JPH02228653A - Cutting device - Google Patents

Abstract

PURPOSE:To automatically form a mask by displaying an image based on an image signal after color separation and setting a parameter for extraction while viewing a displayed image. CONSTITUTION:The image signal after color separation outputted from a color scanner 2 is supplied to a silhouette image extraction part 6 through an interface unit 4 and the extraction part 6 extracts a silhouette image which is a binary image consisting of a picture element inside a desired pattern or the inverted image of the binary image. At such a time, the silhouette image of the desired pattern is accurately extracted by displaying the image of a color separation plate and specifying optional one point in the desired pattern which should be used for printing and threshold for deciding the difference of lightness or color between the desired pattern and the background while viewing the image. The exposing part of the color scanner 2 is controlled in accordance with the extracted image so as to expose a silver salt film. Thus, the mask for cutting is automatically formed.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention provides a method for creating a positive original plate for printing plate printing from a color separation plate, which is superimposed on the color separation plate and removes parts other than the desired pattern part to be used for printing. The present invention relates to a cutting device for creating a mask that blocks light.

[Prior Art] Color separation plates for color printing are created using a color scanner. The color scanning rod photoelectrically reads a color original, separates the image signal into each color component of printing after various color corrections, 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 all the images in the color manuscript for printing, for example, printing only the products and people, such as flyers, etc.
If there is a request for the background to be white or a predetermined color, when creating a positive master plate for printing from the color separation plate, the unnecessary part (background of the pattern) in the color separation plate is shielded from light. There is a need. As a light-shielding mask, there is a beer-off film in which a red sheet (printed in the same color as the light) is pasted on a transparent sheet and cut out along the outline of the desired pattern.

Conventionally, beer-off film was layered on top of the color separation plate,
Professionally skilled workers cut the peel-off film along the outline of the design, but this cutout required extreme precision, and even though it took time, it was difficult to obtain a satisfactory result. If the outline of the cut-out peel-off film is misaligned with the outline of the pattern, the shape of the pattern may be deformed or the background color may protrude in printed matter, making it unsightly.

[Problem to be solved by the invention 'XJ] This invention was made to deal with the above-mentioned circumstances,
To provide a cutting device which extracts a silhouette image of a desired pattern and automatically creates a mask of the color separation plate according to the silhouette image so as to accurately block unnecessary parts of the color separation plate.

[Means for Solving the Problems] A cutting device according to the present invention includes means for displaying an image based on color-separated image signals output from a color scanner that exposes a color-separated film, and A means for specifying a point within a desired picture area, and comparing the difference between the brightness or color of the specified point and the brightness or color of each point of the displayed image with a predetermined value. The present invention includes means for extracting a silhouette image of a desired pattern, and means for controlling an exposure section of a color scanner based on the extracted silhouette image to create a color separation mask.

[Function] According to the cutting device according to the present invention, an image of a color separation plate is displayed, and while viewing the image, an arbitrary point within a desired pattern to be used for printing, as well as the desired pattern and its background can be selected. By specifying a threshold value for determining the brightness or color difference between You can automatically create a cutout mask by exposing to light.

[Example] Hereinafter, an example of a cutting device according to the present invention will be described with reference to the drawings. FIG. 1 is an overall block diagram. The color-separated image signal output from the color scanner 2 is supplied to the silhouette image extraction section 6 via the interface unit 4. The interface unit 4 may directly connect the color scanner 2 and the silhouette image extraction section 6, or may connect them indirectly via a recording medium such as a floppy disk. The silhouette image extracting unit 6 extracts a binary image consisting of pixels inside a desired pattern, or a silhouette image which is an inverted image of the binary image.

The extracted silhouette image is supplied to the exposure section of the color scanner 2 via the interface unit 4. The exposure section exposes the silver salt film in accordance with this to create a mask.

The configuration of the color scanner 2 is shown in FIG. The color original 12 attached to the reading drum 10
Scanning is performed by the rotation of the drum 10 and the movement of the reading head 14 in the direction of the drum 10, and image information is read. The reading head 14 is equipped with a photomultiplier as a photoelectric conversion element, and the obtained image signal is converted into B, G,
Output as an R image signal.

B, G, and R image signals output from the reading head 14 are subjected to current/voltage conversion by a current/voltage (C/V) converter 16, and are supplied to a calibration circuit 18 for level adjustment. The output signal of the calibration circuit 18 is logarithmically compressed by a logarithmic (LOG) amplifier 20 and then supplied to a color processing circuit 24 .

