JPH0743762B2 - Gradation / color correction device for composite images - Google Patents

Description

The present invention relates to a gradation / color correction device for a composite image, which can perform optimum gradation correction on a human image and a computer graphics image. is there.

[Conventional technology]

As a photo card, such as an employee card, use color photographic paper as a display sheet, insert it into a plastic frame sheet, stack a plastic core sheet underneath it, and overlay transparent plastic oversheets on top and bottom A four-layer structure is known by thermocompression bonding.

The display sheet, as shown in FIG.
, A computer graphics image (hereinafter referred to as a CG image) 3 and a character 4 are electrically image-combined, and the composite image is printed on a color photographic paper via a CRT.
As for a person image, a TV camera directly captures an image of a person, or a negative film or a print photograph is captured by the TV camera and input to a video printer. CG images are created using a digitizer or the like, and these are input to a video printer via floppies or the like.

The person image and the CG image are subjected to gradation correction by a gradation correction circuit in order to improve color balance, and then image combination is performed. A look-up table memory is used as the gradation correction circuit, and the image signal is converted by the table data for each color set in the look-up table memory.

[Problems to be solved by the invention]

The above-mentioned conventional tone correction uses the same table data for both the human image and the CG image, so the color balance is good for the human image, but for the CG image, the color balance is good. There was a problem that the balance deteriorated.

In addition, when a person is directly shot by a TV camera, the finish of the person image changes due to differences in lighting in the studio. Therefore, in order to improve the finish of the person image, the table data is modified, but this modification causes the finish of the CG image to be different for each studio.

[Object of the Invention]

The present invention is capable of performing optimum gradation correction on both a human image and a CG image, and
An object of the present invention is to provide a color correction device.

[Means for solving problems]

In order to achieve the above object, the present invention provides a gradation correction lookup table memory, an image type instructing unit for instructing an image type, and gradation correction table data for these images for each image type. For storing the gradation correction table data in the gradation correction look-up table memory based on the instruction signal from the instructing means, the color correction look-up table memory, and the color correction look-up table memory. Table data creation for creating color correction table data by multiplying the coefficient data of the matrix calculation formula for each image type by the corresponding coefficient data and the image level value based on the instruction signal from the instructing means And a means for writing the color correction table data from the table data creating means in the color correction lookup table memory. It is obtained by an adder for adding the data output from the color correction look-up table memory.

[Action]

From the prepared personal image data and CG image data, select the one that corresponds to the type of image to be processed, and these are the gradation correction look-up table memory and color correction look-up table. Set to memory. Since the gradation correction and the color correction are performed with the table data that matches the characteristics of the image, both the human image and the CG image can be optimally finished. Further, at the time of color correction, since a product of a color correction coefficient and an image level value is written as table data for each image type in the color correction lookup table memory, the color correction lookup table is used. By adding the image data from the memory with the adder, color correction can be performed at high speed without individually performing matrix calculation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

〔Example〕

FIG. 1 shows a color video printer embodying the present invention. A person 10 is directly photographed by a color TV camera 12 in a studio illuminated by an illumination light source 11. Also,
Instead of the direct shooting, a color negative film, a color reversal film, a color print photograph or the like of a person may be used, and these may be picked up by the color TV camera 12.
Further, instead of the color TV camera 12, a black and white TV camera may be used, and red, green, and blue color filters may be sequentially inserted to perform three-color plane sequential imaging.

The color TV camera 12 captures an image of the person 10 and outputs red, green, and blue person image signals and synchronization signals. The timing circuit 13 outputs a conversion timing signal of the A / D converter 14 and an address signal for writing data in the frame memory 15 based on the synchronization signal. The A / D converter 14
Converts each color person image signal digitally for each color and then sends it to the frame memory 16 to write the image signal of each color to a predetermined address.

A CG image created by a digitizer or the like is stored in the floppy 17, and is read by a diskette device (not shown) when the CG image is input and input to the controller 18.

