JPH0545940B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method of cutting out a peel-off film to match the document or leaving only the necessary image part in order to mask unnecessary parts of a separation film in color printing. The present invention relates to a cutting device that exposes a silver halide film to create a mask.

[Prior art]

A color scanner is used when creating color separation plates (plate making) for color printing. A color scanner photoelectrically reads a color original, separates the image signal into color signals for each color component of printing, and exposes a color separation plate film accordingly. Color separation plates are created by developing this film.

Although color scanners can specify a color separation range, the specified range is limited to a rectangular range. Therefore, instead of using the entire image of a color original for printing, if you want to print only people or products, such as flyers, with a white background or a predetermined color, use a color separation plate. When producing a positive master plate for printing plate printing, it is necessary to mask unnecessary parts (background) in the color separation plate. To create a positive master plate for printing plate printing from color separation plates,
Since a photographic method such as contact printing is used, the printing light can be masked by partially blocking the color separation plate. As a light shielding member for this purpose, there is a peel-off film in which a red sheet (the same color as the printing light) is pasted on a transparent sheet.

Then, place this peel-off film on the color separation plate, cut out the red sheet according to the outline of the area required for printing, peel off the red sheet from the transparent sheet, overlap it on the color separation plate, and print. By creating a positive master plate for printing, unnecessary areas can be shielded from light with a red sheet.

[Problem that the invention seeks to solve]

Traditionally, this cutting was done by specialized experts, but as it required extreme precision, it was difficult to obtain a satisfactory result.
The problem was that it took time.

This invention was made to deal with the above-mentioned situation, and in order to accurately mask the unnecessary parts of the color separation image, only the necessary parts of the image are detected,
It is an object of the present invention to provide a cutting device that automatically creates a mask member according to a detection result.

[Means for solving problems]

The clipping device according to the present invention includes an input section that reads image information of a color separation plate, a clipping processing section that detects an area of a predetermined pattern including a designated point in the read image, and It is equipped with an output section consisting of an X-Y plotter for cutting out a peel-off film or an exposure machine for exposing a silver halide film.

[Effect]

According to the clipping device according to the present invention, by simply specifying one or several points within the necessary portion, an image of only the necessary portion (filled image) or the outline of the necessary portion can be detected, and automatically The area to be masked can be determined and a mask member created.

〔Example〕

Hereinafter, one embodiment of a cutting device according to the present invention will be described with reference to the drawings. This clipping device mainly includes an input section 10, a clipping processing section 12, and a data processing section 1.
4. Consists of an output section 16, in addition to which a digitizer 20 is connected to the clipping processing section 12, a display section (color monitor) 22, and an external storage device (hard disk device) 24 connected to the data processing section 12.
Equipped with.

The input unit 10 optically reads the color separation plate and obtains the image signal of the original, and consists of a flat scanner used in facsimile machines, a television camera, etc., and has a resolution of 10 lines/image.
Preferably, it is about mm. The figure shows an example of a flat scanner. An image sensor such as a CCD as a reading section is provided within the main body. The color separation plates are aligned by register pins 30 and fixed on the document table.

Image signals for each color component (Y, M, C, K) from the input section 10 are supplied to the clipping processing section 12 . The cutout processing unit 12 detects an image of a desired pattern (hereinafter referred to as a fill-in image) including a point designated by a pointer (not shown) (connected to the display unit 22) from the image signal for each color component. Detection processing for filled images includes detection using color difference keys,
There is detection using luminance keying. Color difference key processing is to detect a filled-in image based on the difference in color between images, while luminance key processing is to detect a filled-in image based on the difference in brightness between images. When an XY plotter having a cutter attached to the pen tip is employed as the output unit 16, edge processing is performed from this filled-in image to extract outline information. Furthermore, after this, the contour information is smoothed and vector-converted in the data processing section 14. What is vector transformation?
Since the fill-in image information is raster information, it is necessary to convert it to vector information.

On the other hand, when an exposure machine that directly exposes the silver halide film leaving only necessary parts is used as the output unit 16, the filled-in image data detected by the color difference key and the luminance key is used as is.

Furthermore, if the cutout is too large during actual printing, unnecessary lines such as white lines will be visible on the outside of the image, so the data processing unit 14 corrects the outline to be a little more inside than it actually is. Note that the data after these modifications and conversions are saved in the external storage device 24.

In this embodiment, a digitizer 20 is further provided. If the fill-in image cannot be automatically detected in the cut-out process 12, the operator traces the outline of the desired image on the color separation plate using a digitizer 20, and manually inputs the fill-in image information to the cut-out process section 12.

A display unit 22 is connected to the clipping processing unit 12,
The filled-in image information detected by the cutout processing section 12 or input from the digitizer 20 is displayed and confirmed. Further, selection of a desired image is also performed by specifying one or several points on this screen with a pointer.

The output data of the data processing section 14 is supplied to the output section 16, and the peel-off film is cut out.
A silver halide film is exposed. That is, as mentioned above, attach a cutter (a cutter that can cut only the upper red film of the peel-off film) to the pen tip of the X-Y plotter, place the peel-off film on this, move the cutter according to the outline, and cut out the red film. Cut out the film. Alternatively, you can invert the fill signal obtained from the fill process to create a drum,
Alternatively, a film on a flat surface is exposed, and parts other than the desired image area are exposed. By developing this film, a mask film with black areas other than the desired image area can be obtained. Here, it is necessary that the color separation plate placed in the input unit 10 and the film placed in the digitizer 20 are aligned.

Peel-off film cut out in this way,
Layer the exposed mask film on the color separation plate,
By creating a positive master plate for printing plate printing,
A version of only the desired portion of the image is obtained.

As explained above, according to this embodiment, the required pattern area can be automatically detected from the image information of the color separation plate, and the peel-off film can be cut out or the silver halide film can be exposed accordingly. Unwanted parts of the plate can be accurately masked.

Note that this invention is not limited to the embodiments described above, and can be modified in various ways. For example, the details of each part are merely examples, and other similar circuit configurations may be used.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a cutting device that can automatically create a mask member that can accurately block unnecessary portions of a color separation plate.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of a cutting device according to the present invention. 10... Input section, 12... Cutting processing section, 14
...Data processing section, 16...Output section, 20...Digitizer, 22...Display section, 24...External storage device.

Claims (1)

[Scope of Claims] 1. In a cutting device for creating a mask that is superimposed on the color separation plate and blocks unnecessary patterns when a printing plate is created from the color separation plate, means for reading image information of the color separation plate; means for displaying the read image information; means for specifying a point within a desired pattern in the displayed image; and detecting an area of the desired pattern including the specified point from the read image information. What is claimed is: 1. A cutting device comprising: a means for outputting a mask according to a detected area;