JP3226224B2 - Image processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus such as a digital copying machine, an image scanner, a printer, and a facsimile.

[0002]

2. Description of the Related Art In recent years, for example, in digital copying machines,
An image processing method has been proposed which reproduces color information of a document as a monochrome image to provide a visual effect similar to that of reproducing a color image. In this method, first, color information of a document is converted into a color signal by a photoelectric conversion element such as a color CCD, and an area determined to be the same color by the color signal is replaced with a predetermined graphic pattern signal, and reproduced in a single color. Then, a monochrome image is reproduced.

Hereinafter, this type of image processing apparatus will be described with reference to FIGS.

First, an overall configuration of a digital copying machine which is a conventional image processing apparatus will be described with reference to FIG.

The digital copying machine includes an image reading section 101 for reading a full-color original 100, an image processing section 102 for processing a read image, and an image processing section 102.
And a laser beam printer 103 for printing the output of the apparatus, and a CPU circuit unit 1 for controlling the operation of the entire apparatus.
04 is provided.

In this digital copying machine, a document 100 is exposed by an exposure lamp (not shown), and a reflected color image is picked up by a color CCD image sensor 101b. further,
A / D conversion converter 10 converts the obtained analog image signal.
1c, the digitized full-color image signal is processed and processed by the image processing unit 102, and the printer 10
3 to obtain a monochrome image.

Here, the color information of the original 100 is transmitted to the CCD sensor 10 via the lens 101a of the image reading unit 101.
1b, each line is represented by R (Red: red),
G (Green: green), B (Blue: blue) 4 each
Read at 00 dpi. In the image processing unit 102, shading correction is performed by a shading correction circuit 102a to generate R, G, and B 8-bit image data. The data processing unit 102b determines the color of the read image data and converts the color into a pattern corresponding to the color.
Convert to density data and generate output data.

The printer 103 has a control circuit such as a motor for transporting transfer paper and the like, a laser recording unit for writing output data input from the image processing unit 102 to a photosensitive drum, and a development control circuit for developing. are doing. Also, C
The PU circuit unit 104 includes a CPU 104a, a ROM 104
b, and a RAM 104c, and an image reading unit 101,
It controls the image processing unit 102, the printer 103, and the like, and comprehensively controls the sequence control of this apparatus.

Next, the configuration and operation of the data processing unit 102b will be described with reference to FIGS. 17 is a block diagram showing the configuration of the data processing unit 102b in FIG. 16, and FIG. 18 is a block diagram showing the configuration of the color determination unit 111 in FIG. FIG. 19 is a block diagram showing the configuration of the pattern generator 114 and the address controller 115 in FIG.

In FIG. 17, a data processing unit 102b in FIG. 16 includes a luminance signal generation unit 110, a color determination unit 111,
Selector 112, multiplier 113, pattern generator 11
4 and an address control unit 115. As shown in FIG. 18, the color determination unit 111
/ Mid / min detector 120, subtractors 121 and 12
2, hue detection unit 123, window comparator 124,
125, and an AND gate 126. Further, as shown in FIG. 19, the pattern generator 1 shown in FIG.
Reference numeral 14 denotes a ROM 130, and an address control unit 115
Are the main scanning counter 131, the sub-scanning counter 133 and N
It is composed of OR gates 132 and 134. Next, the operation of the digital copying machine configured as described above will be described.

[0011] The luminance signal generator 110 receives the input R,
An average value for each of the G and B data is calculated using an adder and a multiplier to generate a luminance signal S110. The luminance signal S110 is supplied to the input side A of the selector 112. The color determination unit 111 detects a color component on a document for performing image processing. Hereinafter, an outline of the color detection processing will be described with reference to FIG.

The input R, G, and B data are each 8-bit data, have information of a total of 224 colors, and first, a max / mid / min detection unit 120 for determining the magnitude thereof.
Is input to This is because, by comparing each input data with a comparator, the max value (maximum value), mi
The d value (intermediate value) and the min value (minimum value) are obtained, and each value is output. Further, each output value of the comparator is simultaneously output as a rank signal.

It is known that a color space is represented by three dimensions of saturation, lightness, and hue, as is known in a Munsell solid or the like. R expressed in this three-dimensional color space,
Each data of G and B is converted into a plane, that is, a two-dimensional color space. In this conversion processing, max / mid / mi
In order to reduce the achromatic component from the max value and the mid value output from the n detecting unit 120, the min value is subtracted from the max value and the mid value by the subtractors 121 and 122, and is supplied to the hue detecting unit 123 together with the rank signal. The converted plane is divided into six from 0 ° to 360 ° as shown in FIG. 20, and the order of the sizes of the input R, G, and B, that is,
R>G> B, R>B> G, G>B> R, G>R> B, B
>G> R and B>R> G.

The hue detection unit 123 stores in advance values corresponding to the angle of the plane shown in FIG. 20, and receives the input order signal, (max-min) value, and (mid-m).
The corresponding hue value is output according to the in) value.

