JP2639490B2 - Color image recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to halftone dots on a photosensitive material such as a photographic film and a recording medium such as a charging drum based on image signals of a plurality of color separation images obtained by color separation of a color original image. The present invention relates to a color image recording apparatus for recording a color image in a format.

[0002]

2. Description of the Related Art When printing a color image, it is common to prepare a calibration image before the final printing process to check the quality of the printed image. In the conventional simple calibration method (chemical calibration method), for example, yellow (Y),
Using color separation halftone image films for magenta (M), cyan (C), and black (K) plates, each halftone image was sequentially printed on a color printing paper dedicated to proofreading to produce a proofreading image. .

[0003]

However, in the conventional simple calibration, the ink around the halftone dot during printing, which is generated by the influence of the printing pressure or dampening solution left on the halftone dot of the printing plate, is used. Diffusion could not be simulated, which caused a problem that the image quality of the color image for calibration and the image quality of the actual printed matter differed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art, and has as its object to provide a color image recording apparatus capable of simulating the diffusion of ink around halftone dots during printing. Aim.

[0005]

Means for Solving the Problems In order to achieve such an object, the following structure is adopted as means for solving the above problems.

That is, the color image recording apparatus of the present invention is a color image recording apparatus for recording a color image in a halftone dot format on a recording medium based on image signals of a plurality of color separation images obtained by color separation of a color original image. An apparatus for displaying each color separation image as a halftone image based on the image signal.
A halftone dot signal generating means for generating a halftone dot signal of a value, and a multi-valued diffusion simulation halftone dot having a smoothed peripheral portion of each halftone dot of the halftone image by applying a weighted integration process to the halftone dot signal. Diffusion simulating halftone dot signal creating means for creating a signal; recording means for recording a halftone image on the recording medium at a recording level based on the value of the diffusion simulating halftone dot signal created by the diffusion simulated halftone dot signal creating means; Is provided.

In this apparatus, the diffusion simulating halftone signal generating means includes a spatial filter signal output means for outputting a predetermined weighting signal, and a halftone signal generated by the weighting signal and the halftone signal generating means. It is preferable that the image processing apparatus further comprises an arithmetic unit for calculating a diffusion simulated halftone dot signal in which peripheral portions of each halftone dot of the halftone image are smoothed by calculating the sequentially extracted halftone dot signals.

Further, the spatial filter signal output means includes:
× N weighting signal is output, and the diffusion simulated halftone signal generating means temporarily stores at least two scans of the halftone signal output from the halftone signal generation means, and stores the first halftone signal of the stored two scans. It is preferable to include an addition halftone dot signal output means for adding the (N-1) halftone signals of the following second scan to the scanning means and sequentially outputting the extracted halftone signals to the arithmetic means.

[0009]

According to the present invention, based on image signals of a plurality of color-separated images obtained by color-separating a color original image, a halftone-dot signal generating unit performs
A binary halftone signal representing each color separation image as a halftone image is created. Then, by performing a weighted integration process on the halftone dot signal by the diffusion simulation halftone dot signal creation means, a multi-valued diffusion simulation halftone dot signal in which the periphery of each halftone dot of the halftone image is smoothed is created, A color image is recorded on a recording medium in a halftone dot format by the recording means based on the created diffusion simulated halftone dot signal. Here, the recording means records at a recording level based on the value of the diffusion simulated halftone dot signal, so that blurred halftone dots in the peripheral portion are recorded on the recording medium.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to further clarify the structure and operation of the present invention described above, preferred embodiments of the present invention will be described below.

FIG. 1 is a diagram showing a configuration of a scanner system as a first embodiment of the present invention. This scanner system includes a color scanner 100 and a calibration image recording device 200. The color scanner 100 includes an input drum 101 and an output drum 102. The input drum 101 has a color original OF, and the output drum 102 has a recording for recording a halftone image obtained by color separation. Each of the films RF is wound.