The person image signal of each color read from the frame memory 15 and the CG image signal input from the flop 17 are respectively stored in a look-up table memory 20 for performing gradation correction for each color via a bus line 19. Sent. The look-up table memory 20 is written with one selected from a plurality of table data prepared in advance, and the type of the lighting and the subject (direct photographing, print photograph, negative film, positive film, CG image, etc.). ). For example, in the case of direct shooting, gradation correction is performed so that the image signal of each color has a designated value (the same value for each color) when the gray plate is directly shot. Further, in the color negative film, a color negative film obtained by photographing a gray plate is used, and the color negative film is imaged by a color TV camera, and the image signal of each color is corrected so as to have a designated value. Further, since the CG image does not change when the image is input, linear table data that is a straight line or a broken line is used.

The color correction circuit 21 uses the matrix calculation formula (1) on the human image and the CG image to perform color correction for increasing the saturation.

Note that R, G, B are image signals after color correction, R ₀ , G ₀ , B ₀ are image signals before color correction, and a1 to a3, b1 to b3, c1 to c3 are coefficients. .

The color correction circuit 21 includes nine look-up table memories for storing, as table data, a product obtained by multiplying an image level value by a coefficient in order to perform matrix calculation at high speed.
22 and three adders 23 for adding the data output from them.

The gradation correction and the matrix calculation are effective for a human image, but they are unnatural for a CG image, so it is better not to perform these image processes. However, in order to make the signal processing system one line, both the person image and the CG image are sent to the lookup table memory 20 and the color correction circuit 21, and instead, for the CG image,
The table data is written so that gradation correction and matrix calculation are not substantially performed.

That is, the color correction circuit 21 uses, for example, the following matrix calculation formula (2) for a person image, and table data for executing this is written in the lookup table memory 22. Further, the matrix calculation formula (3) is used for the CG image, and table data for executing this is written in the lookup table memory 22.

The color-corrected image data of the person image and the CG image are sent to one of the positive look-up table memory 24a and the negative look-up table memory 24b, where gradation correction is performed for each color. It These look-up table memories 24a and 24b are for correcting the change in the type of color photographic paper and the characteristics of the developing solution, and as described in the look-up table memory 20, the specified values (for all three colors) Data that corrects so that it becomes gray on the printed photo when actually printed with the same value) is written.

The image-processed person image and the CG image are sent to the frame memory 25 via the bus line 19, and are written and combined in the designated areas. This area corresponds to the position where the image is fitted and can be designated by the keyboard 48. The address of the frame memory 25 is designated by the controller 18 when writing data, and is read by the CRT controller 27 when printing. This image signal is converted into an analog signal by the D / A converter 28 that operates with the timing signal from the CRT controller 27. The selector 29 is switched by the controller 18, selectively takes out the three-color image signal, sends this to the driver 30, drives the exposure black and white CRT 31, and
A monochrome image in which each color image is represented by brightness is sequentially displayed. The order of this display can be arbitrarily determined.

The black and white image displayed on the black and white CRT 31 is the printing lens 33.
Thus, an image is formed on the color photographic paper 34 at a desired magnification. A red filter 35, a green filter 36, a blue filter 37, and a shutter 38 are arranged between the printing lens 33 and the color printing paper 34. These color filters 35 to 37 are sequentially inserted into the printing optical path 40, and convert the monochrome image displayed on the monochrome CRT 31 into a monochrome image.

The color printing paper 34 is wound in a roll shape, and is drawn out by a pair of drawing rollers 41 and set at an exposure position formed behind the mask 42. At this exposure position, the color photographic printing paper 34 that has been sequentially exposed in the three-color plane is sent to the development processing section 44 by the feed roller 43 and is temporarily stocked. The cutter 45 operates when a predetermined number of frames have been exposed, and cuts the exposed color photographic paper 34 into short pieces. The short color photographic printing paper 34 is passed through the processing tanks of the developing processing section 44 to be subjected to photoprocessing, and finally cut by the cutter 46 frame by frame, and then discharged to the tray 47.

