JPH0638629B2 - Image processing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image processing method for converting an image.

[Conventional example]

Conventionally, as one of the image processing methods of this type, an electronic plate making technique in the printing industry and a professional lab technique applying computer photographic image processing in the photographic laboratory industry are known.

For example, when a reproduced image is obtained by photoelectrically scanning an image original with a high-precision scanner such as a layout scanner or a laser color printer, a signal processing unit is provided in the middle of the process to correct the density expression (γ correction) for the input density signal. ), Gradation setting,
The following effects are obtained by performing processing such as color correction and cutout composition.

Fading restoration of color film Adjusting highlights and shade gradations, exaggeration of color expression Relief of equipment failure, shooting mistake, development mistake, etc. Expressing creative images, expanding the image area and creating new designs.

Conventionally, this kind of special effect includes mosaic processing arranged regularly, posterization processing for changing the γ curve into an unrealistic one, solarization processing, and the like. However, there is a problem in that it is rare to express a creative image, expand the image area, and create a new design with such processing. As another method, for example, DPB7000 (Quantel Corporation), Artron 2000 (Artronix Corporation), Response 300
(Citex Co., Ltd.) has cut-out composition and painting functions, but in this case the creator uses a coordinate pointing device such as a tablet digitizer to add to the original image, which requires a considerable amount of time. However, there is a drawback that the sense of the creator is reflected in the reproduced image.

An example will be described below in which mosaic processing with a size of 5 in the x direction and 5 in the y direction is performed. Digital image (m,
The n) th pixel information is expressed as a (m, n). Here, the pixel information a (m, n) indicates a digital count value obtained by A / D converting the density signal or the luminance signal of the film document. Then, assuming that the pixel information of the original image is a (m, n) and the pixel information of the processed reproduced image is a '(m, n), the following relational expression is obtained in the mosaic processing.

a '(5m-i, 5n-j) = a (5m-3, 5n-
3) where i = 0, 1, 2, 3, 4 j = 0, 1, 2, 3,
4, m, n are natural numbers. In the above relational expression, the central value of the pixel block of 5 × 5 is the representative value, and that value is also substituted for the other pixels in the block, but the representative value is 5 × 5. Any value or average value may be used as long as it is a pixel block.

In this way, conventional mosaic processing has the drawbacks that the arrangement of rectangular blocks is too regular, and the original image information is greatly lost because all pixels in the block have the same value. In order to achieve this, an improved processing method has been earnestly desired.

〔Purpose〕

An object of the present invention is to provide an image processing method capable of eliminating the above-mentioned drawbacks of the conventional example and expressing a creative image.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing an example of the flow of a density signal when the present invention is applied to a color scanner. An input signal obtained by photoelectrically scanning a film document loaded on the input drum 1 is converted into a density signal by the logarithmic conversion circuit 2 and then input to the input signal processing unit 4 via the AD converter 3. , The density value of each film is converted according to the type of the film, and the density value is converted so as to have a fixed relationship with the exposure amount of the film. This is because the film characteristic curve differs depending on the negative film, the positive film, and the reversal film, and in the case of a color image, especially in the negative film, the R, G, and B colors. After that, the image is input to the image processing unit 5, which is the heart of the system, and digital image processing is performed. After this, the image processing unit 5
The density signal output from the D / A converter 7 is processed by the output signal processing unit 6 to be converted into a laser light amount control signal.
After that, the laser beam input to the modulator 8 and output from the light source 9 is modulated, and the output drum 10 reproduces a desired image.

FIG. 2 is a block diagram showing a part of the image processing unit 5 in more detail. CPU11 is a control processor,
It has all the real rights of the image processing unit 5, and controls the image processing based on the control program stored in the CPU memory 12. The parameter controller 13 includes a computing unit 14, a parameter memory 15, and a parameter setting I / O.
Control 16 to initialize, set, and compare parameters necessary for processing. Processor 18 and CPU1
1 is an image controller 17 via the CPU BUS
The processor 18 is operated by a command from the CPU 11. The processor 18 is a core portion of the image processing unit 5, and is an arbitrary image memory (1) 20-selected according to a command from the CPU 11.
(8) Image data is received from 27 or the image data I / O 36, and the calculated result is sent to any of the selected image memories 20 to 27 or the image data I / O 36. In addition, a flag map memory 1 which is a dedicated memory for carrying a carrier to a necessary address by calculation
It is also possible to output to 9. Image memories 20-27 are C
Since it is connected to both the PU BUS and the VIDEO BUS, the image memory 20
It is possible to read / write from 27 to 27 and perform real-time operation between arbitrary memories. A high-speed RAM called a backup table (1) 28 to (8) 35 is connected to the exit of the image memory. This RAM is 256x
With 8-bit structure, 8 RAM address lines (0-255 addresses can be specified = 0-255 gray levels can be specified) are directly connected to the output of each image memory, and 8 data lines are connected to VIDEO BUS. Has been done.
The contents of RAM can be freely read and written by the CPU 11. The image data I / O 36 is an image input / output interface, and the input signal processing unit 4 in FIG. 1 is connected to the image data I / O 36. An output signal processing unit 6 is also connected to the data I / O 36 and outputs image data to the output signal processing unit 6.

