JPH03245147A - Printing simulation device - Google Patents

Abstract

PURPOSE:To allow the rapid and accurate checking of whether color resolving conditions are good or not by providing a color resolving condition setting means, 1st memory means, comparing means, specific color generating means, 2nd memory means, and color monitor means. CONSTITUTION:Specific conditions are set as the color resolving conditions in a color computing means 2 which makes color correction of the image data read by an input means 1 according to the conditions thereof. This image data is stored in a 1st memory means FM11. The different color resolving conditions are set in the color computing means 2 which make color correction of the image data and stores the data in another 1st memory means FM12. Two sets of the image data are read out by corresponding the same to every picture element from the 1st memory means FM11, FM12. The picture element data is written as it is into the 2nd memory means FM2 when the absolute value of the difference between both sets of the read out picture element data and the specific color data is formed and is written therein when the above-mentioned value is larger. The above-mentioned processing is executed with all of picture element data and the region changed in color with a change in the color resolving conditions is discriminated from the other region and is displayed by a display color for identification on the display screen of the color monitor means 9. Whether the color resolving conditions are good or not is rapidly and accurately judged in this way.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention simulates a printed image on the display screen of a color monitor in order to check various color separation conditions when color printing a color original. The present invention relates to a printing simulation device, and particularly to a printing simulation device that is used in combination with a color scanner and is convenient for simple proofreading.

(Prior Art and its Section B) When printing in color, a color original is first separated into colors using a color scanner. There, the read image data is subjected to color correction according to various color separation conditions (for example, tone correction made by correcting the gradation curve), then color separated, and color separation is performed according to the color separation signal. Create a version. Next, a printing plate for proof printing is made using the obtained color separation plate, and this printing plate for proof printing is applied to a proofing machine to perform a proof printing. At this time, the color separation conditions of the scanner (color correction amount ) is appropriate, and if the color tone of the proof print is not desirable, change the color separation conditions, perform color correction again, and perform the color separation plate and proof print again.

The above-mentioned process is repeated until a proof of the desired color tone is obtained, and once the desired proof is obtained, a practical color separation plate is prepared according to the separation conditions, and then printed by a printing machine.

By the way, since such proof printing requires a considerable amount of time, cost, and labor, printing simulation devices using color monitors have been developed in recent years. According to this printing simulation device, the finished state of the printed matter is simulated on the color monitor without performing proof printing, so the number of times proof printing is required can be reduced.

The following is a typical conventional example of this type of printing simulation apparatus, and the problems thereof will be explained below.

60-232542''' In this first conventional example, the display screen of a color monitor is divided into two at the center, and one area displays the original image of the color document as it is, while the other area displays the image corrected according to the color separation conditions. The system is configured to display images.An operator visually observes both images, confirms the effect of color correction, and determines whether the color separation conditions are good or bad.

However, by visually comparing both images in this way, you can check the effect of color correction. Because it requires skill, it is not possible to accurately check whether the color separation conditions are good or not, and in particular, for example, for a color original with an orange or apple pattern displayed in the background of a person, it is difficult to print only the orange in a more orange-like tone. When you want to change the color separation conditions subtly, such as when you want to print in harmony with the tones of a person, orange, and apple, and in a well-balanced state as a whole, you can check the areas that have changed. It becomes difficult.

Furthermore, if there is a slight color change in an area that is originally not desired to be changed, there is a risk that this may be overlooked.

Z-31569 In this second conventional example, image data read by a color scanner is color-corrected and then displayed on a color monitor, and the highlight level of each pixel of the image data is compared with a predetermined highlight cent level. Then, the area above the highlight cent level is flashed on the display screen of the color monitor, thereby allowing the operator to confirm the quality of the highlight set.

However, according to this conventional example, since flashing is performed on a color monitor where the display screen itself flickers, it is easy to overlook these areas when the area above the highlight level is small or when flashing an area with very poor gradation. As a result, highly accurate confirmation work cannot be performed, and in addition, this conventional device only compares image data with a reference level, and when color correction is performed using different color separation conditions many times, the previous By comparing the image data obtained under the color separation conditions and the image data obtained under the current color separation conditions, it is not possible to recognize areas where the hue or the like has changed between the two data.

(Purpose) The present invention has been made to solve the various drawbacks of the above-mentioned conventional techniques, and an object thereof is to provide a printing simulation device that can quickly and accurately confirm the acceptability of a plurality of different color separation conditions. do.