The controller 18 is composed of a computer, and controls each unit in accordance with a preset sequence according to an instruction from the keyboard 48. Also, the controller 18
The frame memory 15 according to the instructions from the keyboard 48.
It is possible to change the area to be read from the frame memory.
You can change the size of the person image that fits in 25. Memory 49 is RAM and ROM as is well known.
And stores programs and table data.

FIG. 2 shows data writing to the look-up table memory 20. Since the finish differs depending on the type of subject and the imaging state (for example, lighting), if different gradation correction is performed depending on the type of image,
The overall finish is good. Therefore, in the memory 49, for example, CG image table data 50 and person image table data 51 are prepared. The person image table data 51 includes direct shooting table data 51a and 51b, negative table data 51c, and print photograph table data 51d.
There is. These table data 50 and 51 are stored in the keyboard 4
It is selected by 8 and written in the look-up table memory 20. Here, since the lighting and the like of the direct-shooting table data changes depending on the studio in which the image is taken, table data suitable for each studio is created and stored in the memory 49.

FIG. 3 shows an example of table data written in the lookup table memory 20. In this embodiment, the CG table data 50 is common to all three colors, and
Since it is linear data with a slope of 45 degrees, it is output without any gradation correction. On the other hand, the person image table data 51a has a different curved shape for each color.

FIG. 4 shows an example of table data stored in the look-up table memory 24a. The look-up table memory 24a stores table data for performing correction according to characteristics of the photographic processing system (type of color photographic paper 34, type of developing solution, etc.) and positive / negative inversion. In this embodiment, the same table data 53 is used for all three colors, but in reality it is slightly different. In the negative look-up table memory 24b, table data for performing correction based on the characteristics of the photographic processing system is written. ROM is used for these look-up table memories 24a, 24b, and when the type of color photographic paper or the type of developing solution used changes,
Replace the corresponding table data with the written ROM.

When the two types of table data are combined, the table data as shown in FIG. 5 is obtained, and gradation correction depending on the type of subject and gradation correction depending on the type of processing system are performed. When the lookup table memory 24b is selected, the inverted table data shown in FIG. 5 is used.

FIG. 6 shows writing of the table memory to the look-up table memory 22 of the color correction circuit. Memory 49
Includes the coefficient data 55 of the matrix calculation formula for CG images.
And the coefficient data 56 of the matrix calculation formula for the human image are set. Any one coefficient is selected in accordance with the type of image to be color-corrected, and each coefficient is multiplied by each image level value to create table data, which is stored in the look-up table memory 22 of the color correction circuit 21. Write.

Next, the operation of the above embodiment will be described. For example, in the studio No. 1, when the person is directly shot, the keyboard 48 is operated to instruct that the studio No. 1 is the direct shot. The controller 18 selects the direct-shooting table data 51a from the memory 49 and writes it in the lookup table memory 20. In addition, the controller 18 is a memory
Select the human image coefficient data 56 from 49, create the human image table data by calculation, and use this to create a color correction circuit.
Write to look-up table memory 22 of 21.

The person 10 illuminated by the illumination light source 11 is captured by the color TV camera 12, and the person image is converted into a three-color image signal. The person image signal of each color is A / D controlled by the timing circuit 13.
A / D conversion is performed by the converter 14. The person image signal of each color converted into the digital signal is written to the address of the frame memory 15 designated by the timing circuit 13.

The controller 18 writes the frame memory 15
In order to extract only the upper half of the person image, the person image signal stored in a specific area of the frame memory 15 is sequentially read out for each pixel. The read person image signal of each color is
It is sent to the look-up table memory 20 via the bus line 19. Since the direct-shooting table data 51a of the person image shown in FIG. 3 is written in the lookup table memory 20, the person image signal of each color is tone-corrected by the table data 51a.