When reading the original image data by scanning the original image OF, the input drum 101 rotates at a constant speed in the θ direction, and the scanning head 103 is moved by the feed screw 104 in a direction parallel to the rotation axis of the input drum 101. Is moved at a constant speed. Light emitted from a light source (not shown) provided inside the input drum 101 passes through the transparent input drum 101 and the original color image OF, and is thereafter received by the scanning head 103. The blue (B), green (G), and red (R) components of the light collected by the scanning head 103 are reflected by two dichroic mirrors 105a and 105b and one reflecting mirror 105c, respectively. The three reflected lights are individually converted into electric signals by the photomultiplier tube 106, and then blue, green, and blue by amplifiers 107a to 107c.
The signals are converted into red density signals Sb, Sg, and Sr, respectively.
These density signals Sb, Sg, and Sr are applied to a masking circuit 108, where they undergo color correction, gradation conversion, and other processing to produce image signals Sy representing Y, K, M, and C color separation images, respectively. , Sk, Sm, Sc. The image signals Sy, Sk, Sm, Sc are converted into digital signals by the A / D converter 109 and supplied to the dot generator 110. Digital image signals Sy, Sk,
Sm and Sc are gradation level signals expressing 256 gradations with, for example, 8 bits.

When a halftone image of each of Y, K, M, and C is recorded on the recording film RF, the dot generator 110 converts the halftone dot signal Sd based on the digital image signals Sy, Sk, Sm, and Sc. Occur. This dot signal Sd is
AOM (acousto-optic modulator) 111 controls laser light source 1
The on / off control of the laser light L emitted from 12 is performed.
The laser light L passing through the AOM 111 is transmitted to the recording head 11
The recording film RF condensed at 3 and wound around the output drum 102 is exposed. As a result, a halftone image of each of the Y, K, M, and C plates is recorded on the recording film RF. During this recording operation, the output drum 102 rotates in the θ direction at a constant speed, and the recording head 113
Accordingly, the output drum 102 is moved at a constant speed in a direction parallel to the rotation axis of the output drum 102.

When a calibration image is created, the digital image signals Sy, Sk, Sm, Sc are converted into color images by the color scanner 10.
0 to the calibration image recording device 200. The calibration image recording device 200 includes an interface circuit 201,
Color operation circuit 202, dot generator 203, K
Plate signal combining circuits 204y, 204m, 204c, filtering circuits 205y, 205m, 205c, and D /
A converter 206, laser light sources for emitting laser beams of B, G, and R colors (not shown), and AOM units 207y, 207m, and 207y for controlling on / off of the laser beams of the respective colors.
207c, a reflection mirror 208a, dichroic mirrors 208b and 208c, an exposure head 209, and a drum 210.

In the calibration image recording apparatus 200, digital image signals Sy, Sk, Sm, Sc are supplied to a color operation circuit 202 via an interface circuit 201. The color operation circuit 202 has a function of performing color correction and gradation correction of each digital image signal Sy, Sk, Sm, Sc so that the color tone of the image for calibration and the color tone of the image on the printed matter match.

The image signal S corrected by the color operation circuit 202
y1, Sk1, Sm1 and Sc1 are inputted in parallel to the dot generator 203 for four channels, and the halftone signals S
dy, Sdk, Sdm, and Sdc. These halftone signals Sdy, Sdk, Sdm, and Sdc are binary signals that are H level or L level. For example, exposure is performed at H level, and exposure is not performed at L level. Therefore, the halftone signals Sdy, Sdk, Sd
Halftone dots are formed based on the arrangement of m and Sdc, and these halftone dots are equivalent to halftone dots recorded by the color scanner 100. In this embodiment, since the color photographic material is exposed by simultaneously using ten exposure beams as described later, each halftone signal Sdy, Sdk, Sdm, Sdc controls ten exposure beams. It is configured as a 10-bit signal.

The screen ruling and screen angle of the halftone image of each of the Y, K, M, and C planes are set to predetermined values by the dot generator 203, respectively. A method of arbitrarily setting the screen ruling and the screen angle of the halftone image is disclosed in, for example, JP-A-55-6393,
This is described in detail in JP-A-61-137473.

The chromatic halftone dot signals Sdy, Sdm, Sdc
Are input to the K-version signal combining circuits 204y, 204m, and 204c together with the K-version halftone signal Sdk. Each of the K version signal synthesizing circuits 204y, 204m, 20
4c is a composite halftone signal Sdy1, which represents the union of the halftone dots of the Y, M, and C versions and the halftone dots of the K version by taking the logical sum or logical product of the two input signals. Sdm
1, Sdc1 is created. As a result, in the area to be the halftone dot of the K plane, all three colors of Y, M, and C are colored to become black, and the halftone dots of four colors of Y, M, C, and K are formed on the color photosensitive material. Can be recorded. The configuration and processing contents of the K-version signal synthesizing circuit are described in detail in Japanese Patent Application No. 1-285823 filed by the present applicant.

