reference value. If the standard deviation is larger than the reference value, it is determined that the read noise is large, and if the standard deviation is smaller than the reference value, it is determined that the read noise is small. Then, the threshold value of the ground color is changed according to the magnitude of the reading noise as described below.

  FIG. 5 shows an example in which the standard deviation at the ground color peak 101 is equal to the reference value. In this case, since the magnitude of the read noise is the magnitude of the read noise assumed at the time of design, the ground color is removed by the ground color threshold value 103 (the initially set threshold value) similar to the comparative example. Will be As a result, all the pixels included in the ground color peak 101 are reset, and some of the pixels included in the light color pixel peak 102 remain, and the light color portion of the document is reproduced.

  FIG. 6 shows an example where the standard deviation at the ground color peak 101 is larger than the reference value. In this case, since the magnitude of the read noise is larger than the magnitude of the read noise assumed at the time of design, the ground color can be removed by the threshold value 105 in which the threshold value 103 of the default ground color is changed to the low luminance side. Done. Both the ground color peak 101 and the light-colored pixel peak 102 are wider due to large read noise, but as a result of using the threshold 105 on the low luminance side, almost all the pixels included in the ground color peak 101 are reset. And the remaining ground color is avoided. Some of the pixels included in the peak 102 of the light-colored pixels remain, and the light-colored portion of the document is reproduced.

  FIG. 7 shows an example in which the standard deviation at the ground color peak 101 is smaller than the reference value. In this case, since the magnitude of the read noise is smaller than the magnitude of the read noise assumed at the time of design, the ground color is removed by the threshold 106 in which the threshold 103 of the ground color of the initial setting is changed to the high luminance side. Done. Both the ground color peak 101 and the light color pixel peak 102 have narrow widths, but as a result of the use of the threshold 106 on the high luminance side, many of the pixels included in the light color pixel peak 102 remain and the light color portion of the original document remains. Is reproduced. Further, all the pixels included in the ground color peak 101 are reset, and the ground color remaining is also avoided.

  As described above, in the present embodiment, even when the magnitude of the reading noise (variation in the reading sensitivity) fluctuates, the failure of the ground color removal is suppressed.

  Furthermore, in the present embodiment, the density adjustment is performed on the reproduced light-colored portion of the document as described below.

  FIG. 8 and FIG. 9 are diagrams illustrating the principle of density adjustment of a light-colored portion.

  Even in the conventional ground color removal processing, a part of the light color portion of the document is reset when the ground color is removed, so by increasing the density of each pixel for the remaining light color portion, the apparent density of the entire light color portion is reduced. Maintains the same as the manuscript. In the present embodiment, the initial density increase is the same as the conventional one. Then, the magnitude of the density increase is changed according to the magnitude of the reading noise as described below.

  FIG. 8 shows an example in which the magnitude of the reading noise is large. In this case, although the light-colored portion of the document remains after the ground color is removed, the low-luminance side , The number of pixels of the remaining light-colored portion 107 is small. For this reason, the density of each pixel is increased more than the initially set density, and the apparent density of the entire light-colored portion is maintained.

  FIG. 9 shows an example in which the magnitude of the read noise is small. In this case, the threshold 106 changed from the default ground color threshold 103 to the high luminance side is used. Many light-colored portions 108 are left after the removal. For this reason, the density increase of each pixel is suppressed to be smaller than the initially set density increase, and the apparent density of the entire light color portion is maintained.

  As described above, in the present embodiment, even if the magnitude of the reading noise (variation in the reading sensitivity) varies, the apparent density of the entire light-colored portion is stable.

  The processing described above is executed by the image processing unit 23 shown in FIG. Hereinafter, an example of a specific mechanism in which the image processing unit 23 executes the above processing will be described below.

  FIG. 10 is a functional block diagram illustrating a functional configuration of the image processing unit 23 illustrated in FIG.