(Means for Solving the Problems) The technical means of the present invention for solving the above problems is as follows: (1) A color original is read by an input means, the read image data is color-corrected by a color calculation means, and then the color correction is performed. In a print simulation device that is connected to a color scanner that supplies subsequent image data to an output means, sets color separation conditions for the scanner, and displays on a monitor based on the corrected image data, the color calculation means performs color separation. a condition setting means for providing a condition; a first switching means interposed between the color calculation means and the output means to switch the output path of the color calculation means between the output means side and the printing simulation side; a first memory means for individually storing each image data corrected by the means under a plurality of different color separation conditions via the first switching means for each different color separation condition; and from the first memory means. a comparison means for comparing the two read image data pixel by pixel; a specific color generation means for generating specific color data of a display color that is distinguishable from a normally used display color; , if the data of corresponding pixels of the two image data are almost the same, write the data of one pixel as is to the corresponding address, and if the data of the corresponding pixels of the two image data are different, write the data of one pixel to the corresponding address. a second memory means for writing and storing specific color data generated by the specific color generating means; and selectively reading image data written in the first and second memory means and displaying the image. It is characterized by comprising a color monitor means, and.

(2) Furthermore, in the present invention, the color monitor means:
It is preferable to read the respective image data from the second memory means and the first memory means and display those images in a divided manner.

(3) Further, in the present invention, between the human power means and the color calculation means, there is provided a third memory means for storing the thinned image data read by the input means, and a third memory means for storing the thinned image data read by the input means; A second switching means is provided for switching the image data outputted from the input means and the image data output from the input means and inputting the same to the color calculation means, and at the time of printing simulation, the second switching means is switched to the third memory means side. Preferably, the image data stored in the third memory means is read out and used.

(4) Furthermore, in the present invention, the first switching means and the first
It is preferable that a converting means for converting subtractive color image data to additive color method image data is provided between the first memory means and the first memory means to store the additive color method image data.

(5) Furthermore, in the present invention, subtractive color image data output from the color calculation means is stored in the first memory means, and the first memory means, the second memory means, and the color monitor means are connected to each other. A converting means for converting subtractive color image data into additive color image data may be provided between the converting means and an image based on the additive color method image data from the converting means may be displayed on the color monitor means. .

(Operation) First, specific conditions are set as color separation conditions in the color calculation means, and image data read by the input means is color corrected according to the conditions. The corrected image data is then stored in the first memory means via the first switching means. At this time, the image after color correction is displayed on the color monitor means.

Next, color separation conditions different from the above conditions are set for the color calculation means. The image data is color corrected according to the changed conditions, and the corrected image data is stored in another first memory means. At this time as well, the image after color correction is displayed on the color monitor means.

Then, the two image data are read out in association with each pixel from the first memory means, and the difference between the read data of both pixels, for example, the brightness level, is taken, and for example, if the absolute value of this difference is less than or equal to a preset value, In this case, it is assumed that the data of both pixels are almost the same, and the data of one pixel is written as is into the corresponding address of the second memory means.

In addition, if the absolute value of the difference is larger than the set value, the data of both pixels are considered to be different, and the pixel data to be compared is invalidated, and instead, extremely high chroma that is not found in the normal printed image is used. The color and color removal utilizes specific color data of the identification display color consisting of the specific display color of the state,
This specific color data is written into the corresponding address of the second memory means. Then, the above processing is performed on all the pixel data, and then an image based on the pixel data written in the second memory means is displayed on the color monitor means.

In this way, on the display screen of the color monitor means, the area whose color has changed due to the change in the color separation conditions is distinguished from other areas and displayed in an identification display color. Therefore, the operator can easily check the area where the color has changed, and as a result, it is possible to accurately judge whether the color separation conditions are good or bad.

(Example) An example of the present invention will be described below with reference to the drawings. 1st
The figure is a block diagram showing a printing simulation device and a color scanner connected to it.

The color scanner has a human power section (input means) L and a color calculation port I! as surrounded by a dashed line. ) (color calculation means) 2 and output section (
Output means) 3 is the main component.

The print simulation run device includes a thinning circuit 4, a frame memory (memory means) FMI L FMI2, FM2,
FM3, selector (switching means) SL1 to SL5, conversion circuit (conversion means) 5, comparison section (comparison means) 6, set value generation section 7, specific color generation section (specific color generation means) 8, color CR
T-display (color monitor means) 9, control section 10,
It consists of a console (condition setting means) 1).