The person image signal of each color whose gradation has been corrected by the look-up table memory 20 is sent to the color correction circuit 21. The color correction circuit 21 adds the data read from the look-up table memory 22 by the adder 23 to perform matrix calculation (2) to perform color correction.

The color-corrected person image signal of each color is sent to the positive look-up table memory 24a, and the gradation is corrected by the table data shown in FIG. The gradation-corrected person image signal of each color is sent to the frame memory 25 provided for each color via the bus line 19 and written in a predetermined area in which the person image is to be fitted.

When inputting a CG image, operate the keyboard 48 to
Instruct the controller 18 to input a CG image. The controller 18 writes the CG table data 50 into the lookup table memory 20, and writes the table data created using the CG coefficient data 55 into the lookup table memory 22. After this writing, the CG image stored in the floppy 17 is read and input to the controller 18. This CG image signal is sent to the look-up table memory 20 via the bus line 19 to be subjected to gradation conversion, and then the color correction circuit 21 performs color correction by the matrix calculation formula (3). However, since γ is 1 in the CG image table data and the matrix arithmetic expression (3) is “0” except for the diagonal term, gradation conversion and color correction are not substantially performed.

The CG image signal output from the color correction circuit 21 is sent to the look-up table memory 24a and subjected to gradation correction by the photo processing system, and then transferred to a predetermined area of the frame memory 25 via the bus line 19. Written. Characters such as names are input from the keyboard 48 and the like, subjected to the same image processing as CG images, and then written in the frame memory 25.

When the keyboard 48 is operated to give a print instruction, the CRT controller 27 operates to read the image signal written in the frame memory 25, convert it into an analog signal by the D / A converter 28, and then send it to the selector 29. The selector 29 selects, for example, a red image signal in response to a signal from the controller 18, sends the red image signal to the driver 30, and displays a black-and-white image representing the red image in luminance on the black-and-white CRT 31.

Since the reading of the frame memory 25 is repeated, a black-and-white image is continuously displayed on the black-and-white CRT 31, and a red filter 35 is inserted into the printing optical path 40 together with the black-and-white image to convert the black-and-white image into a red image. Since the shutter 38 opens during this time, the red image is printed on the color photographic paper 34 by the printing lens 33. When the monochrome CRT 31 displays a monochrome image for the number of frames corresponding to the red exposure amount, the shutter 38 closes and the red exposure ends.

When the red exposure is completed, the selector 29 takes out a green image signal, so that a monochrome image in which the green image is represented by luminance is displayed on the monochrome CRT 31. At the same time, the red filter 35 is retracted from the burning optical path 40, and the green filter 36 is inserted into the burning optical path 40 instead, so that the black and white image displayed on the black and white CRT 31 is converted into a green image. The green image is printed on the color photographic printing paper 34 for a plurality of frames while the shutter 38 is open for a time corresponding to the green exposure amount. By the same procedure, the blue image is printed on the color printing paper 34.

When a composite image in which a person image, a CG image, and characters are combined is printed on the color photographic paper 34 by three-color sequential exposure, the color photographic paper 34 is transported by one frame. Then, when a predetermined number of frames are exposed, the cutter 45 operates to separate the exposed portion into a short length. This short color photographic printing paper passes through each processing tank and is subjected to photographic processing, and is cut into one frame by a cutter 46 to produce a print photograph as shown in FIG.

When direct shooting is performed in the studio No. 2, if this is indicated by the keyboard 48, the direct shooting table data 51b is selected and written in the lookup table memory 20. Further, when a color negative film is imaged, the negative table data 51c is selected and written in the lookup table memory 20. Also, in this case, since the positive / negative inversion is necessary, the lookup table memory
24b is selected.

Since the CG image is stored in the frame memory 25, when using the same one as an employee card,
A person image and characters may be input and written in a predetermined area.