  FIG. 10 shows only the functions related to the above-described background color removal processing and density adjustment among various functions of the image processing unit 23.

  The image processing unit 23 includes an analysis unit 110, an adjustment unit 120, and a processing unit 130.

  The analysis unit 110 acquires the image data of the document image from the image reading unit 10 shown in FIG. 1 and calculates the standard deviation of the ground color peak.

  Based on the standard deviation calculated by the analysis unit 110, the adjustment unit 120 determines a ground color threshold in the ground color removal processing (hereinafter, this threshold may be referred to as “removal amount”) and a density The amount of increase (hereinafter, this amount of increase may be referred to as a “pale color corresponding parameter”) is adjusted.

  The processing unit 130 performs ground color removal processing and density adjustment on the image data of the document image based on the removal amount and the light color corresponding parameter adjusted by the adjustment unit 120. The image data processed by the processing unit 130 is output to the control unit 21 shown in FIG. 1 and used for image formation.

  The combination of the adjustment unit 120 that adjusts the removal amount and the processing unit 130 that performs the ground color removal processing corresponds to an example of the ground color removal unit according to the present invention, and the adjustment unit 120 that adjusts a light color corresponding parameter is included. The combination of the processing unit 130 for performing the density adjustment corresponds to an example of the density increasing unit according to the present invention. In addition, the processing unit 130 that outputs image data to the control unit 21 is considered as an example of the image output unit according to the present invention, and the combination of the control unit 21 and the image forming unit 30 corresponds to the present invention. The image output unit is an example of outputting (forming) an image on a recording medium. The generated image data may be configured to be output to an external device such as a personal computer (PC) or a storage device included in the g image forming apparatus.

  Hereinafter, the processing operations of the background color removal processing and the density adjustment will be described in detail.

  FIG. 11 is a flowchart illustrating the processing operation of the background color removal processing and the density adjustment.

  The processing operation illustrated in FIG. 11 is executed by the control unit 21 illustrated in FIG. 1 and the image processing unit 23 illustrated in FIG. This processing operation corresponds to an operation as an embodiment of the image processing program of the present invention.

  This processing operation is started when a document is set on the image reading unit 10 shown in FIG. 1 and a start button is operated. When the processing operation is started, in step S101, the image reading unit 10 is controlled by the control unit 21 to scan a document and generate image data representing a document image.

  This image data is acquired by the analysis unit 110 shown in FIG. 10, and a histogram of the ground color is created (step S102). Specifically, a part of the original image represented by the image data, which is about several millimeters from the edge of the paper, is extracted, and a color histogram of each pixel included in this part is created. In addition, as a method of creating a histogram of the ground color, there is also a method of using the colors of the pixels of the entire original image and regarding the peak occurring on the highest luminance side as the ground color peak.

  Next, the analyzing unit 110 calculates the standard deviation of the ground color from the histogram of the ground color created in this way (step S103).

  Next, the adjustment unit 120 adjusts the removal amount and the light color corresponding parameter based on the standard deviation of the ground color (steps S104 and S105). In the present embodiment, the adjustment of the removal amount and the light color corresponding parameter in the adjustment unit 120 is performed according to a correspondence table described below.

  FIG. 12 is a diagram illustrating a correspondence table used in the adjustment unit 120.

  The correspondence table 140 is provided with a standard deviation column 141, a removal amount column 142, and a pale color correspondence para column 143.

  In the standard deviation column 141, five ranges are described as ranges of the standard deviation σ. The central range (B ≦ σ <C) of the five ranges is the reference range of the standard deviation σ, and when the standard deviation σ within this reference range is obtained, the reading noise in the image reading unit 10 is This is the size assumed at the time of design. Then, in association with this reference range (B ≦ σ <C), a value “0” indicating that the adjustment is zero and the initial value is maintained is described in the removal amount column 142 and the pale color correspondence column 143. Have been.