The human power section 1 of the color scanner uses, for example, a drum-shaped input scanner, and while a cylinder loaded with a color original is rotated 62 times around its axis, the color original is picked up by a pick-up unit using the three primary colors of the additive color method. It is read as B, G, and R image data, logarithmically converted, and output. However, a flat input scanner may be used as the human power section l.

The color calculation circuit 2 is a gradation conversion circuit including a Lufukuassobuttable RAM, USM (Unsharp
masking) circuit, color correction circuit, etc.
Performs various calculation processes such as color correction (color correction),
The processed data is converted into 8-bit data for each of Y, M, and C1K and output. This color calculation circuit is known from the above-mentioned Japanese Unexamined Patent Publication No. 1-131569, and is commonly used.

The above calculation processing by the color calculation circuit 2 is performed based on the setting of color separation conditions through manual operation by the operator. Also, some of the condition settings can be automatically set.

The output unit 3 is an output scanner consisting of a halftone signal generation circuit, a laser light source, an acousto-optic modulator that modulates a laser beam to generate an exposure beam, and the like.
generate an exposure beam corresponding to each image data of C,
A recording operation is performed by irradiating this onto the surface of a photosensitive material for recording.

Note that the image data after color correction may be provided to a layout system (image editing device), and this layout system is also included in the output means in the present invention, and a memory such as a disk that stores the image data is also an output means. shall be included in.

The thinning circuit 4 of the simulation evening converts the B, G, and H image data (for example, 8-bit data) output from the input section 1 to a color CRT.
This is a circuit that thins out each pixel to match the number of pixels on one screen of the display 9. The thinning rate and how to thin out are set by the control unit 10.

The third frame memory (third memory means) 1M3 is composed of, for example, a 512x512 pixel image memory, and divides the B, G, and R image data thinned out by the thinning circuit 4 into B, G, and R. The data is stored in each storage area, and the control unit 1 is also
Image data is read out using a control signal given from 0.

The second selector (second switching means) SL2 switches the input path of image data to the color calculation circuit 2. That is, when the selector SL2 selects the input path a shown in the figure,
The B, G, and R image data read by the input section 1 is applied as is to the color calculation circuit 2. Also, selector SL
2 selects the input path of b, frame memory F
The image data once stored in M3 is given to the color calculation circuit 2. The switching operation of selector SL2 is controlled by control section 10.

The first selector (first switching means) SLI switches the output path of image data from the color calculation circuit 2. That is, when the selector SLI selects the output path a, image data from the color calculation circuit 2 is provided to the output section 3. Further, when the selector SLI selects the output path b, the image data from the color calculation circuit 2 is given to the conversion circuit (conversion means) 5.

Switching of the selector SLI is performed by a control signal from the control section 10.

The conversion circuit 5 includes a conversion table for converting subtractive color image data to additive color image data, and converts the density data of each color Y, M, C, sent from the color calculation circuit 2 into B, Convert to luminance data of G and R colors.

The converted luminance data is selectively stored in the first frame memories (first memory means) FMII and FM12 via the third selector SL3 for each of B, G, and R. This selection is made in order to compare and consider two corrected images with different color separation conditions, and is made by a control signal from the control unit 10. That is, the image data for which color calculations were performed under the first set color separation conditions is stored in one frame memory FMII, and the image data for which color calculations were performed under the next set color separation conditions are stored in the other frame memory FMII.
12. If the color separation conditions are set three or more times, this is dealt with by rewriting the image data already written in the first frame memories FMII and FM12 with new image data. Incidentally, a large number of frame memories may be added so that even if the color separation conditions are set three times or more, they can all be stored. Further, it is desirable that the first frame memories FMII and FM12 and the second frame memory FM2, which will be described later, have the same capacity.

The comparison unit 6 compares the absolute values of the luminance data read from the two frame memories FMII and FMII for each corresponding pixel, and the difference between the two luminance data is preset in the set value generation unit 7. For example, if the set values are equal, a "H" signal is sent to the output terminal, otherwise, a "L" signal is sent to the output terminal.
The set value of the set value generator 7 can be changed to any value fIt, including O.

The fourth selector SL4 is switched according to the output of the comparator 6 as follows. When the output of the comparator 6 is "H", the luminance data read from one first frame memory FMII is directly transferred to the second frame memory F.
M2, and when the output of the comparing unit 6 is “L”, the specific color data output from the specific color generating unit 8 is output to the second frame memory FM2.
Since the data write address of M2 is made to correspond to the read address of the second frame memory FMII, 2M12 by the control unit IO, the second frame memory FM2
If the luminance data stored in the frame memories FMII and 2M12 are the same, that luminance is written to the corresponding address as it is, and if the two luminance data are different, a specific color from the specific color generating section 8 is written. Data will be written to the corresponding address.