The K-version signal synthesizing circuits 204y, 204m, and 2
The synthesized halftone dot signals Sdy1, Sdm1, and Sdc1 each having 10 bits generated in 04c are input to filtering circuits 205y, 205m, and 205c, respectively.
Here, the diffusion of the ink around the halftone dot is simulated, and the 10-bit diffusion simulated halftone dot signals Sdy2, Sdm2,
Sdc2 is output. The filtering circuit 20
The configurations and processing contents of 5y, 205m, and 205c will be further described later.

Each of the diffusion simulated halftone dot signals Sdy2, Sdm2,
The Sdc2 is converted into an analog signal by the D / A converter 206, and is converted into AOM units 207y, 207m,
207c. Each of the AOM units 207y, 207m, and 207c is composed of 10 channels of AOMs, and controls on / off of ten exposure beams. Also, the AOM unit 207
y, 207m, and 207c control exposure beams B, G, and R of blue, green, and red, respectively. Exposure beams B, G, and R modulated by AOM units 207y, 207m, and 207c are reflected by reflection mirror 208.
a, apparently combined into ten beams by dichroic mirrors 208b and 208c, and exposure head 209
Thus, the color photographic material PF wound on the drum 210 after being imaged at the light spot is exposed, and a calibration image is recorded on the color photographic material PF. In this exposure, the drum 21
0 rotates at a constant speed in the φ direction and moves at a constant speed in a direction parallel to the rotation axis.

Thus, in this scanner system,
Diffusion simulation halftone signals Sdy2, Sdm2, and Sdc2 that simulate the diffusion of ink around the halftone dots during printing are created by the filtering circuits 205y, 205m, and 205c.
Since the calibration image is recorded based on these signals, there is an advantage that the image quality of the calibration image can be checked in a state where the ink around the halftone dot during printing is simulated.

Further, the K-version signal synthesizing circuits 204y, 20
4m, 204c, the image signals Sdy1, Sdm1, and Sdc expressing the K halftone dot superimposed on other halftone dots.
So, for example, like a silver halide photographic material,
A calibration image can be directly recorded on an output medium having only the Y, M, and C coloring layers based on these signals. By the above-described processing, there is an advantage that the calibration image can be directly created from the image signal instead of creating the calibration image after recording the color separation halftone image on a film or the like as in the related art. That is, even if there is a portion to be corrected in the proofing image, it is not necessary to re-create the color separation halftone image on the film.

Next, the configuration and operation of the filtering circuit will be described in detail. FIGS. 2 and 3 are block diagrams showing the internal configuration of the Y-version filtering circuit 205y. Filtering circuits 205m and 205 of other versions
Regarding the configuration of c, the Y-version filtering circuit 20
5y and the description is omitted. Note that the synthesized halftone signal Sdy1 input to the filtering circuit 205y
Is a 10-bit signal as described above. Here, for the sake of simplicity of the drawing and the description, it is assumed that the color photosensitive material is exposed using five exposure beams simultaneously. Sdy1 is a 5-bit signal.

The filtering circuit 205y includes first and second line ring memories 300 and 301, first and second latch circuit groups 302 and 303, and first to fifth arithmetic circuits 304, 305, 306, 307, 30
8 is provided. In the filtering circuit 205y, the input halftone dot signal Sdy1 is converted into dot signals Sdy11, Sdy12, S
The data is supplied to the first line ring memory 300 for each of dy13, Sdy14, and Sdy15. First line ring memory 300 (same for second line ring memory 301)
Is a combined halftone dot signal Sd for one scan of five exposure beams.
5 × n for storing y1 (n is the number of dots in the main scanning direction)
Each time one 5-bit synthetic halftone signal Sdy1 is input to the bit memory, the stored halftone dot signal Sdy is stored.
1 in the main scanning direction (the right direction in the figure), and outputs 5 bits of the rightmost synthesized dot signal Sdy1 to the outside.

