JPH04333052A - Color image recorder - Google Patents

Abstract

PURPOSE:To record a color image for simulating the diffusing of the ink of the circumferential part of a dot at the time of printing. CONSTITUTION:Synthetic dot signals Sdy1, Sdm1, and Sdc1 that the dots of each plate of Y, M, and C, are synthesized with the dot of a K-plate, are extracted as the signals of 12 bits that the dot signals of one scan have the addition of two dot signals of the next scan, and inputted into filtering circuits 205y, 205m, and 205c, attaining filtering with a weighting function as the matrix of 3X3. Consequently, the dot signals of each plate are outputted after the circumferential part of the dot is smoothened, and beams for an exposure are modulated, based on these outputted scattering/simulating dot signals Sdy2, Sdm2, and Sdc2, to obtain a color image for correcting.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention creates halftone dots on a photosensitive material such as a photographic film or a recording medium such as a charging drum based on image signals of a plurality of color-separated images obtained by color-separating a color original image. The present invention relates to a color image recording device that records a color image in a format.

0002

2. Description of the Related Art When printing a color image, it is common to create a proof 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),
Color separation halftone image films for magenta (M), cyan (C), and black (K) versions were used, and each halftone image was sequentially printed on color photographic paper for proofing to create proof images. .

0003

[Problems to be Solved by the Invention] However, in conventional simple proofreading, ink loss around the halftone dots during printing occurs due to the influence of printing pressure and dampening water left on the halftone dots of the printing plate. Diffusion cannot be simulated, and as a result, there is a problem in that the image quality of the color image for proofing differs from the image quality of the actual printed matter.

The present invention has been made to solve the above-mentioned problems in the prior art, and it is an object of the present invention to provide a color image recording device that can simulate the diffusion of ink around halftone dots during printing. purpose.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the following configuration was adopted as a means for solving the above problems.

That is, the color image recording apparatus of the present invention records a color image in 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. 2 representing each color separation image as a halftone image based on the image signal;
a halftone signal generating means for creating a value halftone signal, and a multi-valued diffusion simulated halftone dot in which the periphery of each halftone dot of the halftone image is smoothed by subjecting the halftone signal to a weighted integral process. a diffusion simulated halftone signal creating means for creating a signal; and a recording means for recording a halftone image on the recording medium at a recording level based on the value of the diffusion simulated halftone signal created by the diffusion simulated halftone signal creating means. Equipped with

In this apparatus, the diffusion simulated halftone signal generating means includes a spatial filter signal outputting means for outputting a predetermined weighted signal, and a halftone dot signal generated by the weighting signal and the halftone signal generating means. It is preferable to include a calculation means for creating a diffused simulated halftone signal in which the periphery of each halftone dot of the halftone image is smoothed by computing the extracted halftone dot signals that are sequentially extracted.

Furthermore, the spatial filter signal output means includes M
xN weighted signals, the diffusion simulated halftone signal creation means temporarily stores at least two scans of the halftone dot signal output from the halftone signal generation means, and the first halftone signal for the two stored scans. It is preferable to include addition halftone signal output means for adding N-1 halftone dot signals of the subsequent second scan to the scan and sequentially outputting the resultant halftone dot signals to the calculation means as extracted halftone signals.

[0009]

[Operation] Based on the image signals of a plurality of color-separated images obtained by color-separating a color original image, the halftone signal generating means generates a
Binary halftone signals representing each color separation image as a halftone image are created. Then, by subjecting the halftone dot signal to weighted integration processing by the diffusion simulated halftone signal creation means, a multivalued diffusion simulated halftone signal in which the peripheral portion of each halftone dot of the halftone image is smoothed is created; Based on the created diffusion simulated halftone signal, a color image is recorded on the recording medium in halftone format by the recording means. Here, since the recording means records at a recording level based on the value of the diffusion simulated halftone signal, blurred halftone dots at the periphery are recorded on the recording medium.

0010

EXAMPLES In order to further clarify the structure and operation of the present invention described above, preferred examples of the present invention will be described below.