The color process circuit 24 performs color separation such as color correction and gradation correction for printing, and also includes a masking circuit and undercolor removal (
It consists of a UCR) circuit, a gradation correction circuit, a dot 26 display circuit, etc. The masking circuit performs so-called masking correction and converts the B, G, and R signals into yellow (Y), magenta (M),
Convert to cyan (C) signal. The undercolor removal circuit uses Y and M to print in the four basic colors of printing: Y, M, C, and K (black).

Convert the C signal to Y, M, C, signals. The gradation correction circuit performs gradation correction such as highlight set, shadow set, middle separation, highlight separation, and shadow separation.

These correction amounts, correction amounts, and (separation conditions) can be adjusted as appropriate, thereby making it possible to set color separation conditions that match a desired color tone.

After color correction and correction is performed in the color processing circuit 24, the Y, M, and C image signals are converted into inverse logarithms (LOG −
1) After being logarithmically expanded by the amplifier 28, the signal is supplied to the channel selector 30.

The channel selector 30 selects which color signal to output depending on whether the separation film is exposed for four colors at the same time or for one color at a time. The output of the channel selector 30 is converted into a digital signal by an analog/digital (A/D) converter 32 and then supplied to a dot generator 34. The output signal of the A/D converter 32 is also supplied to the silhouette image extraction section 6 via the interface unit 4. Thereby, there is no need to prepare an image scanner dedicated to reading color separation plates for pattern extraction, so processing time can be shortened and costs can be reduced. Conversely, the silhouette image signal is inputted via the interface unit 4 to one of the output signal lines of the A/D converter 32 (in this case, the K signal line) and inputted to the dot generator 34. Ru.

The dot generator 34 takes into account the magnification of the color separation film 40 with respect to the color original 12 and converts the image signal into a halftone signal for recording as halftone dots. Exposure head 3
6 exposes the color separation film 40 on the recording drum 38 in accordance with the halftone dot signal whose magnification is controlled. By developing this color separation film 40, color separation plates are created. Here, when the silhouette image signal from the interface unit 4 is input to the dot generator 34 and the exposure head 36 exposes the outside of the image on the color separation film (positive film) 40, the color separation film 40 is developed. , a mask is created in which the outside of the image is blackened.

m3 Figures (a) to (e) show the interface unit 4,
The configuration of the silhouette image extraction section 6 is shown.

Here, the color scanner 2 and the silhouette image extraction unit 6
Here is an example where is indirectly connected. Y, M, C, image signals from the A/D converter 32 are sent to the interface CI/
F) 44 to a buffer memory 46, and the output of the buffer memory 46 is co-supplied to a storage device 48 using a storage medium such as a floppy disk.

This floppy disk is played back by the storage device 50 on the side of the silhouette image extraction section, and the image signals of Y, M, and C are sent to the frame memory in the silhouette image extraction section 6 via the buffer memory 52, I/F 54, and selector 56. 58. Here, when the color scanner 2 and the silhouette image extraction section 6 are directly connected, the output of the A/D converter 32 may be directly written to the frame memory 58 via the I/F 44 and the selector 56. The frame memory 58 has Y, M,
Consists of 4 memories each storing image data of 4 versions of C., each memory has a capacity of 1536x1280
(pixels) x 8 (bits) - 1966 (megabytes). The clock frequency during reading is set to approximately 20 M)lz.

The selector 56 has output terminals for each of the four color components connected to these four memories, and outputs the signal from the 1/F 54 from the output terminal of the color designated by the color designation switch 60.

A timing generator 62 is connected to the frame memory 58, and an address signal, a read/write (R/W) mode signal, and a zoom signal are supplied from the timing generator 62 to the frame memory 58.

The zoom signal is a signal for enlarging the image during reading, and the magnification designation switch 64 allows the zoom signal to be set to x1° x3. X6.
It is set to either X12.

Four color image signals of Y, M, and C are simultaneously read out from the frame memory 58, and the color separation circuits 6 and 6 (Fig. 3(b)
)). The color separation circuit 66 specifies color components to be used for silhouette image extraction according to the color tone of the image of the original. This is because the color component with the highest contrast differs depending on the color of the pattern to be extracted. here,
If the detection results for a plurality of colors are to be summed, another color is selected after detection for one color is completed.

The color separation circuit 66 receives a selection signal from a delay circuit 68, a color selection switch 70, a gate 72 for selecting any color of Y, M, and C, a gamma correction circuit 74, and a signal for Y, M, and C. It consists of an adder 76 connected to the line. The gamma correction circuit 74 turns on and off gamma correction according to whether the switch 78 is turned on or off.

As a result, any color signal among Y, M, and C designated and selected by the color selection switch 70 is outputted from the gate 72, and is used for silhouette image extraction. Hereinafter, this selected color signal will be referred to as a chromakey signal.