The hue values output in this manner are then input to window comparators 124 and 125.
The setting of the reference comparison values of the comparators 124 and 125 is performed by the CPU 104a. This reference value is obtained by converting the originally matching hue value into a CP value using data input means (not shown).
After a desired offset is given by U104a, it is set to comparators 124 and 125. Assuming that the setting reference value is a1, the comparator 124 outputs “1” for the input hue value when (input hue value)> (a1). Similarly, when the setting reference value is a2, the comparator 125 is configured to output “1” when (input hue value) <(a2) with respect to the input hue value. Therefore, when (a1) <(input hue value) <(a2), “1” is output from the subsequent AND gate 126 to the input side S of the selector 112.

On the other hand, the pattern generator 11 shown in FIG.
4 includes a ROM 130 in which pattern dot data is stored in advance at an address including an upper address and a lower address, as shown in FIGS. 21A and 21B (see FIG. 19). Then, the address control unit 115
A read address of M130 is generated.

Referring to FIG. 19, the main scanning counter 131 of the address control section 115 synchronizes with the horizontal synchronizing signal HSYNC as shown in FIG.
And outputs the upper address of the ROM 130. The sub-inspector counter 133 outputs a horizontal synchronizing signal HSY in synchronization with a signal ITPO that becomes “L” level when the image reading unit 101 shown in FIG.
Using NC as the count, the lower address of ROM 130 is output.

The dot data designated by the upper address and the lower address and read from the ROM 130 is multiplied by the min value (darkest signal) output from the color discriminator 111 by the multiplier 113, and the multiplication result is selected by the selector. It is output to the input side B of 112.

Therefore, the selector 112 sets the reference value a
When 2 <input hue value <reference value a1, luminance signal S110
Is selected. In other cases, the output signal of the multiplier 113 is selected and output to the drive circuit of the printer 103 shown in FIG.

In this way, even if the original is composed of a plurality of colors, it is possible to identify the colors by copying with a single developing machine by converting the color portions into patterns.

[0021]

However, in the above conventional example, as shown in FIGS.
Since the size and cycle of the dot pattern of 130 are constant, when thin lines such as a color-coded line graph are patterned, it is difficult to identify colors by the pattern, and the recorded image becomes extremely unclear. there were.

The present invention has been made in view of the above-mentioned conventional problems, and provides an excellent image processing apparatus capable of easily distinguishing a color by a pattern even with a thin line such as a color-coded line graph and obtaining a clear recorded image. The purpose is to:

[0023]

In order to achieve the above object, an image processing apparatus according to the present invention has the following arrangement.

In the first invention, a color discriminating means for discriminating a color of an input image, a line width detecting means for discriminating the area width of the color, and a color discriminating means for each color according to the discrimination result by the color discriminating means.
A first signal generating means for generating a first signal of a fixed density, and a determination for each color according to a result of the determination by the color determining means.
A second signal generating means for generating a second signal representing the obtained pattern image, and a density ratio between the first signal and the second signal according to a detection result by the line width detecting means.
And a combining means for combining changed, the synthesizing means, on
The smaller the width detected by the line width detecting means,
The density ratio of the first signal is high, and the density ratio of the second signal is high.
Lower, and the larger the detected width, the larger the first
And the density ratio of the second signal is reduced.
It is characterized in that it is raised and combined .

[0025]

[0026] The second invention is a color discriminating means for discriminating the color of the input image, a position detecting means for determining the position of the contour in the region of the color, in accordance with the discrimination result by the color determination means for each color A first signal generating means for generating a first signal of a fixed density determined in accordance with the first and second colors, and a second signal representing a pattern image determined for each color in accordance with a result of the determination by the color determining means.
A second signal generating means for generating a signal from the first signal and a first signal from the first signal in accordance with a detection result by the position detecting means from the contour.
Combining means for combining the said second signal by changing the concentration ratio
And the combining means detects the position by the position detecting means.
The closer the position from the contour is, the darker the first signal is.
A high density ratio and a low density ratio of the second signal.
And the farther the position from the detected contour is, the more the first
And the density ratio of the second signal is reduced.
It is characterized in that it is raised and combined . According to a third aspect of the present invention, there is provided a conversion means for detecting a color area in an input color image and converting the color area into a pattern image corresponding to a color, detecting a color outline in the input color image, and detecting the outline. Generating means for generating a border image at a portion; and combining means for combining the pattern image from the converting means and the border image from the generating means at a ratio according to a distance from a color contour. Further, in the third invention, the synthesizing unit includes:
It is desirable that the composition be performed such that the density of the border image becomes higher as it is closer to the contour, and the density of the border image becomes lower as it is farther from the contour. In addition, it is desirable to perform synthesis such that the density of the pattern image decreases as the distance from the contour decreases, and the density of the pattern image increases as the distance from the contour increases.

[0027]

In the first invention, the synthesizing means includes a line width detecting means.
The narrower the detected width, the smaller the fixed darkness determined for each color.
The density ratio of the first signal is high, and is determined for each color.
The density ratio of the second signal representing the pattern image
The larger the detected width, the greater the density of the first signal
Lowering the ratio and increasing the density ratio of the second signal
You. In this way, when the line width is thin, the output is performed at a fixed density set for each color, and as the line width increases, the ratio of the fixed density can be reduced to increase the pattern density ratio. Outputs high.