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

When scanning the original image OF to read the original image data, the input drum 101 rotates at a constant speed in the θ direction, and the scanning head 103 is rotated 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 is received by the scanning head 103 after passing through the transparent input drum 101 and the color original OF. The blue (B), green (G) and red (R) components of the light focused by the scanning head 103 are reflected by two dichroic mirrors 105a, 105b and one reflection mirror 105c, respectively. The three reflected lights are individually converted into electric signals by a photomultiplier tube 106, and then converted into blue, green, and blue signals by amplifiers 107a to 107c.
These 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 processing such as color correction and gradation conversion, and are converted into image signals Sy representing color-separated images of Y, K, M, and C versions, respectively. , Sk, Sm, Sc. The image signals Sy, Sk, Sm, and Sc are each converted into digital signals by an A/D converter 109 and provided to a dot generator 110. Digital image signals Sy, Sk,
Sm and Sc are gradation level signals that express 256 gradations using, for example, 8 bits.

When recording halftone images of Y, K, M, and C versions on recording film RF, dot generator 110 generates halftone dot signals Sd based on digital image signals Sy, Sk, Sm, and Sc. Occur. This halftone signal Sd is
AOM (acousto-optic modulator) 111 allows laser light source 1
On/off control of the laser beam L emitted from 12 is performed. The laser beam L that has passed through the AOM 111 is directed to the recording head 11.
3, the light is focused and exposes the recording film RF wound around the output drum 102. As a result, halftone images of each of the Y, K, M, and C versions are recorded on the recording film RF. Note that during this recording operation, the output drum 102 rotates at a constant speed in the θ direction, and the recording head 113 is also moved at a constant speed in a direction parallel to the rotation axis of the output drum 102 by the feed screw 114.

When creating a calibration image, the digital image signals Sy, Sk, Sm, Sc are sent to the color scanner 10.
0 to the calibration image recording device 200. The calibration image recording device 200 includes an interface circuit 201,
Color calculation circuit 202, dot generator 203, and K
The plate signal synthesis circuits 204y, 204m, 204c, the filtering circuits 205y, 205m, 205c, and the D/
A converter 206, laser light sources that emit laser beams of B, G, and R colors (not shown), and AOM units 207y, 207m, which control on/off of the laser beams of each color.
207c, a reflecting mirror 208a, dichroic mirrors 208b and 208c, an exposure head 209, and a drum 210.

In the calibration image recording device 200, digital image signals Sy, Sk, Sm, and Sc are provided to a color calculation circuit 202 via an interface circuit 201. This color calculation circuit 202 has a function of performing color correction and gradation correction of each digital image signal Sy, Sk, Sm, and Sc so that the color tone of the calibration image matches the color tone of the image on the printed material.

Image signal S corrected by color calculation circuit 202
y1, Sk1, Sm1, Sc1 are input in parallel to the dot generator 203 for 4 channels to generate the halftone dot signal S.
dy, Sdk, Sdm, and Sdc. These halftone dot signals Sdy, Sdk, Sdm, and Sdc are binary signals having an H level or an L level. For example, if the H level is high, exposure is performed, and if the L level is not, the exposure is performed. Therefore, the halftone dot signals Sdy, Sdk, Sd
Halftone dots are formed based on the arrangement of m and Sdc, and these halftone dots are equivalent to the halftone dots recorded by the color scanner 100. In this embodiment, as will be described later, the color sensitive material is exposed using 10 exposure beams at the same time, so each halftone dot signal Sdy, Sdk, Sdm, and Sdc controls each of the 10 exposure beams. It is configured as a 10-bit signal.

Note that the screen line number and screen angle of the halftone image for each of the Y, K, M, and C versions are set to predetermined values by the dot generator 203, respectively. A method for arbitrarily setting the screen line number and screen angle of a halftone image is described in, for example, Japanese Patent Laid-Open No. 55-6393,
It is detailed in Japanese Patent Application Laid-open No. 137473/1983.

Chromatic color halftone signals Sdy, Sdm, Sdc
are respectively input to the K version signal synthesis circuits 204y, 204m, and 204c together with the K version halftone dot signal Sdk. Each K version signal synthesis circuit 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 AND of the two input signals. Sdm1
, Sdc1. As a result, in the area that should be the halftone dots of the K plate, the three colors Y, M, and C are all colored and become black, and the halftone dots of the four colors 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 synthesis circuit are detailed in Japanese Patent Application No. 1-285823 filed by the present applicant.