The adder 76 adds all the color signals of Y, M, and C to obtain a signal corresponding to the luminance when the color selection switch 70 selects all of the colors of Y, M, and C. It is. This signal is also used for silhouette image extraction and is hereinafter referred to as a luminance key signal (LUM). The chroma key signal and luminance key signal are sent to the silhouette image extraction circuit 11, which will be described later.
2. In this way, according to this embodiment, a silhouette image can be extracted according to the difference in color or the difference in brightness. When extracting based on color differences, differences in multiple colors can also be extracted.

Among the outputs of the color separation circuit 66, a chroma key signal is input to a D/A conversion circuit 80. The D/A conversion circuit 80 has Y, M,
D/A converters 82a to 82d provided for each of C,
Amplifiers 84a to 84d1 have a blanking signal mix circuit 86.

The output signals Y, M, C, and K of the D/A conversion circuit 80 are sent to the monitor circuit 90 (FIG. 3(C)) via the matrix circuit 88.
is supplied to The matrix circuit 88 has an amplifier, a secondary color correction circuit (YM circuit, MC circuit, CY circuit), and a pedestal circuit (PED), and sends signals to Y, M, and C to approximate the color tone of the displayed image to the printed image. The signals are converted into R, G, and B signals and supplied to adders 92a to 92C in the monitor circuit 90.

Adders 92a to 92C of the monitor circuit 90 add the output R, G, and B signals of the matrix circuit 88 and the output signal of a data processing circuit 134, which will be described later.

A key memory white level adjustment resistor 94 and a key white level adjustment resistor 96 are also connected to the adders 92a to 92c.

The outputs of adders 92a to 92c are input to switching circuit 98. An overlap/chroma key display changeover switch 100 and an overlap 7' key memory display changeover switch 102 are connected to the changeover circuit 98.

The output of switching circuit 98 is input to adders 104a to 104c. Adders 104a to 104c add the output R, G, and B signals of the switching circuit 98 and cross marker, mask, and enlarged frame signals from the CPU 160, which will be described later. The cross marker is used to display a "10" mark at one point within a desired pattern to be used for printing in the displayed image. The enlargement frame signal indicates a frame for enlarging the image in the frame memory 58.

The output R, G, and B signals of the adders 104a to 104c are sent to the color monitor 11 via amplifiers 106a to 106C.
0 and displayed. Therefore, what is displayed is the image of one color separation specified by the selection switch 70. The resolution of the color monitor 110 is 640X400
(pixel).

As shown in FIG. 3(d), the Y, M, and C chroma key signals and luminance key signals output from the color separation circuit 66 are supplied to the silhouette image extraction circuit 112, and the cross marker pixel data is It is latched by latch 114.

A latch pulse that determines the latch timing is supplied from the CPU 160 according to the position of the cross marker.

The chroma key signal (Y, M,
C, K), the luminance key signal is transmitted to the comparators 116a-1
16e. Comparator 116a~
The second input terminal of 116e receives a real-time chroma key signal (Y, M, C, K) output from the color separation circuit 66.
, a luminance key signal is input. Comparator 116a~
The output of the level setter 118 is supplied to 116e, and when the difference between the first and second human input signals is less than the output level of the level setter 118, a detection signal of "H rubel" is generated.

That is, a point whose difference in color and brightness from the cross marker point is equal to or less than a threshold value is detected as a point inside the pattern, and silhouette image information is output. The level setter 118 can set threshold values for each color of Y, M, and C, and K is also used as the luminance key. Here, in reality, the chromakey signals are Y, M, C,
One of the following.

The outputs of the comparators 116a to 116d are connected to the AND gate 120.
The output of the AND gate 120 is connected to the second input terminal of the selector 122 via an inverter 124 . Comparator 118
The output of e is supplied as is to the first input terminal of the selector 126, and is supplied to the second input terminal of the selector 126 via the inverter 128. The selectors 122 and 126 are switched by a key white/black changeover switch 128. The key white/black switch 128 detects the inside of the pattern or
This switch is used to select whether or not to detect the outside; if the pixel that latched data is inside the pattern, the inside is detected; if it is outside the pattern, the outside is detected, and a silhouette image is extracted.

The outputs of the selectors 122 and 126 are supplied to a gate 136E in the data processing circuit 134 via a luminance switch 130 and a chroma switch 132, respectively. Either the luminance switch 130 or the chroma switch 132 is turned on. A drawing/mask signal from the CPU 160 is also supplied to the gate 136 . Add/subtract switch 150 is also connected to gate 136 .