The combined halftone dot signal Sdy 1 output from the first line ring memory 300 is input to the second line ring memory 301. Second line ring memory 3
01, like the first line ring memory 300,
Synthetic halftone signal Sdy1 for one scan of five exposure beams
Is stored, and every time the synthesized dot signal Sdy1 output from the first line ring memory 300 is input, the stored synthesized dot signal Sdy1 is shifted in the main scanning direction. Then, the synthesized halftone dot signal Sdy1 is output to the outside from the rightmost end.

The combined halftone dot signal Sdy1 output from the second line ring memory 301 is supplied to the first latch circuit group 3
02. The first latch circuit group 302 serially connects three 5-digit latch circuits so that three stages of 5-bit composite halftone dot signal Sdy1 can be stored and held in the input order. Update the stored contents of the circuit.

On the other hand, the dot signals Sdy11 and Sdy12 stored at the rightmost end of the first line ring memory 300
, Is also supplied to the second latch circuit group 303 at the same time as being input to the second line ring memory 301.
The second latch circuit group 303 outputs the dot signal Sdy1
1, so that three stages of Sdy12 can be stored and held in the input order.
Three digit latch circuits are serially connected, and when a clock is externally supplied, the stored contents of each latch circuit are updated. This clock is synchronized with the timing at which the combined halftone dot signal Sdy1 is input to the first line ring memory 300.

The operation of the first and second line ring memories 300 and 301 and the first and second latch circuit groups 302 and 303 thus configured will now be described. When the combined halftone dot signal Sdy1 is input to the filtering circuit 205y, the dot signals Sdy11 to Sdy15 are
First, the data is input to the first line ring memory 300 and 5
Combined halftone signal Sd for the first scan in which one set of scan lines is used
y1 is stored in the first line ring memory 300.
Subsequently, the combined halftone signal Sdy1 for the second scan is sequentially input to the first line ring memory 300, but the combined halftone signal Sdy1 for the second scan is entirely stored in the first line ring memory 300. At this time, the second halftone memory 301 stores the combined halftone dot signal Sdy1 for the first scan.

Thereafter, the synthesized halftone signal Sdy for the third scan is obtained.
1 is input to the first line ring memory 300, but every time one synthesized dot signal Sdy1 is input, the earliest synthesized dot signal Sdy1 is output from the second line ring memory 301. And the first latch circuit group 302
And at the same time, the first line ring memory 3
01, the earliest dot signals Sdy11 and Sdy12 in the first line ring memory 301 are output and stored in the second latch circuit group 303.

As a result, when the combined halftone signal Sdy1 for the third scan is input to the first line ring memory 300, the first latch is set when the third combined halftone signal Sdy1 is input. In the circuit group 302, the first, second, and third combined halftone dot signals Sdy1 on five scanning lines whose coordinate values in the sub-scanning direction are 1, 2, 3, 4, and 5 are provided.
Is stored and stored in the second latch circuit group 303.
First, second, and third dot signals Sdy on two scanning lines whose coordinate values in the sub-scanning direction are 6, 7
11 and Sdy12 are stored and held.

Thereafter, the first line ring memory 300
The fourth combined halftone signal Sd in the third scanning direction in the main scanning direction.
When y1 is inputted, the second, third, and fourth scan lines on five scan lines whose coordinate values in the sub-scanning direction are 1, 2, 3, 4, and 5 are input to the first latch circuit group 302. The second halftone dot signal Sdy1 is stored and held, and the second latch circuit group 303 stores the second, third, and second scan lines on two scan lines whose coordinate values in the sub-scanning direction are 6,7. The fourth dot signals Sdy11 and Sdy12 are stored and held.

That is, as shown in FIG. 4, in the entire image indicated by the coordinate value x in the sub-scanning direction and the coordinate value y in the main scanning direction, first, the coordinate values of x are 1 to 7 and the coordinate values of y are Is 1
Each dot signal in the region R11, which is 3, the region R12 in which the coordinate value of x is 1 to 7 and the coordinate value of y is 2 to 4
Of the first latch circuit group 302 and the second dot signal
Are extracted by the latch circuit group 303.

