JPH04208939A - Printing simulation system - Google Patents

Abstract

PURPOSE:To allow the exact setting of color separation conditions without overlap of correction functions by providing a circuit for correcting the color separation conditions in only the simulation procession without providing this circuit in a color scanner. CONSTITUTION:An operator sets the separation magnification of a color original 12 by a separation magnification control circuit 26 and reads color images signals R, G, B by a reading head 14. These signals are once stored in a memory 46. The simulation processor 24 occasionally reads the color image signals out of the memory 46 at need and displays in simulation the images of the color tone gradations approximate to the color tone gradations of printed matter on a color monitor 44 via a printing approximation circuit 33. The area, size, etc., for displaying on the monitor 44 are instructed when the operator operates the processor 24. The operator corrects the magnification by the circuit 26 and sets the adequate separation conditions by an edge stressing circuit 28, etc., while viewing the monitor 44.

Description

Detailed Description of the Invention [Industrial Application Field 1] The present invention adjusts color separation conditions (various correction amounts) when color printing a color original, and substantially performs plate inspection (setting separation conditions, The present invention relates to a printing simulation system that displays images of color printed matter in simulation on the screen of a color monitor and collects patterns, etc. for inspection.

[Prior art] When printing in color, a color document is read with a color scanner, and the color signals of the read image are R (red), G (green), and B.
After correcting various color separation conditions of (blue), print image signals for printing Y (yellow), M (magenta), C (cyan)
, K (black), and color separation plates are created according to the print image signal.

The color separation plates are pasted in predetermined positions together with films containing characters, figures, etc., and then compiled. A printing plate for proof printing is made from the obtained collection plate, and this printing plate for proof printing is run through a proof printing machine to perform proof printing.

Determine whether the color separation conditions of the scanner are appropriate based on the color tone of the proof print, and if the color tone of the proof print is not the desired color tone, change the amount of correction, perform color separation again, create color separation plates, and print the proof print again. Once a proof print with a desired color tone is obtained, a working plate is made from the color separation plate, and the actual printing is performed by printing it on a printing machine (practical machine).

By the way, since it takes a lot of time, money, and effort to peel off such collections and proofs, printing simulation devices that use computer-based image processing devices and color monitors have been developed in recent years, and they can be used to print printed materials. It is now possible to assemble and check the finished version while checking the finished state on a color monitor.

A conventional print simulation apparatus inputs a print image signal after various color separation conditions such as color tone and gradation have been corrected using a color scanner, and displays a simulation of the finished state of the printed material based on the input print image signal. Here, the printing simulation device is also provided with a function of correcting the color separation conditions provided in the color scanner, and corrects the color separation conditions such as tone and gradation while performing simulation.

With this, it is possible to collect images, characters, figures, etc., while electronically inspecting the plates, and finally output them on film page by page using a color scanner.

[Problems to be Solved by the Invention] However, in such a conventional example, since the same color separation condition correction circuit is provided in both the color scanner and the simulation device, there is redundancy and waste in terms of circuitry. , Since the correction functions are also duplicated, the correction work is complicated. In other words, even if the color scanner operator sets the color separation conditions such as gradation, tone, and even sharpness on the color scanner based on intuition and experience, the simulation device operator who received the color separation image data will need to monitor the color monitor again. Because the color separation conditions were changed in the simulation device while looking at the results, the work became redundant and the division of responsibility for color separation quality was unclear. In addition, the simulation device requires a memory to store input data, but in the conventional example, the print image signals of the four colors Y, M, C, and K for exposure of the color separation plate are transmitted to the color scanner. Since the data is supplied to the simulation device from , four memories were required.

The present invention has been made to address the above-mentioned circumstances, and its purpose is to provide a printing simulation system that has a simple configuration and can output a collection under accurately optimal color separation conditions.

[Means for Solving the Problems] A printing simulation system according to the present invention includes a color scanner that reads color image signals of a color original and exposes a color separation plate, and a color scanner that is connected to this color scanner and that reads color image signals input from the color scanner. After the image signal is subjected to color tone correction, gradation correction, and collection processing, it is converted into an image signal, and based on this image signal, the printed matter is displayed in a simulated manner,
The apparatus includes a simulation processor that converts the image signal into a print image signal and then supplies the image signal to a color scanner to expose the color separation plates.