  Of the five ranges described in the standard deviation column 141, the removal amount is associated with a range (C ≦ σ <D, D ≦ σ) in which the standard deviation σ is larger than the reference range (B ≦ σ <C). In the column 142, values “+ a” and “+ 2a” indicating that the ground color removal amount is increased (that is, the threshold value of the ground color is changed to the lower luminance side) are described, and in the pale color corresponding para column 143, Values “+ b” and “+ 2b” indicating increasing the density increase of the light-colored pixels are described. Also, of the two ranges (C ≦ σ <D, D ≦ σ) in which the standard deviation σ is larger than the reference range, the range in which the standard deviation σ is larger (D ≦ σ) includes the ground color removal amount and the light color. Values “+ 2a” and “+ 2b” representing increasing the density increase of the pixel are described.

  In addition, among the five ranges described in the standard deviation column 141, the ranges (σ <A, A ≦ σ <B) in which the standard deviation σ is smaller than the reference range (B ≦ σ <C) are In the removal amount column 142, values “−a” and “−2a” indicating that the background color removal amount is reduced (that is, the background color threshold value is changed to a higher luminance side) are described. 143 describes values “−b” and “−2b” indicating that the increase in the density of the light-colored pixels is reduced. Further, of the two ranges (σ <A, A ≦ σ <B) in which the standard deviation σ is smaller than the reference range, the ground color removal amount and the light color Values “−2a” and “−2b” indicating that the increase in pixel density is further reduced are described.

  In steps S104 and S105 in FIG. 11, the removal amount of the ground color is adjusted according to the value described in the correspondence table 140 (step S104), and the pale color correspondence parameter is changed (step S105). As described above, in the present embodiment, the removal amount and the light color corresponding parameter are adjusted stepwise with respect to the change in the standard deviation σ indicating the magnitude of the reading noise.

  When the removal amount and the light color correspondence parameter are adjusted in this way, the processing unit 130 shown in FIG. 10 performs the ground color removal processing and the density adjustment on the image data according to the adjusted removal amount and the light color correspondence parameter. Is performed (step S106).

  Then, the image data on which the ground color removal processing and the density adjustment have been performed are sent to the image forming section 30 by the control section 21 shown in FIG. 1, and an image is formed on a sheet (step S107).

  Next, a specific adjustment example of the removal amount and the pale color correspondence parameter will be described.

  FIG. 13 is a diagram illustrating a specific example of the correspondence table illustrated in FIG.

  In the correspondence table 150 of the specific example shown here, a range of “7 ≦ σ <10” is described as a reference range of the standard deviation σ. Further, a range of “10 ≦ σ <15” is described as a range in which the standard deviation σ is slightly larger than the reference range, and a range of “15 ≦ σ” is described as a range in which the standard deviation σ is larger than the reference range. I have. Further, a range of “4 ≦ σ <7” is described as a range in which the standard deviation σ is slightly smaller than the reference range, and a range of “σ <4” is described as a range in which the standard deviation σ is smaller than the reference range. I have.

  Also, values “−8”, “−4”, “0”, “+4”, “+8” are shown as increase / decrease values of the removal amount, and “−6” is used as an adjustment value of the pale color corresponding parameter. , “−3”, “0”, “+3”, and “+6”.

  Here, specific examples are shown for the case where the standard deviation σ = 12 and the case where the standard deviation σ = 3.

  FIG. 14 is a diagram showing a specific example when the standard deviation σ = 12.

  If the standard deviation σ = 12, it corresponds to the second column from the right of the correspondence table shown in FIG. 13, so the threshold value of the ground color is changed to “+4” on the low luminance side with respect to the threshold value 103 of the initial setting. . This change amount is one third of the width of the standard deviation σ = 12 shown in the figure. As a result of this change, almost all the pixels belonging to the ground color peak 101 are reset, while the light color pixel It can be seen that a portion 107 remains in the pixels belonging to the peak 102 of FIG. For the pixels belonging to the remaining portion 107, the amount of increase in the density is increased by “+3”, and the appearance of the entire light-colored portion is maintained.