Thereafter, the extraction area is shifted by one signal in the y direction, and the coordinate value of x is 1 to 7 and the coordinate value of y is n−n.
The dot signals up to the region R1 (n-2), which is 2, n-1, n, are extracted. Then, the coordinate value of x is 6-12,
dot signal x in the region R21 in which the coordinate values of y are 1-3
Are sequentially extracted in the order of dot signals in the region R22 in which the coordinate values of are 6 to 12 and the coordinate values of y are 2 to 4. In this manner, dot signals of a 7 × 3 area are sequentially extracted from the entire image area. Each of the dot signals of the extracted area is first to fifth arithmetic circuits 304 to 3 for each area.
08.

Hereinafter, the first to fifth arithmetic circuits 304 to
308 will be described in detail. First arithmetic circuit 304
Performs weighting by applying a weighting function (spatial filter), which is a 3 × 3 matrix shown in FIG. 5, to a 3 × 3 element, and comprises a multiplication circuit in which three multiplication circuits are arranged. Group and three sets of adder circuits for adding outputs from the respective multiplier circuits (multiplier circuit groups 400a, 400b, 4).
00c, adders 401a, 401b, 401c) and an adder 402 for adding the outputs from the adders 401a, 401b, 401c. The nine multiplication circuits composed of three multiplication circuit groups 400a, 400b, and 400c include each element A of the weight function.
To I, and the values of the three-stage latch circuits from the top of the first latch circuit group 302 are input to the other end.

With the configuration of the arithmetic circuit 304, the following diffused dot signal Sdy21 is output. Sdy21 = HA.S11 + HB.S21 + HC.S31 + HD.S12 + HE.S22 + HF.S32 + HG.S13 + HH.S23 + HI.S33 where HA, HB,..., HI are weights. Each element A of the function
It shows the value of I. S11, S21,... Indicate the values of the respective latch circuits included in the first latch circuit group 302 as SUV using the coordinate value u in the lower direction in the figure and the coordinate value v in the left direction in the figure. It is.

The second arithmetic circuit 305 has the same configuration as that of the first arithmetic circuit 304. One end of each of the multiplication circuits is provided with the second to fourth digit latch circuits of the first latch circuit group 302. Values have been entered for each. With such a configuration, the following diffused dot signal Sdy22 is output. Sdy22 = HA.S21 + HB.S31 + HC.S41 + HD.S22 + HE.S32 + HF.S42 + HG.S23 + HH.S33 + HI.S43

The third arithmetic circuit 306 has the same configuration as that of the first arithmetic circuit 304. One end of each of the multiplication circuits is provided with the third to fifth digit latch circuits of the first latch circuit group 302. Values have been entered for each. With such a configuration, the following diffused dot signal Sdy23 is output. Sdy23 = HA.S31 + HB.S41 + HC.S51 + HD.S32 + HE.S42 + HF.S52 + HG.S33 + HH.S43 + HI.S53

The fourth arithmetic circuit 307 has the same configuration as the first arithmetic circuit 304. One end of each of the multiplying circuits is connected to the fourth, fifth and second digits of the first latch circuit group 302. The value of the first digit latch circuit of the latch circuit group 303 is input. With such a configuration, the following diffused dot signal Sdy24 is output. Sdy24 = HA.S41 + HB.S51 + HC.S61 + HD.S42 + HE.S52 + HF.S62 + HG.S43 + HH.S53 + HI.S63 where S61, S62 and S63 are the second Latch circuit group 30
3 shows the value of the first digit latch circuit.

The fifth arithmetic circuit 308 has the same configuration as the first arithmetic circuit 304. One end of each of the multiplying circuits is provided with a fifth digit of the first latch circuit group 302 and a second latch circuit group 303. The values of the first and second digit latch circuits are respectively input. With such a configuration, the following diffused dot signal Sdy25 is output. Sdy25 = HA.S51 + HB.S61 + HC.S71 + HD.S52 + HE.S62 + HF.S72 + HG.S53 + HH.S63 + HI.S73 where S71, S72 and S73 are the second Latch circuit group 30
3 shows the value of the second digit latch circuit.

In this way, the weighted integration processing for the 3 × 3 elements is performed on the entire image area for each 7 × 3 area extracted from the first latch circuit group 302 and the second latch circuit group 303. The diffusion dot signal Sdy21
To Sdy25 to form a diffusion simulated halftone dot signal Sdy2.