[Effect]

According to the printing simulation system according to the present invention,
The circuit for correcting the color separation conditions is not provided in the color scanner, but only in the simulation processor, so there is no duplication of correction functions, simplifying the configuration, and making settings on the simulation processor side. ,
Color separation conditions can be set accurately. The simulation processor also receives R, G, and
Since the B color image signal is processed, only three memories are required, which is one less than the conventional method.

[Embodiment] An embodiment of the printing simulation system according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of one embodiment.

A color document 12 placed on a document table (not shown) is read by a reading head 1 consisting of a line of photoelectric conversion elements arranged in a line.
4, image information is read line by line. By moving the reading head 14 or the document 12 in a direction perpendicular to the line direction, one sheet of image information is read. The reading head 14 uses COD as a photoelectric conversion element.
It is equipped with a charge-coupled device (charge-coupled device) and outputs R, G, and B color image signals through red (R), green (G), and blue (B) filters.

The R, G, and B color image signals output from the read head 14 are converted into current/voltage (C/V) converters 16.
The voltage is converted and supplied to the calibration circuit 18, where the level is adjusted. The output signal of the calibration circuit 18 is logarithmically compressed by a logarithmic (LOG) amplifier 20, then supplied to a simulation processor 24 via an A/D converter 22, and then stored in a memory 46.
Read out as needed.

The simulation processor 24 displays a simulation image of printed matter collected based on the image information of the color image signal, and also sets color separation conditions such as gradation and color tone.
The processor 24 that performs the correction includes, for example, a separation magnification control circuit 26, an edge emphasis circuit 28, a color tone correction circuit 30,
gradation correction circuit 32, printing approximation circuit 33, plate collection circuit 34,
It consists of a clipping circuit 36, a combining circuit 38, and a netting circuit 40. Note that each circuit may be realized in software by a computer.

The decomposition magnification control circuit 26 separates the original 12 and the reading head 14 from each other.
By controlling the relative movement speed with respect to the A/D converter 22 and the sampling frequency of the A/D converter 22, the input separation magnification of the color original can be changed, and the magnification can be controlled by affine transformation or the like. The edge emphasis circuit 28 performs Laplacian calculation and the like to improve the sharpness of the picture. The tone correction circuit 30 separates colors from the read color image signal and adjusts the level of each color in order to correct the tone of the printed matter.

The gradation correction circuit 32 corrects the gradation characteristics (highlight set, shadow set, middle separation, highlight separation, shadow separation, etc.) of the color image signals R, G, and B. These circuits 26.28.
30 and 32 are circuits related to correction of color separation conditions.

In this way, since the simulation processor 24 performs various processes on the color image signals R, G, and B in the memory 46, only three memories are required, reducing the number of memories by one compared to the conventional example. I can do it.

The simulation processor 24 processes the image signals R, G, B after various color separation conditions have been adjusted, and the simulated signals R, G, B obtained by converting the image signals in the printing approximation circuit 33. Output. In addition,
Although not shown, the simulation processor 24
The image signal outputted from the image signal is logarithmically expanded through an inverse logarithm (LOG-'') amplifier.

The image signals R, G, and B outputted from the simulation processor 24 are supplied to the dot generator 52 via the pass line 45, where they are converted into print image signals Y, M, C, and K, and the corresponding dot image signals are generated. Each color is supplied to an exposure head 54 consisting of a laser or the like. Exposure head 5
Reference numeral 4 modulates a laser beam in accordance with the dot image signal to expose and scan the color separation plate film 56. By developing this color separation film 56, color separation plates are created.

A memory 46 such as a hard disk or RAM, a line data input section 42, and a character data input section 44 are also connected to the pass line 45. The memory 46 stores color image signals input to the simulation processor 24 and image signals processed by the simulation processor 24. The line data input unit 48 is composed of, for example, a digitizer, and inputs position data indicating where on the color separation plate the image read from each color document is to be placed, or the location of ruled lines or hatching. The character data input section 50 inputs character data constituting a color separation plate together with a picture. Input data from these input units 48 and 50 is input to the simulation processor 24.