K version signal synthesis circuit 204y, 204m, 2
The 10-bit composite halftone dot signals Sdy1, Sdm1, and Sdc1 generated in step 04c are input to filtering circuits 205y, 205m, and 205c, respectively.
Here, by simulating the diffusion of ink around the halftone dot, 10-bit diffusion simulation halftone signals Sdy2, Sdm2,
Sdc2 is output. Note that the filtering circuit 20
The configurations and processing contents of 5y, 205m, and 205c will be further described later.

[0020] Each diffusion simulated halftone signal Sdy2, Sdm2,
Sdc2 is converted into an analog signal by the D/A converter 206, and sent to the AOM units 207y, 207m,
207c, respectively. Note that each of the AOM units 207y, 207m, and 207c is composed of a 10-channel AOM, and controls on/off of 10 exposure beams. Also, AOM unit 207y
, 207m, 207c are blue, green, respectively.
Controls exposure beams B, G, and R for each color of red. A
The exposure beams B, G, and R modulated by the OM units 207y, 207m, and 207c are apparently combined into 10 beams by the reflection mirror 208a and dichroic mirrors 208b and 208c, and then imaged into a light spot by the exposure head 209. The color photosensitive material PF wound on the drum 210 is exposed to light, and a calibration image is recorded on the color photosensitive material PF. Note that during this exposure, the drum 210 is φ
It rotates at a constant speed in the direction, and moves at a constant speed in the direction parallel to the axis of rotation.

[0021] Thus, in this scanner system,
The filtering circuits 205y, 205m, and 205c create diffusion simulation halftone signals Sdy2, Sdm2, and Sdc2 that simulate the diffusion of ink around the halftone dots during printing;
Since the calibration image is recorded based on these signals, there is an advantage that the image quality can be confirmed in the calibration image while simulating the diffusion of ink around the halftone dots during printing.

Furthermore, K version signal synthesis circuits 204y, 20
4m, 204c, image signals Sdy1, Sdm1, Sdc are expressed by overlapping the halftone dots of the K version with other halftone dots.
1, so for example, like silver halide photographic material, Y
, M, and C color forming layers, a calibration image can be directly recorded based on these signals. The above processing has the advantage that a calibration image can be created directly from an image signal, instead of creating a calibration image after recording a color separation halftone image on a film or the like as in the conventional method. In other words, even if there is a portion to be corrected in the proof image, there is no need to re-create the color separation halftone image on the film.

Next, the configuration and operation of the filtering circuit will be explained in detail. 2 and 3 are block diagrams showing the internal configuration of the Y version filtering circuit 205y. Other versions of filtering circuit 205m, 205
Regarding the configuration of c, the filtering circuit 20 for Y version
5y, and the explanation will be omitted. Note that the composite halftone dot signal Sdy1 input to the filtering circuit 205y is a 10-bit signal as described above, but here, in order to simplify the diagram and explanation, five exposure beams are used simultaneously. It is assumed that a color photosensitive material is exposed to light using the same method, and that the composite halftone dot signal Sdy1 is a 5-bit signal.

The filtering circuit 205y includes first and second line ring memories 300, 301, first and second latch circuit groups 302, 303, first to fifth arithmetic circuits 304, 305, 306, 307,30
8. In the filtering circuit 205y, the input composite halftone dot signal Sdy1 is divided into dot signals Sdy11, Sdy12, and Sdy1 arranged in the sub-scanning direction.
It is applied to the first line ring memory 300 every dy13, Sdy14, and Sdy15. First line ring memory 300 (same as second line ring memory 301)
is the composite halftone dot signal Sd for one scan of five exposure beams.
5×n (n is the number of dots in the main scanning direction) to store y1
In the bit memory, every time one 5-bit composite halftone signal Sdy1 is input, the stored composite halftone signal Sdy
1 in the main scanning direction (rightward in the figure) and outputs 5 bits of the rightmost composite halftone dot signal Sdy1 to the outside.

The composite halftone dot signal Sdy1 output from the first line ring memory 300 is input to the second line ring memory 301. Second line ring memory 3
01, similar to the first line ring memory 300,
Composite halftone signal Sdy1 for one scan of five exposure beams
The stored composite halftone dot signal Sdy1 is shifted in the main scanning direction every time the composite halftone dot signal Sdy1 output from the first line ring memory 300 is input. Then, the composite halftone dot signal Sdy1 is outputted to the outside from the rightmost end.