FIG. 3 shows a flow chart of the digital image processing method performed by the image processing unit 5, and FIG. 4 is a graph showing the states of the backup table (1) 28 to (8) 35, and the horizontal axis shows the input floor. And the vertical axis shows the output gradation. Fourth
In the figure- (a), the standard state is shown, and the value 0 is written in the address 0, the value 1 is written in the address 1, ... The value 255 is written in the address 255, and the input and output contents are the same. If a value of 0 is written in address 0, 255, 1 in address 254, ..., 255, it means that the input-output is an image in which the density data is inverted.
It is shown in FIG.

The digital image processing method performed by the image processing unit 5 will be described below in detail with reference to the flow chart of FIG.
Here, the density data of the digital image is represented in the form of ai (m, n) for the sake of explanation. However, i is R, G, and B, and indicates R component image data, G component image data, and B component image data of the original image, respectively. In addition, each pixel has 8 bits for each component, that is, data capable of expressing 256 gradations. The value of the data with the highest density (darkest data) is set to 0, and the value of the data with the lowest density (the brightest data) It is set to 255.

Step 1 Description of S1 The processor 18 is instructed by the input signal processing unit 4 to transfer the R
The component image data is stored in the image memory (1) 20. Subsequently, the G component image data and the B component image data of the original image are stored in the image memories (2) 21 and (3) 22, respectively. At this time, the Lucky Up Table (1) 28-
(8) 35 is the standard state of FIG.

Step 2 Explanation of S2 Image memory (1) 20 by the function of the processor 18
The image data of is substituted into the image memory (4) 23.
At this time, the contents of the look-up table (1) 28 are in the standard state as shown in FIG. 4 (a), so the contents of the image memory (1) 20 are copied to the image memory (4) 23 as they are. Similarly, image memory (2) 2
1. The image data of the image memory (3) 22 are respectively stored in the image memory (5) 24 and the image memory (6) 25.
To copy.

Step 3 Explanation of S3 Here, the parameters necessary for the calculation are set. In the present embodiment, the size of the pixel block mo is input by keying in a keyboard (not shown) or the like from the parameter setting I / O 16.
Input xno and its contents (for example, the data conversion shape in the pixel block). The content is specified by 0 and 1 in the mo × no matrix, the operation is performed at 1 and the representative value is substituted and the data is rewritten, but at 0, the data value is the same as the original image. 5 (a) and 5 (b) show the contents of pixel blocks in the case of 5 × 5 and 9 × 9 as examples. In this example, the creator inputs the data by the parameter setting I / O 16, but if the information is stored in the parameter memory 15 in advance, it can be automated without the operator having to input the parameter data. Yes.

Depending on the pixel block size mo × no and the pixel data size M × N set here, the number of pixel blocks P1 for one operation, which is a parameter required for the following operation, and the number of times P2 of repeating the same To calculate. The parameters P1 and P2 were obtained by the following arithmetic expressions.

P1 = (M / mo) × (N / no) / 4 P2 = SQR (mo × no) where P1 and P2 are integers.

Further, a control parameter IP1 used for controlling the following calculation
Is initialized. Specifically, when IP1 = 1, the following processing is performed for the image memory (1) 20 when IP1 = 1, and for the image memories (2) 21, (3) 22 when IP1 = 2 and IP1 = 3, respectively. To process.

Step 4 Explanation of S4 An image is formed in the image memory (7) 26 in which the shape (consisting of 1, 0) of the pixel block set in Step 3 is a periodic pattern in both the x and y directions. Introduction The image memory (7) 26 by the function of the processor 18
Is cleared (all are set to 0), and the data of the shape stored in the parameter memory 15 is read out and periodically written in the image memory (7) 26. If the pixel block data is represented by b (m, n) and the pixel data created in the image memory (7) 26 is represented by a7 (m, n), the relationship between the two is as follows.

Becomes

It is also possible to store the image composed of the above-mentioned periodic pixel block in an external memory (not shown), read it out after setting the parameters of step 3, and store it in the image memory (7) 26.