The specific color generating section 8 is a circuit that generates specific color data that is sent to the human power section 1 and corresponds to a color that can be distinguished from the display color that is normally used. As a distinguishable color, for example, a particularly highly saturated color or a color omission (no color is emitted and displayed), etc. are assumed.

The fifth selector SL5 selects the color CRT display 9.
This selects the image to be displayed above, and in this example,
Each image stored in the frame memories FM2, FMII, and 2M12 can be selected. Selector SL5
The selection switching is also performed by a control signal from the control section 10.

The control unit 10 switches the selectors SLI, SL2, etc., and switches the frame memories FMII, 2M12, FM2, etc.
It is used to control reading and writing of the FM3, and to cause the print simulation apparatus to perform simulation operations based on instructions manually input from the console 1) or automatically.

This control section 10 and the comparison section 6 can be configured by one CPU.

The console (condition setting means) 1) is a part where the switching of the selector SL5, the change of the color separation conditions of the color calculation circuit 2, etc. can be manually input. An operation panel (keyboard) can also be used instead of the console 1). Note that although the control unit 10 and the console 1) are provided on the printing simulation device side in the drawing, they are part of the color scanner I! They also share Noh.

Next, the operation for setting the color scanner to optimal color separation conditions using the printing simulation apparatus will be explained.

First, a predetermined thinning rate is set in the thinning circuit 4 using a control signal from the control section 10 . In this state, a briscan is performed, and the B, G, and R image data obtained from the manual section 1 is thinned out at a predetermined thinning rate and written into the third frame memory FM3.

By writing the image data in the frame memory FM3 in this manner, and reading it out at a timely command from the control unit 10, subsequent image data can be supplied to the circuit 62 without having to scan the same document many times. .

Also, selectors SLI and SL2 are switched to the b side, and selector SL3 is switched to the a side. Then, image data is read from the frame memory FM3 based on a read command from the control section 10, and outputted to the conversion circuit 5 through the color calculation circuit 2.

As a result, image data subjected to color calculation under the initial color separation conditions is obtained and stored in the first frame memory FMII. At this time, the image can be displayed on the color CRT display 9 by switching the fifth selector SL5 to the a side. Next, the color separation conditions of the color calculation circuit 2 are changed to obtain color-separated image data in the same manner as described above, and this is transferred to the third
frame memory FM12 via the b side of selector SL3.
Store in. In this way, image data with different color calculation results can be stored in the first frame memories FMII and 2M12.

Two frame memories FMI 1. The image data stored in the FMI 2 is sequentially read out pixel by pixel according to commands from the control unit 10 and compared.

Then, if the absolute value of the difference between both data is less than the value preset in the set value generating section 7, one image data is written as it is to the corresponding address of the second frame memory FM2, and conversely, if the difference is larger, For example, specific color data is written into the second frame memory FM2.

This operation is repeated for one frame, and data for one image is stored in the second frame memory FM2.

At this time, when the selector SL5 is switched to the C side, an image based on the data stored in the second frame memory FM2 is displayed on the color CRT display 9, and when the selector SL5 is switched to the a side, the image based on the data stored in the first frame memory FMII is displayed. When the images based on the stored image data are further switched to the b side, the images based on the image data stored in the first frame memory FM12 are displayed. The operator visually checks the displayed image on the color CRT display 9 while sequentially switching the selector SL5 from the console 1) to detect subtle changes in ff! I can recognize it.

Note that during this confirmation work, if the two corrected images to be compared and the identified image after comparison are displayed in three parts, the confirmation can be made even easier. In this case, a divided display processing circuit may be used in place of the selector SL5.

The most preferable color separation conditions are selected through this Wi confirmation process. If a desirable color separation result cannot be obtained by changing the color separation condition settings one to two times, the above operation is repeated by changing the color separation conditions to a different one. Color C
Change the display on RT Display 9 to f! If the optimum color separation conditions are obtained by checking the color separation conditions, the color separation conditions are selected.

This selection is instructed by the operator from the console 1). The optimum color separation conditions selected here are set in the color calculation circuit 2 by the control section 10.

When this setting is completed, the control unit 10 selects the selector S.
Both LI and SL2 are switched to the a side.