Hereinafter, the filtering circuits 205y, 20
The following describes how the combined halftone signals Sdy1, Sdm1, and Sdc1 input to the filtering circuits 205y, 205m, and 205c change by the weighted integration processing of 5m and 205c. Prior to the description, the halftone area HD, the dots forming the halftone area, and the synthesized halftone signal Sdy
1, Sdm1, and Sdc1 will be described with reference to FIG. Here, the halftone dot area is an area that is a repeating unit of halftone dots, and is an area occupied by halftone dots when the halftone dot area ratio is 100%. In this embodiment, taking the case where the screen angle is 0 ° as an example, the halftone dot region HD is composed of approximately 23 × 23 dots. The number of dots obtained in the sub-scanning direction by one main scan is such that the color photosensitive material is exposed by simultaneously using ten exposure beams as described above, so that ten dots (FIGS. 2 and 3) are used. 5 in the example shown). Therefore, one halftone dot is formed in the sub-scanning direction by two or more (approximately 2.3) main scans. Then, each dot signal constituting the combined halftone dot signals Sdy1, Sdm1, and Sdc1 corresponds to each dot on a one-to-one basis.

The composite halftone signals Sdy1, Sdm
In the case where the 3 × 3 weighted integration processing is simply performed on 1, Sdc1 in the input order, as described above, one halftone dot region is larger than the number of dots in the sub-scanning direction obtained by one main scan. Since it is composed of the number of dots in the sub-scanning direction, the main scanning boundary line (the line segment K1K2 and the line segment K
The weighted integration process acts on the dot above (3K4 is equivalent) as the periphery of the halftone dot. On the other hand, the filtering circuits 205y, 205m, 20
5c, as described above, 12 dots are added to the sub-scanning direction obtained by adding two dots to the sub-scanning direction obtained in one main scan.
(7) Since the dot signals corresponding to the dots are once extracted and then subjected to the 3 × 3 weighted integration process, it is possible to perform a process without erroneous recognition even for the dots on the boundary line of the main scanning.

FIG. 7 shows a dot signal group G1 based on the synthesized halftone signal Sdy1 input to the filtering circuit 205y.
FIG. 9 is an explanatory diagram showing a comparison between a diffusion dot signal group G2 based on a diffusion simulation halftone dot signal Sdy2 output from a filtering circuit 205y. In FIG. 7, the synthesized halftone signal S
The dot signal group G1 based on dy1 has a dot area ratio of 50%.
For example, exposure is performed by an H level (= 1) dot signal, and exposure is not performed by an L level (= 0) dot signal. However, for the sake of simplicity, the dot configuration of the halftone dot area HD in FIG.
Not three. When the dot signal group G1 based on the composite halftone signal Sdy1 is input to the filtering circuit 205y, the diffusion circuit 205y outputs a diffusion dot signal group G2 based on the diffusion simulation halftone signal Sdy2. The diffusion dot signal group G2 is a multi-level signal, and the level of the signal becomes lower as approaching the periphery of the halftone dot.

The diffusion simulated halftone dot signal Sdy2 is converted into an analog signal by the D / A converter 206 as described above. At this time, the maximum level value (value 1 in the example of FIG. 7)
In 6), the voltage level generated when the value of the binary level is 1 is given. In the first quadrant of FIG. 8, the voltage level after D / A conversion of the signal of the k-th row of the diffusion dot signal group G2 shown in FIG. 7 is shown. As can be seen from FIG.
From the A converter 206, an output of an analog signal in which the periphery of the halftone dot is smoothed is obtained.

The voltage signal after the D / A conversion is applied to the AOM unit 207y as described above, and the AOM unit 207y modulates the exposure beam in accordance with the voltage signal and changes the beam transmittance. Then, the exposure beam is irradiated onto the color photosensitive material PF via the exposure head 209, and an image is recorded at a density corresponding to the photosensitive characteristics of the color photosensitive material PF. The characteristics of the AOM unit 207y are shown in the second quadrant of FIG. 8, the characteristics of the color photosensitive material PF are shown in the third quadrant of FIG. 8, and the density of the image as the exposure result is shown in the fourth quadrant of FIG. In FIG. 8, the one indicated by the two-dot chain line is a halftone dot based on the dot signal group G1, whereas the diffuse dot signal group G2 shows that halftone dots with blunt edges are obtained. For this reason, an output in which the periphery of the halftone dot is blurred is made as the exposure result.