The output key signal (chroma key signal or luminance key signal) of gate 136 is written into key memory 138. Therefore, a silhouette image consisting of dots inside the outline of the desired picture or a silhouette image consisting of dots outside the outline of the desired picture are written into the key memory 138. A freeze switch 140 and an erase switch 142 are connected to the key memory 138. Freeze switch 140
is a switch that temporarily makes the output image of the key memory 138 a still image. Erase switch 142 is key memory 13
This is a switch that clears the data of 8. key memory 1
The output of 38 is connected to CP via GP IB I/F144.
Sent to IB162.

A transmission switch 148 is also connected to the GPIBI/F 144. The data processing circuit 384 is l10164 on the CPU side.
It also has an I/F 146 connected to.

Output signal of key memory 138 (hereinafter referred to as key memory signal)
is fed back to key memory 138 via gate 136. This feedback signal is superimposed on the signal of the key memory 138 in an additive or subtractive manner depending on the designation of the addition/subtraction switch 150. This is used to superimpose detection results using chroma key signals of other colors when detection cannot be performed using only chroma key signals of one color.

The key memory 138 contains an address signal from a timing generation 1562 (FIG. 3(a)), an R/W mode designation signal,
A zoom signal is also provided.

Key signal output from gate 136, key memory 13
The key memory signal output from 8 is supplied to adders 92a to 92c of monitor circuit 90.

As a result, the displayed image on the color monitor 110 becomes an image in which the silhouette image is superimposed on the image of the entire color separation plate.
You can check the results of silhouette image extraction on the display screen. That is, due to the superimposition of the silhouette image, the image inside or outside the pattern becomes lighter.

Variable resistors 94 and 96 are resistors for adjusting these shades. Then, specifying the position of the cross marker as a parameter for silhouette image detection, and comparators 116a to 116e.
The operator can change the threshold for judgment, the color of the chroma key signal, and the selection of chroma key and luminance key. By adjusting the parameters, an accurate silhouette image can finally be extracted.

When the silhouette image extraction is completed, the data processing circuit 134 transfers the data in the key memory 138 to the CPIBI/F 144.
It is sent to the CPU 160 side via.

As shown in FIG. 3(e), the CPU 160 has 1101
64, CPIB162, floppy disk (FDD)
device 166, keyboard 168, 1/F 170. A digitizer 174 is connected to a menu sheet 176. Keyboard 168 specifies the position of the cross marker. I/
F170 supplies the key memory signal supplied via GP I B162 to dot generator 34 via interface unit 4. Specifically, I/F1
The output of 70 is written via a buffer memory 52 to a storage device 50 using a floppy disk storage medium.

This floppy disk is reproduced by the storage device 48 on the color scanner side, and the silhouette image signal is supplied to the dot generator 34 via the buffer memory 46 and I/F 44. Here, when the color scanner 2 and the silhouette image extraction section 6 are directly connected, the output of the 1/F 170 may be directly supplied to the dot generator 34. In addition,
If the outline of the silhouette image is detected to be even slightly large,
Since unnecessary white lines and the like are visible on the outside of the pattern in the printed matter, the CPU 160 corrects the outline of the silhouette image to make it slightly smaller and then supplies it to the dot generator 34 via the I/F 170.

The digitizer 174 is used to manually input contour information when a silhouette image cannot be detected successfully.

The dot generator 34 generates dots in response to this signal, and the exposure head 36 exposes the outside of the pattern on one silver halide film so that the pattern becomes transparent after development.

If a printing plate is created from a color separation plate using the mask created in this way, only the desired pattern of the original will be included in printing.

[Effects of the Invention] As explained above, according to the present invention, an image is displayed based on image signals after color separation output from a color scanner that exposes a color separation film, and extraction is performed while viewing the displayed image. By setting the parameters, it is possible to accurately extract the silhouette image of the desired pattern, and by controlling the exposure section of the color scanner and exposing the silver halide film, a mask can be automatically created. As a result, accurate cutout masks for color separation plates can be created in a short time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an outline of an embodiment of a cutting device according to the present invention, FIG. 2 is a block diagram showing the configuration of a color scanner, and FIG. 3 is a block diagram showing the configuration of an interface unit and a silhouette image extraction section. It is. 2...Color scanner, 58...Frame memory,
66... Color separation circuit, 90... Monitor circuit, 112...
. . . Contour extraction circuit, 134 . . . Data processing circuit. Applicant's agent Patent attorney Takehiko Suzue Figure 1

Claims (1)

[Claims] means for displaying an image based on color-separated image signals output from a color scanner that exposes a color-separated film; means for specifying a point within a desired picture area in the displayed image; means for extracting a silhouette image of the desired pattern by comparing the difference between the brightness or color of one point and the brightness or color of each point of the displayed image with a predetermined value, A cutting device that creates a color separation mask by controlling the exposure section of a color scanner based on the extracted silhouette image.