The composite halftone dot signal Sdy1 output from the second line ring memory 301 is sent to the first latch circuit group 3.
Given to 02. The first latch circuit group 302 has three 5-digit latch circuits connected in series so that the 5-bit composite halftone dot signal Sdy1 can be stored and held in three stages in the order of input, and when an external clock is applied, each latch Update the memory 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
When the signal is input to the second line ring memory 301, it is also provided to the second latch circuit group 303 at the same time. The second latch circuit group 303 uses its dot signal Sdy1
1, Sdy12 can be stored in 3 stages in input order 2
Three digit latch circuits are serially connected, and when a clock is applied from the outside, the memory contents of each latch circuit are updated. This clock is synchronized with the timing at which the composite halftone dot signal Sdy1 is input to the first line ring memory 300.

The operations of the first and second line ring memories 300, 301 and the first and second latch circuit groups 302, 303 configured in this manner will be described next. When the composite halftone dot signal Sdy1 is input to the filtering circuit 205y, each dot signal Sdy11 to Sdy15 is
First, it is input to the first line ring memory 300, and 5
Composite halftone signal Sd for the first scan with one set of book scanning lines
y1 is stored in the first line ring memory 300. Subsequently, the composite halftone dot signals Sdy1 for the second scan are sequentially input to the first line ring memory 300, but the composite halftone dot signals Sdy1 for the second scan are all stored in the first line ring memory 300. At this time, the second line ring memory 301 stores the composite halftone dot signal Sdy1 for the first scan.

After that, the composite halftone dot signal Sdy for the third scan is
1 is input to the first line ring memory 300, but every time one composite halftone signal Sdy1 is input, the first composite halftone signal Sdy1 is output from the second line ring memory 301. is stored in the first latch circuit group 302, and simultaneously stored in the first line ring memory 30.
1, the first dot signals Sdy11 and Sdy12 in the first line ring memory 301 are output, and the second
is stored in the latch circuit group 303.

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

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

That is, as shown in FIG. 4, in the entire image area indicated by the coordinate value x in the sub-scanning direction and the coordinate value y in the main scanning direction, first, the x coordinate value is 1 to 7, and the y coordinate value is is 1~
Each dot signal in area R11 where the number is 3 is then applied to area R12 where the x coordinate value is 1 to 7 and the y coordinate value is 2 to 4.
Each dot signal of the first latch circuit group 302 and the second
This is extracted by the latch circuit group 303.

After that, the extraction area is shifted by one signal in the y direction, and the x coordinate value is 1 to 7, and the y coordinate value is n-
Dot signals up to region R1 (n-2), which is 2, n-1, n, are extracted. Next, the x coordinate value is 6 to 12,
The dot signal of area R21 whose y coordinate value is 1 to 3, x
The dot signals of the area R22 having coordinate values of 6 to 12 and y coordinate values of 2 to 4 are extracted in order. In this way, dot signals of a 7×3 area are sequentially extracted for the entire image area. Each dot signal of the extracted area is sent to the first to fifth arithmetic circuits 304 to 30 for each area.
given to 8.

[0034] Hereinafter, the first to fifth arithmetic circuits 304 to
308 will be explained in detail. First arithmetic circuit 304
weights the 3×3 elements by applying a weighting function (spatial filter) that is a 3×3 matrix shown in FIG. and three sets of adder circuits that add the outputs from each multiplier circuit (multiplier circuit groups 400a, 400b, 4
00c, adder circuits 401a, 401b, 401c), and an adder circuit 402 that adds the outputs from each adder circuit 401a, 401b, 401c. The nine multiplier circuits composed of three multiplier circuit groups 400a, 400b, and 400c each have weight function elements A to
The values of I are each input, and the values of the three latch circuits from the top of the first latch circuit group 302 described above are input to the other end.

With this 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 indicate the values of each element A to I of the weighting function. In addition, S11, S21,...
It is shown as V.