  FIG. 15 is a diagram illustrating a specific example where the standard deviation σ = 3.

  If the standard deviation σ = 3, it corresponds to the fifth column from the right of the correspondence table shown in FIG. You. Although this change amount is twice or more the width of the standard deviation σ = 3 shown in the figure, it can be seen that all the pixels belonging to the ground color peak 101 are reset. On the other hand, almost all portions 108 remain in the pixels belonging to the peak 102 of the light-colored pixels, and the amount of increase in the density for this portion 108 is “−6”, and the density hardly increases. As a result, the appearance of the light color portion is maintained.

  In the above-described embodiment, a multifunction peripheral has been exemplified as an embodiment of the image forming apparatus of the present invention. However, the image forming apparatus of the present invention may be a printer or a copier.

  Further, in the embodiment described above, the image forming unit that forms a color image by a so-called electrophotographic method using toner is exemplified. However, the image forming unit according to the present invention is an image forming unit such as an inkjet type. Or an image forming unit dedicated to monochrome.

  Further, in the above-described embodiment, the variation in sensitivity in the image reading unit 10 is confirmed by the standard deviation of the ground color. Alternatively, a method may be employed in which a standard material having uniform uniformity is prepared in addition to the manuscript, and sensitivity variations are obtained from variations in the read values of the standard material.

  Further, in the above-described embodiment, the removal amount of the ground color and the parameter corresponding to the pale color are adjusted stepwise with respect to the change in the variation in the sensitivity in the image reading unit 10. Alternatively, the removal amount of the ground color and the parameter corresponding to the pale color may be continuously adjusted in response to the variation in the sensitivity variation. Further, the ground color removing unit according to the present invention may be one that adjusts only the ground color removal amount in response to a change in sensitivity variation.

DESCRIPTION OF SYMBOLS 1 ... Multifunction machine 10 ... Image reading part 21 ... Control part 22 ... User interface (UI) part 23 ... Image processing part 30 ... Image forming part 110 ... Analysis part 120 ... Adjustment unit, 130 ... Processing unit

Claims (3)

A ground color removing unit that removes the image of the document read by the document reader that reads the image of the document as a ground color to a higher density color as the variation in sensitivity in the document reader is larger;
Among the colors in the image of the document remaining after the ground color is removed by the ground color removing unit, the density of the color existing in the density area adjacent to the density area of the ground color is determined by the sensitivity in the document reader. A concentration increasing portion that increases greatly as the variation in
An image output unit that outputs an image of the document whose ground color has been removed by the ground color removal unit and the density of which has been increased by the density increasing unit ;
An image processing apparatus comprising: A document reader for reading the image of the document,
A ground color removing unit that removes the image of the original read by the original reader as a ground color to a higher density color as the variation in sensitivity in the original reader is larger;
Among the colors in the image of the document remaining after the ground color is removed by the ground color removing unit, the density of the color existing in the density area adjacent to the density area of the ground color is determined by the sensitivity in the document reader. A concentration increasing portion that increases greatly as the variation in
An image forming unit that forms an image of the document on which a background color has been removed by the background color removing unit and the density of which has been increased in the density increasing unit on a recording medium;
An image forming apparatus comprising: Embedded in an information processing apparatus,
A ground color removing unit that removes the image of the document read by the document reader that reads the image of the document as a ground color to a higher density color as the variation in sensitivity in the document reader is larger;
Among the colors in the image of the document remaining after the ground color is removed by the ground color removing unit, the density of the color existing in the density area adjacent to the density area of the ground color is determined by the sensitivity in the document reader. Concentration increasing portion, which increases greatly as the variation in
An image output unit that outputs an image of the document whose ground color has been removed by the ground color removal unit and the density of which has been increased by the density increasing unit ;
An image processing program that is operated as an image processing apparatus provided with:

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