Then, the input unit 1 performs a main scan of the color original,
The image data read at that time is transferred to the second selector SL.
2 to the color calculation circuit 2, where it is masked (color correction) based on the preset color separation conditions mentioned above.
The output unit 3 is processed through the first selector SLI.
The output unit 3 exposes and records the duplicate image.

Although the illustrated embodiment is as described above, the present invention can be modified in various ways as described below.

In the above embodiment, the Y, M, C, -B, G, R conversion circuit 5 is provided in the front stage of the first frame memories FMIL, FM12, but this is eliminated and the fifth selector SL5 and color CRT are provided. It can also be provided between the display 9 and the display 9. In addition, in the above embodiment, three
frame memories FM2, FMI 1. Although FMI 2 is used, a single memory having an extremely large memory capacity may be used instead.

Further, in the embodiment described above, two scans, briscan and main scan, are performed to record a copy under optimal color separation conditions, but it is also possible to perform one scan.

In other words, a separate large-capacity frame memory is used, and the image data obtained in one scan is written into this memory, and this is used both when selecting the optimal color separation conditions and when sending it to the output section for copy recording. It should be used for.

(Effects of the Invention) As explained above, according to the present invention, areas whose color has changed due to a change in color separation conditions are distinguished from areas where the color has not changed and are displayed in a unique identification display color. The operator can easily check visually. Therefore, an error in setting the color separation conditions does not occur, and the optimum color separation conditions can be set quickly and accurately.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the overall configuration of a printing simulation apparatus according to the present invention. DESCRIPTION OF SYMBOLS 1... Input part (input means), 2... Color calculation circuit (color calculation means), 3... Output part (output means), 5... Conversion circuit (conversion means), 6... Comparison section (comparison means), 7
...Set value generation section, 8.Specific color generation section (specific color generation means), 9..Color CRT display (color monitor means), 10..Control section, 1)..Console ( condition setting means), SLl...first selector (
switching means), SL2... second selector (switching means)
, FMI 1. FMI2...first frame memory (memory means), FM2...second frame memory (memory means), FM3...third frame memory (memory means).

Claims (5)

[Claims] (1) Connected to a color scanner that reads a color original with an input means, performs color correction on the read image data with a color calculation means, and then supplies the corrected image data to an output means;
A printing simulation apparatus that sets color separation conditions for the scanner and displays on a monitor based on the corrected image data, comprising: condition setting means for providing color separation conditions to the color calculation means; the color calculation means and output means. and a first switching means inserted between the color calculating means and switching the output path of the color calculating means between the output means side and the printing simulation side, and each image corrected by the color calculating means under a plurality of different color separation conditions. a first memory means for individually storing data for each different color separation condition via the first switching means; and a comparison means for comparing two image data read out from the first memory means pixel by pixel. , when the data of corresponding pixels of the two image data are almost the same based on the comparison result of the comparison means and the specific color generation means that generates specific color data of a display color that is distinguishable from the normally used display color. writes the data of one pixel as it is to the corresponding address, and if the data of the corresponding pixel of the two image data is different, writes and stores the specific color data generated by the specific color generating means to the corresponding address. A printing simulation apparatus comprising: a second memory means; and a color monitor means for selectively reading image data written in the first and second memory means and displaying the image. (2) The printing simulation apparatus according to claim (1), wherein the color monitor means reads out respective image data from the second memory means and the first memory means and displays the images in a divided manner. Printing simulation device. (3) In the printing simulation apparatus according to claim (1), a third memory means for storing thinned-out image data read by the input means is provided between the input means and the color calculation means; A second switching means is provided for switching the image data read from the memory means of No. 3 and the image data output from the input means and inputting the same to the color calculation means, and during printing simulation, the second switching means is switched to the third memory. A printing simulation apparatus characterized in that the image data stored in the third memory means is read out and used by switching to the third memory means side. (4) In the printing simulation apparatus according to claim (1), a conversion means for converting subtractive color method image data into additive color method image data is provided between the first switching means and the first memory means. 1. A printing simulation apparatus, wherein the first memory means stores additive color image data. (5) In the printing simulation apparatus according to claim (1), the first memory means stores subtractive color image data output from the color calculation means, and the first memory means and the second memory means store subtractive color image data output from the color calculation means. Conversion means for converting subtractive image data into additive color image data is provided between the memory means and the color monitor means, and the color monitor means converts an image based on the additive color image data from the conversion means. A printing simulation device characterized by displaying on the top.