Step 5 Description of S5 IP1 is a control parameter designated by the image memory to be processed. When IP1 = 1, the result output is the image memory (1) 20 and the reference image memory required for the operation is the image memory (4 ) 23. Also I
When P1 = 2, they are the image memories (2) 21 and (5) 24, respectively, and when IP1 = 3, they are the image memories (3) 22 and (6) 25. Then, when IP1 = 4, the calculation in the main image processing unit is ended and the process proceeds to the next sequence.

Step 6 Description of S6 IP2 = 1, which is the initial setting of control parameters used in the following calculations. This control parameter is step 1
The count is incremented by 1 and step 12 compares it with the number of times P1 of calculation of the pixel block calculated in step 3 to control the pixel block.

Step 7 Description of S7 A random number sequence used in the following processing is set. By setting the random number sequence at this point, the generation of random numbers in the process performed on the image memories (1) 20 to (3) 22 becomes the same value, and the designated position of the block processing unit is the same as that of the 3 image memories. To

Step 8 Explanation of S8 A basic shift amount is calculated by generating a random number. Here, a value between 0 and mo is generated for the x direction, and a value between 0 and no is generated for the y direction. Here, the deviation amounts are represented as ms and ns, respectively.

Step 9 Explanation of S9 The data of the image memory designated by the control parameter IP1 is copied to the image memory (8) 27 by the function of the processor 18. That is, the data in the image memory (4) 23 is copied when IP1 = 1, the data in the image memory (5) 24 is copied when IP1 = 2, and the data in the image memory (6) 25 is copied when IP1 = 3. To do. Then, the block processing unit is designated in the image memory (8) 27 by using random numbers as follows. A random number Rx is generated in the range of 0 to M / mo in the x direction (which is converted to an integer by cutting it) and 0 to N / in the y direction.
A random number Ry is generated within the range of no (cut into integers by cutting). From the random numbers and the shift amounts ms and ns obtained in the previous step 8, (Rx of the image memory (8) 27
Xmo-ms, Ryxno-ns) is set to the upper left, and the rectangular portion in the x direction mo and the y direction no is rewritten with the data of the representative value in the rectangle. Here, the representative value is the data value at the center of the rectangle. That is, when the data of the image memory (8) 27 is generally expressed as a (m, n), four points a (Rx × mo−
ms, Ry × no-ns), a (Rx × mo-ms + m
o-1, Ry × no-ns), a (Rx × mo-ms +
mo-1, Ryxno-ns + no-1), a (Rxx
mo-ms, Ry × no-ns + no-1) The data value of is a calculation that satisfies the following relational expression.

However, 0≤i≤mo-1, 0≤j≤no-1 As described above, the operation of rewriting the data of the pixel block portion by generating the random number and rewriting the data in the pixel block portion by the value is repeated P1 times the number of pixel blocks. Return.

Step 10 Explanation of S10 The processor 18 is used to align the image of the pixel block created in the image memory (8) 27 with the image block of "0, 1" created in the image memory (7) 26. ) 26 is shifted. The shift operation is a process of moving the designated image memory in parallel in the x direction or the y direction and substituting the one line pixel row at the end of the moving direction into the one line pixel row on the opposite side. That is, the processor 18 that performs the +1 shift processing in the x direction
If the input image (original image) to a and the output image (resulting image) are a '(m, n), then the following relationships exist.

a '(m, n) = a (m-1, n) where a' (0, n)
= A (M, n) x direction -1 shift operation is a '(m, n) = a (m + 1,
n) However, a ′ (M, n) = a (0, n) y direction + 1 shift operation is a ′ (m, n) = a (m, n−
1) However, a '(m, 0) = a (m, N) y direction -1 shift operation is a' (m, n) = a (m, n +)
1) However, a '(m, N) = a (m, 0). Image memory using this shift operation (7)
26 images are shifted by −ms in the x direction and −ns in the y direction. After clearing the flag map memory 19, the flag map memory 19 is processed by the processor 18 to set a flag at the pixel position "1" of the image memory (7) 26. Next, the flag map memory 19
The data of only the pixel position with the flag is assigned from the image memory (4) 23 to the image memory (1) 20. Naturally, the processing from the image memory (4) 23 to the image memory (1) 20 is performed by the control parameter IP1 = 1.
When IP1 = 2 and 3, processing is performed from the image memory (5) 24 to the image memory (2) 21 and from the image memory (6) 25 to the image memory (3) 22, respectively. After that, the image in the image memory (7) 26 is again subjected to the shift operation to display the image in the x direction for ms and the y direction for n
s Move and keep the original positional relationship.