Therefore, the calibration image created by the calibration image recording device 200 of the present embodiment simulates the diffusion of ink around the halftone dots during actual printing.
The image quality of the proofreading image and the image quality of the printed matter printed by the color scanner 100 match well.
For this reason, the image quality can be confirmed with the calibration image in a state where the diffusion of the ink around the halftone dot at the time of printing is simulated. Note that the diffusion simulation halftone dot signals Sdy1, Sdm1,
The rounded shape of the halftone dot indicated by Sdc1 changes depending on the value of the weighting function shown in FIG. 5, so that the printing pressure during printing and the amount of residual dampening water left on the halftone dot of the printing plate are reduced. By empirically changing the value of the weight function accordingly, it is possible to more suitably simulate the diffusion of the ink around the halftone dot during printing, the degree of which changes according to the printing pressure and the amount of residual dampening water. Can be.

Next, a second embodiment of the present invention will be described. The scanner system according to the second embodiment includes a color scanner having the same configuration as that of the first embodiment, and a calibration image recording apparatus having a configuration different from that of the first embodiment. The calibration image recording apparatus 200 according to the first embodiment has a configuration in which filtering circuits 205y, 205m, and 205c are provided at the subsequent stage of the K-plate signal synthesizing circuits 204y, 204m, and 204c. In the image recording apparatus for calibration in the above, the K-version signal synthesizing circuits 204y, 204m,
This is a configuration in which a filtering circuit is provided at a stage prior to 204c.

FIG. 9 shows such a calibration image recording device 30.
FIG. 3 is a diagram showing a configuration of a zero. As shown in FIG. 9, the digital image signals Sy, S
k, Sm, Sc are the same color operation circuit 20 as in the first embodiment via the same interface circuit 201 as in the first embodiment.
2 given. The image signals Sy1, Sk1, Sm1, and Sc1 corrected by the color operation circuit 202 are serially converted by a parallel / serial converter 301, and thereafter, are input to a dot generator 303 and input to a dot signal S3.
dy, Sdk, Sdm, and Sdc. The halftone signals Sdy, Sdk, Sdm, and Sdc are input to a filtering circuit 305. Here, as in the first embodiment, the diffusion of ink around the halftone dots is simulated.
Bit diffusion simulation halftone dot signals SdyA, SdkA, Sdm
A and SdcA are output.

The diffusion simulated halftone dot signals SdyA, Sdk
A, SdmA, and SdcA are converted into parallel by a serial / parallel converter 306, and are input to the same K-plate signal combining circuits 204y, 204m, and 204c as in the first embodiment. K version signal synthesis circuit 204y, 204
m, 204c, the synthesized halftone signals SdyB, Sd
mB and SdcB are the same D / A converter 2 as in the first embodiment.
06, the signals are converted into analog signals, and the same AOM units 207y, 207m, and 207c as in the first embodiment.
Respectively. The color photographic material PF wound on the drum 210 is exposed in the same manner as in the first embodiment, and a calibration image is recorded on the color photographic material PF.

In the second embodiment configured as described above,
As in the first embodiment, the calibration image created by the calibration image recording device 300 simulates the diffusion of ink around the halftone dots during actual printing, and the calibration image The image quality can be confirmed in a state in which the diffusion of the ink around the halftone dot is simulated. Moreover, in this embodiment, since data is serially transferred to the filtering circuit 305, there is no need to arrange three filtering circuits in parallel as in the first embodiment, and a compact configuration can be achieved.

In this embodiment, the K-version signal synthesizing circuit 2
Since the filtering circuit 305 is provided at the preceding stage of the halftone signals Sdy, Sdm, Sdc, and the K halftone signal Sdk as well as the chromatic halftone signals Sdy, Sdm, Sdc. A peripheral part is smoothed. For this reason, even when a halftone dot of the K plane partially overlaps a halftone dot of the chromatic color, it is possible to simulate the diffusion of the ink around the halftone dot of the K plane corresponding to the boundary between the two. . The diffusion of the black layer on the chromatic layer at the time of printing is not remarkable as compared with the case where black is directly on the color photosensitive material PF. , K can sufficiently simulate the diffusion of the ink around the halftone dots.