The second arithmetic circuit 305 has the same configuration as the first arithmetic circuit 304, and one end of each multiplier circuit has latch circuits of the second to fourth digits of the first latch circuit group 302. Each value is entered. With this configuration, a spread dot signal Sdy22 shown below 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 the first arithmetic circuit 304, and a first latch circuit group 3 is provided at one end of each multiplier circuit.
The values of the latch circuit from the 3rd digit to the 5th digit of 02 are respectively input. With this configuration, a spread dot signal Sdy23 shown below 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, and has a first latch circuit group 3 at one end of each multiplication circuit.
4th and 5th digits of 02 and second latch circuit group 303
The values of the latch circuits in the first digit are respectively input. With this configuration, the diffused dot signal Sdy shown below
24 will be output. Sdy24 = HA・S41 + HB・S51
+ HC・S61 + HD・S42 +
HE・S52 + HF・S62 + HG・S43
+ HH・S53 + HI・S63 Here, S61
, S62, and S63 indicate the values of the latch circuits in the first digit of the second latch circuit group 303.

The fifth arithmetic circuit 308 has the same configuration as the first arithmetic circuit 304, and the fifth digit of the first latch circuit group 302 and the second latch circuit group 303 are connected to one end of each multiplier circuit. The latch circuit values of the first and second digits are respectively input. With this configuration, a spread dot signal Sdy25 shown below is output. Sdy25 = HA・S51 + HB・S61
+ HC・S71 + HD・S52 +
HE・S62 + HF・S72 + HG・S53
+ HH・S63 + HI・S73 Here, S71
, S72, and S73 indicate the values of the second digit latch circuits of the second latch circuit group 303.

In this way, weighted integration processing for 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. In addition, the diffused dot signal Sdy21
~Sdy25 forms a diffusion simulated halftone signal Sdy2.

[0041] Below, the filtering circuits 205y, 20
How the combined halftone dot signals Sdy1, Sdm1, and Sdc1 input to the filtering circuits 205y, 205m, and 205c change by the weighted integration processing of 5m and 205c will be explained. Before the explanation, let us introduce the halftone dot area HD, the dots forming the halftone dot, and the composite halftone signal Sdy1.
, Sdm1, and Sdc1 will be explained using 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, if the screen angle is 0°, the halftone area HD is composed of approximately 23×23 dots. The number of dots obtained in the sub-scanning direction by one main scan is 10 (as shown in Figures 2 and 3), since the color sensitive material is exposed using 10 exposure beams simultaneously as described above. In the example shown, there are 5). Therefore, one halftone dot is formed in the sub-scanning direction by two or more main scans (approximately 2.3 times). Each dot has a one-to-one correspondence with each dot signal forming the composite halftone dot signals Sdy1, Sdm1, and Sdc1.

These composite halftone dot signals Sdy1, Sdm1
, Sdc1 is simply subjected to 3×3 weighted integration processing in the input order, as mentioned above, one halftone dot area has more dots in the sub-scanning direction than the number of dots in the sub-scanning direction obtained in one main scan. Since it is composed of the number of dots in the scanning direction, the main scanning boundary line inside the halftone dot (line segment K1K2 and line segment K3 in Figure 6)
The weighted integral processing is applied to the dots on the upper halftone dot (corresponding to K4) as a peripheral part of the halftone dot. On the other hand, the filtering circuits 205y, 205m, 205
In c, as mentioned above, 12 (
7) After each dot signal corresponding to each dot is once extracted, 3×3 weighted integration processing is performed, so that processing can be performed without misrecognizing dots even on the main scanning boundary line.

FIG. 7 shows a dot signal group G1 based on the composite halftone signal Sdy1 input to the filtering circuit 205y.
FIG. 12 is an explanatory diagram showing a comparison between the spread dot signal group G2 based on the spread simulated halftone dot signal Sdy2 outputted from the filtering circuit 205y; In FIG. 7, the composite halftone dot signal S
The dot signal group G1 based on dy1 has a halftone area ratio of 50%.
For example, exposure is performed with a dot signal of H level (=1), and exposure is not performed with a dot signal of L level (=0). However, to simplify the explanation, the dot configuration of the halftone area HD in FIG. 7 is 23×2.
Not 3. When the dot signal group G1 based on this composite halftone signal Sdy1 is input to the filtering circuit 205y, the diffusion simulated halftone signal S
A diffused dot signal group G2 based on dy2 is output. The diffused dot signal group G2 is a multilevel signal, and the level becomes lower as it approaches the periphery of the halftone dot.

This diffusion simulated halftone signal Sdy2 is converted into an analog signal by the D/A converter 206 as described above, but at this time, the maximum level value (in the example of FIG. 7, the value 1)
In step 6), the voltage level generated when the binary level value is 1 is given. The first quadrant of FIG. 8 shows the voltage level after D/A conversion of the signal in row k of the diffused dot signal group G2 shown in FIG.
The A converter 206 outputs an analog signal in which the periphery of the halftone dot has been smoothed.