Steps 11 and 12 Explanation of S11 and S12 Step 11 counts up the control parameter IP2 and branches at step 12 according to the parameter. When IP2 is larger than P2, the process proceeds to the next step 13 which is equal to P2. If it is small, repeat from step 8. That is, step 8 to step 1
By repeating P2 times up to 2 times, only the shape of the "1" part of the shape b (m, n) of the pixel block set in step 3 is randomly rewritten with the representative value of P1 × P2 pixel block numbers. .

Step 13 Explanation of S13 The control parameter IP1 is counted up, and the process proceeds to step 5.

The digital image processing as described above is performed, and the result is that the R, G, and B component image data are stored in the image memory (1) 20, the image memory (2) 21, and the image memory (3) 22, respectively. When reproducing an image, R, G, B from the image memory (1) 20, the image memory (2) 21, and the image memory (3) 22.
The component image is read out and output from the image data I / O 36 to the output signal processing unit.

As described above, according to this embodiment, the size of the pixel block and the conversion of the pixel data in the pixel block can be arbitrarily designated, so that the following (1) to (5) can be performed.

(1) Compared with the conventional regular rectangular mosaic, the degree of discreteness is high and the rectangle is inconspicuous, so that different creative images can be expressed.

(2) Since the pixels in the block do not all have the same value, the original image information is small and the goodness of the original image can be retained.

(3) Images of various expressions can be created by the same processing method depending on the shape of the pixel block so as to give an impression similar to oil painting or dot painting.

(4) It is possible to provide a new image, which is not provided by the "dark room processing" that has been performed by the conventional silver halide system or the electronic plate making of the printing system, and it is possible to increase the degree of freedom in drawing.

(5) Since the image processing process can be unmanned, it can be expected to spread in a laboratory.

In this embodiment, the image processing unit is used as the image processing unit, but it goes without saying that the same effect can be obtained by using a general-purpose computer such as a minicomputer.

Further, in the present embodiment, the image is input from the film, but even if the image data is directly captured from the subject from a still video camera, a video camera, etc., the image is recorded via a recording medium such as a magnetic floppy disk, a magnetic tape, an optical disk or a bubble memory. The same effect can be obtained by inputting data.

〔effect〕

As described above, according to the present invention, input image data is stored in the first storage means and the second storage means, and any point in the image data stored in the first storage means is stored. The data is read, the image data stored in the second storage means is rewritten with the data of a plurality of points forming a predetermined pattern using the data of the arbitrary points read from the first storage means, and the second data is stored. Since the image data stored in the storage unit is output, the atmosphere of the original image can be freely changed while suppressing the loss of the original image information, and a natural-looking creative image can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of the flow of a density signal when the present invention is applied to a color scanner, FIG. 2 is a block diagram showing in more detail a part of the image processing section of FIG. 1, and FIG. The figure which shows the flow chart of an Example, FIG. 4 (a),
(B) is a diagram showing the state of the look-up table used in the explanation of FIG. 3, and FIGS. 5 (a) and 5 (b) are diagrams showing an example of parameter setting performed in the flow chart of FIG. is there. 1 ... Input drum, 2 ... Logarithmic conversion circuit, 3 ... AD converter, 4 ... Input signal processing unit, 5 ... Image processing unit, 6 ... Output signal processing unit, 7 ... DA converter, 8 ... Modulator, 9 ... Laser light source, 10 ... Output drum, 11 ... Control processor, 12 ... CPU memory, 13 ... Parameter controller, 14 ... Arithmetic unit, 15 ... Parameter memory, 16 ...... Parameter setting I / O, 17 ...... Image controller, 18 ...... Processor, 19 ...... Frag map memory, 20 to 27 ...... Image memory, 28 to 35 ...... Lookup table, 36 ...... For image data I / O

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical indication location H04N 1/387 4226-5C (72) Inventor Kazunori Urushihara 770 Shimonoge, Takatsu-ku, Kawasaki-shi, Kanagawa Canon Inc. Inside the Tamagawa Plant (72) Inventor Susumu Matsumura 770 Shimonoge, Takatsu-ku, Kawasaki City, Kanagawa Prefecture Canon Inc. Inside the Tamagawa Plant (72) Hiroshi Omura 770, Shimonoge, Takatsu-ku, Kawasaki City, Kanagawa Inside the Tamagawa Plant, Canon Inc. ( 56) References JP-A-59-41968 (JP, A)

Claims (1)

[Claims] 1. A step of storing input image data in a first storage means and a second storage means, and a step of reading out data at an arbitrary point in the image data stored in the first storage means. And rewriting the image data stored in the second storage means with data of a plurality of points forming a predetermined pattern using the data of the arbitrary points read from the first storage means, And a step of outputting the image data stored in the second storage means.