FIG. 7 shows another embodiment of table data used for tone correction of a CG image. In this embodiment, as the linear table data, broken line table data 60 having a steep slope from a high signal level is used, and is written in the lookup table memory 20 immediately before the input of the CG image.

In the above embodiment, a color monitor is provided when it is necessary to check the composite image. This color monitor is connected to the frame memory 25 via an inversion circuit and displays a positive color image. Further, it is preferable to provide a color and density correction key on the keyboard 48 so that the correction amount can be input while observing the color monitor to perform color and density correction. When this correction amount is input, the table data of each color is shifted according to the correction amount and then written in the lookup table memory 20.

Further, in the above-described embodiment, the image composition is performed after the gradation correction, but each image is written in a predetermined area of the frame memory 25, the image composition is performed, and then the area is designated to read out the image. On the other hand, gradation correction or color correction may be performed.

〔The invention's effect〕

As described in detail above, according to the present invention, different table data is set in the gradation correction circuit for the gradation correction of the person image and the gradation correction of the CG image.
Optimal tone correction can be performed for both images. In particular, even if the type of subject (direct shot, negative film, print photograph, etc.) changes, the finish of the CG image is not affected, and the same finish can always be maintained. Further, the color correction circuit is composed of a color correction look-up table memory and an adder, and the color correction look-up table memory uses coefficient data of a matrix calculation formula stored for each type of image, Since the product of this coefficient data and the image level value is written as table data,
In the matrix calculation, it is not necessary to calculate individual image data and coefficient data each time, and color correction can be performed at high speed. In addition, since color correction requires different coefficient data depending on the type of image, it is possible to finish both the person image and the CG image to be combined into optimum colors. In addition, since a person image and a CG image are image-processed using a single image processing system including a gradation correction lookup table memory, a color correction lookup table memory, and an adder, the device is simplified. , The cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a color video printer embodying the present invention. FIG. 2 is an explanatory diagram showing writing of gradation correction table data used for correcting differences in subjects. FIG. 3 is a graph showing an example of table data for gradation correction. FIG. 4 is a graph showing an example of gradation correction table data used for correcting changes in the photographic processing system. FIG. 5 is a graph showing the result of combining two types of gradation correction table data. FIG. 6 is an explanatory diagram showing writing of table data used for matrix calculation. FIG. 7 is a graph showing another embodiment of linear table data used for gradation correction of CG images. FIG. 8 is a plan view showing a print photograph on which a composite image is printed. 10 …… Person 11 …… Illumination light source 20 …… Lookup table memory for gradation correction 21 …… Color correction circuit 31 …… B & W CRT 34 …… Color photographic paper.

Claims (3)

[Claims] 1. A gradation / color correction device for a composite image, which performs gradation / color correction on each image before or after combining a person image and a computer graphics (CG) image, for gradation correction. A look-up table memory, an image type instructing means for instructing an image type, a means for storing gradation correction table data for these images according to the image type, and an instruction signal from the instructing means. Means for writing corresponding gradation correction table data in the gradation correction look-up table memory, color correction look-up table memory, and coefficient data of a matrix calculation formula for color correction are stored for each type of image. Means for generating color correction table data by multiplying the corresponding coefficient data and the image level value based on the instruction signal from the instructing means. Means for writing the color correction table data from the table data creating means into the color correction lookup table memory, and an adder for adding the data output from the color correction lookup table memory. A composite image gradation / color correction device characterized by the above. 2. The gradation / color correction apparatus for a composite image according to claim 1, wherein the gradation correction table data for the CG image is linear table data. 3. The person image is a direct-shot person image, a negative image, and a print photograph image in a plurality of studios having different lighting conditions, and gradation correction table data and a color correction matrix are provided for each of these images. Claim 1 or 2 characterized by storing coefficient data of an arithmetic expression.
A gradation / color correction device for a composite image according to the item.