The voltage signal after D/A conversion is applied to the AOM unit 207y as described above, and the AOM unit 207y modulates the exposure beam according to the voltage signal, and also varies the transmittance of the beam. The exposure beam is then 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 the same figure, and the density of the image as a result of exposure is shown in the fourth quadrant of the same figure. In FIG. 8, it can be seen that the halftone dots indicated by two-dot chain lines are based on the dot signal group G1, whereas the diffused dot signal group G2 produces halftone dots with rounded edges. For this reason, as a result of exposure, output is produced in which the periphery of the halftone dots is blurred.

Therefore, the calibration image created by the calibration image recording apparatus 200 of this embodiment simulates the diffusion of ink around the halftone dots during actual printing.
The image quality of the proofing image and the image quality of the printed matter printed by the color scanner 100 are well matched. Therefore, the image quality can be confirmed using the proof image while simulating the diffusion of ink around the halftone dots during printing. Note that the diffusion simulated halftone dot signals Sdy1, Sdm1,
The rounded shape of the halftone dot shown by Sdc1 changes depending on the value of the weighting function shown in Figure 5, so it depends on the printing pressure during printing and the amount of residual dampening water left on the halftone dot of the printing plate. By empirically changing the value of the weighting function accordingly, it is possible to more appropriately simulate the diffusion of ink around halftone dots during printing, the degree of which changes depending on the printing pressure and the amount of residual dampening water. Can be done.

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 the first embodiment, and a calibration image recording device having a different configuration from the first embodiment. The calibration image recording device 200 in the first embodiment has a configuration in which filtering circuits 205y, 205m, and 205c are provided after the K-plate signal synthesis circuits 204y, 204m, and 204c. In the image recording device for calibration, the K version signal synthesis circuit 204y, 204m,
This is a configuration in which a filtering circuit is provided before 204c.

FIG. 9 shows such a calibration image recording device 30.
0 is a diagram showing the configuration of 0. As shown in FIG. 9, digital image signals Sy, S output from the color scanner 100
k, Sm, and Sc are connected to the same color calculation circuit 20 as in the first embodiment via the same interface circuit 201 as in the first embodiment.
given to 2. The image signals Sy1, Sk1, Sm1, Sc1 corrected by the color calculation circuit 202 are converted into serial signals by the parallel/serial converter 301, and then input to the dot generator 303 to generate the halftone dot signal Sd.
y, Sdk, Sdm, and Sdc. The halftone dot signals Sdy, Sdk, Sdm, and Sdc are input to a filtering circuit 305, which simulates the diffusion of ink around the halftone dots in the same way as in the first embodiment, and uses a 10-bit diffusion simulation network for each. Point signals SdyA, SdkA, SdmA
, SdcA are output.

[0049] The diffusion simulated halftone dot signals SdyA, SdkA
, SdmA, SdcA are serial/parallel converters 3
06, and the same K as in the first embodiment.
The signals are input to plate signal synthesis circuits 204y, 204m, and 204c, respectively. K version signal synthesis circuit 204y, 204m,
Combined halftone dot signals SdyB and SdmB generated at 204c
, SdcB are the same D/A converters 206 as in the first embodiment.
The signals are respectively converted into analog signals and provided to the same AOM units 207y, 207m, and 207c as in the first embodiment. In this manner, the color photosensitive material PF wound on the drum 210 is exposed to light in the same manner as in the first embodiment, and a calibration image is recorded on the color photosensitive material PF.

In the second embodiment configured as 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 creates a You can check the image quality by simulating the diffusion of ink around the halftone dots. Moreover, in this embodiment, data is transferred to the filtering circuit 305 serially, so there is no need to arrange three filtering circuits in parallel as in the first embodiment, and a compact configuration can be achieved.