A cutout circuit 36 in the simulation processor 24 extracts only a desired picture portion from the color image signal of the color original from the A/D converter 22, as necessary. The synthesis circuit 38 synthesizes a plurality of color image data to create new image data as necessary. The halftone dot circuit 40 also superimposes a halftone pattern on the character data from the character data input section 50 and the graphic data from the line data input section 48, as necessary. The collection circuit 34 converts the color image signal input from the A/D converter 22 based on the position data from the input section 48 and receives an image signal that has been subjected to various processing, and an image signal from the input section 50. character data are laid out on one color separation plate film, and R, G, and B image signals for creating the color separation plate are created. This image signal becomes a Y, M, C, print image signal via the dot generator 52,
The light is supplied to the exposure head 54.

Further, the simulation signals R, G, and B corresponding to the image signals R1G and B supplied from the simulation processor 22 to the dot generator 52 are sent to the printing approximation circuit 33.
, and is supplied to the color monitor 44 via the video RAM 42. As a result, a simulation image of the printed matter is displayed.

Next, a simulation operation of printed matter according to this embodiment will be explained. The operator sets the resolution magnification of the color original 12 using the resolution magnification control circuit 26, and uses the reading head 14 to set the resolution magnification of the color document 12, and then
Read the B color image signal.

The read color image signals are address-controlled by the simulation processor 24 and then stored in the memory 46.

The simulation processor 24 reads the color image signals from the memory 46 as needed, and outputs the color image signals to the printing approximation circuit 33.
An image with a color tone and gradation similar to that of the printed matter is displayed in simulation on the color monitor 44 through the . At this time, the area of the image to be read from the memory 46, the area and size to be displayed on the color monitor 44, etc. are instructed by the operator operating the simulation processor 24.

While viewing the color monitor 44, the operator corrects the magnification using the separation magnification control circuit 26 and sets appropriate separation conditions using the edge emphasis circuit 28, tone correction circuit 30, and gradation correction circuit 32. Furthermore, the color image signal for which the separation conditions have been set can be changed according to the conditions and stored in the memory 46.

As explained above, according to this embodiment, an image that is extremely similar to the actual printed matter is displayed on the color monitor 44, so that the user can set the separation conditions, collect, cut out, combine, and halftone while looking at the color monitor 44. etc. can be done. The final image signals R, G, B processed by the simulation processor 24 are supplied to the dot generator 52,
The signal is converted into a print image signal and exposure of the color separation plate is started.

In this way, the tone of the printed image under each color separation condition can be confirmed on the color monitor 44 without creating a color separation plate, so that it is possible to virtually inspect the plate without actually performing color separation work.

Note that the present invention is not limited to the embodiments described above, and can be implemented with various changes without changing the gist of the invention. For example, the functionality of the simulation processor 24 is not limited to the above example, but may be general (: CE P S (C
color electronic prepress
It also includes the functions possessed by a printing simulation computer called System.

[Effects of the Invention] As explained above, according to the present invention, a color image signal read by a color scanner is supplied to a simulation processor capable of adjusting color separation conditions, and the simulation processor performs various corrections and image processing. After that, the image corresponding to the print image signal used to create the color separation plates is displayed on the color monitor, and the color separation conditions are set.
Since the print image signal is returned to the color scanner and color separation plates are created, the color separation condition setting and correction functions are not duplicated between the color scanner and the simulation processor, simplifying the configuration. It is not necessary to reset the set color separation conditions to the color scanner, and the color separation conditions can be set accurately. Furthermore, since RlG and B color image signals are supplied from the color scanner to the simulation processor, only three memories are required to store the signals, which is one less than in the past. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of a printing simulation system according to the present invention. 14...Reading head, 22...A/D converter, 2
4... Simulation processor, 26... Decomposition magnification control circuit, 28... Edge emphasis circuit, 30...
Color tone correction circuit, 32... Gradation correction circuit, 34... Collection circuit, 36... Cutting circuit, 38... Synthesis circuit,
40... Net cover circuit, 42... Video RAM, 44
...Color monitor, 46...Memory, 48...
・Line data input section, 50...Character data input section,
52... Dot generator, 54... Exposure head. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] A color scanner that reads the color image signals of a color original and exposes a color separation plate; and a color scanner that is connected to the color scanner and processes the color image signals read by the color scanner to produce an image after color tone correction, gradation correction, and plate collection processing. Convert to signal,
A printing simulation system comprising: a simulation processor that displays a printed matter in a simulated manner based on the image signal, converts the image signal into a print image signal, and then supplies the signal to the color scanner to expose color separation plates.