In the first and second embodiments,
As a recording means, a color photosensitive material PF as a photosensitive recording medium
Although a configuration for optically recording an image is employed above, an electrophotographic configuration may be employed instead. That is, an electrostatic latent image is obtained by irradiating a laser beam modulated in accordance with a diffusion simulation signal, in which the periphery of each halftone dot of the halftone image is smoothed, to obtain an electrostatic latent image and apply the electrostatic latent image to the electrostatic latent image. A color image may be recorded by attaching toner. When the color image for calibration is scanned and exposed using the configuration of the electrophotography, only one type of laser may be used (for example, a semiconductor laser, a He-Ne laser, an Ar laser).
Laser, Y, M, C, and K toners, or use a photosensitive material that is previously colored in each of the four colors to independently expose the Y, M, C, and K plates. do it.

Although several embodiments of the present invention have been described above, the present invention is not limited to these embodiments at all, and may be made within the scope of the present invention.
Of course, it can be implemented in various modes.

[0054]

According to the color image recording apparatus of the present invention described above, it is possible to record a color image simulating the diffusion of ink around the halftone dot during printing. Therefore, the quality of the image printed in a state of simulating the diffusion of the ink around the halftone dot at the time of printing can be confirmed from the color image.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of a scanner system as a first embodiment of the present invention.

FIG. 2 is a block diagram showing a part of an internal configuration of a filtering circuit 205y.

FIG. 3 is a block diagram illustrating another part of the internal configuration of the filtering circuit 205y.

FIG. 4 is an explanatory diagram showing an area of a dot signal extracted by a filtering circuit 205y.

FIG. 5 is an explanatory diagram showing a 3 × 3 weighting function;

FIG. 6 is an explanatory diagram showing a relationship between a halftone dot region HD and dots forming halftone dots.

FIG. 7 shows a dot signal group G1 based on a combined halftone dot signal Sdy1 input to a filtering circuit 205y, and a diffusion simulated halftone dot signal Sd output from the filtering circuit 205y.
FIG. 9 is an explanatory diagram showing a comparison with a diffusion dot signal group G2 based on y2.

FIG. 8 is a diagram illustrating a relationship between a voltage level after D / A conversion and an image as an exposure result thereof.

FIG. 9 is a schematic configuration diagram illustrating a configuration of a calibration image recording apparatus of a scanner system according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 100 color scanner 200 calibration image recording device 203 dot generator 204y, 204m, 204c K-plate signal synthesis circuit 205y, 205m, 205c filtering circuit 207y, 207m, 207c AOM unit 209 exposure head 300, 301 line ring memory 302, 303 latch circuit Groups 304, 305, 306, 307, 308 Arithmetic circuit PF Color sensitive material Sdy, Sdk, Sdm, Sdc Halftone signal Sdy1, Sdm1, Sdc1 Composite halftone signal Sdy2, Sdm2, Sdc2 Diffusion simulation halftone signal 303 Dot generator 305 Filtering circuit

Claims (3)

(57) [Claims] 1. A color image recording apparatus for recording a color image in a halftone dot format on a recording medium based on image signals of a plurality of color-separated images obtained by color-separating a color original image. A halftone signal generating means for generating a binary halftone signal representing each of the color-separated images as a halftone image based on the halftone image; and performing a weighted integration process on the halftone signal to thereby obtain each halftone dot of the halftone image. A diffusion simulated halftone dot signal creating means for creating a multi-valued diffusion simulated halftone signal having a smoothed peripheral portion; and a recording level based on the value of the diffusion simulated halftone dot signal created by the diffusion simulated halftone dot signal creating means. Recording means for recording a halftone image on the recording medium. 2. The color image recording apparatus according to claim 1, wherein the diffusion simulation halftone dot signal creating unit outputs a predetermined weighting signal, and a spatial filter signal output unit.
By calculating the weighted signals and the extracted halftone signals sequentially extracted from the halftone signals generated by the halftone signal generation means, a diffusion simulation in which each halftone dot portion of the halftone image is smoothed is performed. A color image recording apparatus comprising: an arithmetic unit for generating a halftone signal. 3. The color image recording apparatus according to claim 2, wherein the spatial filter signal output means outputs an M × N weighted signal, and the diffusion simulated halftone signal generating means includes a halftone signal generating means. Is stored once for at least two scans of the halftone signal output from, and N-1 halftone signals of the subsequent second scan are added to the stored first scan for the two scans, and sequentially. A color image recording apparatus comprising an addition dot signal output means for outputting an extracted dot signal to a calculation means.