In addition, in this embodiment, the K version signal synthesis circuit 2
04y, 204m, and 204c, the filtering circuit 305 is provided before the chromatic color halftone signals Sdy, Sdm, and Sdc, as well as the K version halftone signal Sdk. Smoothing processing is performed on the periphery. Therefore, even if a halftone dot of the K plate partially overlaps with a halftone dot of a chromatic color, it is possible to simulate the diffusion of ink around the halftone dot of the K plate, which corresponds to the boundary between the two. . Diffusion of the black layer on the chromatic color layer during printing is not as remarkable as when black is directly placed on the color photosensitive material PF, but if such diffusion is considered a problem, the structure of this embodiment can be used. , the diffusion of ink around the halftone dots of the K plate can be sufficiently simulated.

[0052] In the first and second embodiments,
Color photosensitive material PF as a photosensitive recording medium as a recording means
Although the configuration is such that an image is optically recorded thereon, an electrophotographic configuration may be adopted instead. That is, an electrostatic latent image is obtained by irradiating a charging drum with a laser beam modulated according to a diffusion simulation signal in which the peripheral area of each halftone dot of a halftone image has been smoothed. It may be configured to record a color image by applying toner. When scanning and exposing a color image for calibration using an electrophotographic configuration, only one type of laser may be used (e.g., semiconductor laser, He-Ne laser, Ar
If you use toner in the four colors of Y, M, C, and K (laser, etc.), or use a photosensitive material pre-colored in each of the four colors, the Y, M, C, and K four versions can be exposed independently. do it.

Although several embodiments of the present invention have been described above, the present invention is not limited to these embodiments in any way, and within the scope of the gist of the present invention,
Of course, it can be implemented in various ways.

[0054]

According to the color image recording apparatus of the present invention as described above, it is possible to record a color image that simulates the diffusion of ink around halftone dots during printing. Therefore, the quality of the printed image can be confirmed using the color image while simulating the diffusion of ink around the halftone dots during printing.

[Brief explanation of drawings]

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

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

FIG. 3 is a block diagram showing other parts of the internal configuration of the filtering circuit 205y.

FIG. 4 is an explanatory diagram showing a region of dot signals 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 the relationship between the halftone dot area HD and the dots forming the halftone dot.

FIG. 7 shows a dot signal group G1 based on the composite halftone dot signal Sdy1 inputted to the filtering circuit 205y and a diffused simulated halftone dot signal Sd outputted from the filtering circuit 205y.
FIG. 3 is an explanatory diagram showing a comparison between the spread dot signal group G2 and the spread dot signal group G2 based on y2.

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

FIG. 9 is a schematic configuration diagram showing the configuration of a calibration image recording device for a scanner system as a second embodiment of the present invention.

[Explanation of symbols]

100 Color scanner 200 Calibration image recording device 203 Dot generator 204y, 204m, 204c K version signal synthesis circuit 2
05y, 205m, 205c Filtering circuit 2
07y, 207m, 207c AOM unit 209
Exposure head 300, 301 Line ring memory 302, 303
Latch circuit group 304, 305, 306, 307, 308 Arithmetic circuit PF Color sensitive material Sdy, Sdk, Sdm, Sdc Dot signal Sdy1
, Sdm1, Sdc1 Combined halftone dot signals Sdy2, Sd
m2, Sdc2 Diffusion simulated halftone signal 303 Dot generator 305 Filtering circuit

Claims (3)

[Claims] 1. A color image recording device that records 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, comprising:
a halftone signal generating means for creating a binary halftone signal representing each color separation image as a halftone image based on the image signal; a diffusion simulated halftone signal creating means for creating a multivalued diffusion simulated halftone signal in which the surrounding area of each halftone dot is smoothed; and a value of the diffuse simulated halftone signal created by the diffusion simulated halftone signal creating means. 1. A color image recording apparatus, comprising: recording means for recording a halftone image on the recording medium at a recording level based on the recording level. 2. The color image recording apparatus according to claim 1, wherein the diffusion simulated halftone signal creation means includes spatial filter signal output means for outputting a predetermined weighted signal, By calculating the extracted halftone dot signals sequentially extracted from the halftone dot signals created by the point signal generation means, a diffusion simulated halftone dot signal is created in which the periphery of each halftone dot of the halftone image is smoothed. A color image recording device comprising a calculation means. 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 dot signal creation means comprises a halftone dot signal generation means. At least two scans of the halftone dot signals outputted from are temporarily stored, and the N-1 halftone dot signals of the subsequent second scan are added to the first scan of the two stored scans, and then sequentially A color image recording device comprising addition halftone signal output means for outputting an extracted halftone signal to a calculation means.