In the second invention, the synthesizing means includes a position detecting means.
The closer to the position from the contour detected by the step, the more
Increase the density ratio of the first signal, which is the fixed density
And a second signal representing a pattern image determined for each color.
And lower the density ratio of
The farther the distance, the lower the density ratio of the first signal and the second signal.
Combine with a high concentration ratio of the signal. As a result, the fixed density ratio can be increased closer to the contour, and the density ratio of the pattern can be increased as the pattern goes inward from the contour portion. The thin line is output with a higher fixed density ratio. In the third aspect, the synthesizing unit synthesizes the pattern image from the converting unit and the border image from the generating unit at a ratio according to the distance from the color outline. Thereby, the converted pattern image can be bordered, and when the size of the color region is not enough to output the pattern image, at least the outline is output in an identifiable state.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the image processing apparatus according to the present invention.
FIG. 17 is a block diagram of a main part of a digital copying machine showing an embodiment of the present invention, in which elements common to FIG. 16 are denoted by the same reference numerals.

This digital copying machine differs from the conventional apparatus shown in FIG. 16 in that a data processing unit having a function different from that of the conventional data processing unit 102b is provided.

This data processing unit, as shown in FIG.
It includes a luminance signal generation unit 110, a selector 112, a multiplier 113, a pattern generation circuit 114, and an address control circuit 115 having the same configuration as the data processing unit 102b in FIG. Part 20
One. Further, on the output side of the color discriminating unit 201, via the fine line detecting unit 203, a fixed density selecting unit 204
And a pattern density selection unit 205, and the output sides of the fixed density selection unit 204 and the pattern density selection unit 205 are connected to an adder (signal combining unit) 206. Then, the luminance signal S1 output from the luminance signal generation unit 110
10 is supplied to the color determination unit 201.

The output of the pattern generation circuit 114 and the output of the color discrimination section 201 are connected to selectors 207 and 209, and the output side of the selector 207 is connected to the multiplier 113. The luminance signal generation unit 110, the selector 112, the multiplier 113, the pattern generation circuit 114, the address control circuit 115, and the selector 207 constitute a graphic pattern output unit. In addition, fixed concentration selection unit 2
04, the selector 209 and the register 208
And a selector 112 is connected to an input side of the pattern density selection unit 205. FIG. 2 shows the configuration of the color determining unit 201.

In FIG. 2, the color discriminating unit 201 is provided with
Max / mid / mi having the same configuration as the conventional device shown in FIG.
n detector 120, subtracters 121 and 122, hue detector 1
23, comparators 210 and 211, registers 212 and 213, AND gates 214 and 215, A
ND gate 216, color determination circuit 217, and inverter 2
16. The luminance signal S110 output from the luminance signal generation unit 110 shown in FIG.
11.

On the other hand, the fine line detector 203 shown in FIG. 1 is configured as shown in FIG.

That is, the AND gate 215 shown in FIG.
And an output of the inverter 216, a 3 × 3 narrowing circuit 220, a 5 × 5 narrowing circuit 221, a 7 × 7 narrowing circuit 222, a 9 × 9 narrowing circuit 223, and a 3 × 3 thickening circuit. 224, 5 × 5 fattening circuit 225, 7 × 7 fattening circuit 2
26, 9 × 9 fattening circuit 223, exclusive OR circuit (hereinafter referred to as XOR gate) 228 to 230, and AND
It is composed of gates 231 to 234. As shown in FIG. 7, each of the narrowing circuits 220 to 223 is configured as shown in FIG.
, The white signal S215, which is the output of the AND gate 215, is taken in, and FIFO memories 240 to 243, XAND gates 244 to 247, AND gate 248, flip-flops 249 to 256, XOR gates 257 to 260,
And AND gates 261-263. Also,
As shown in FIG. 8, each of the fattening circuits 224 to 227
IFO memories 270-273, OR gate 274, flip-flops 275-278, and NOR gate 279
It is composed of

FIG. 9 shows the configuration of the fixed density selection unit 204 and the pattern density selection unit 205 in FIG.

In FIG. 9, the fixed density selecting section 204
The fixed density signal S20 output from the selector 209 in FIG.
8 and a coefficient selection signal S2 output from the thin line detection unit 203.
03, the coefficient register 280, the selector 28
1 and a multiplier 282, and the pattern density selection unit 205 captures the graphic pattern signal S112 and the coefficient selection signal S203 output from the selector 112,
Coefficient register 290, selector 291 and multiplier 292
It is composed of

Next, the operation of the image processing apparatus configured as described above, particularly, the operation of the data processing unit will be described.

The shading correction circuit 10 shown in FIG.
The 8-bit data of R, G, and B that have been subjected to white correction and black correction, which are outputs of 2a, are supplied to the luminance signal generation circuit 110 and the color determination unit 201. In the luminance signal generation unit 110, as in the related art, a luminance signal S110, which is an image over the entire wavelength region not subjected to color separation, that is, a black-and-white image, is converted from an image read and color-separated by the color CCD image sensor 101b. Has been created. This is because the printer 103 of this embodiment performs only monochrome printing.

The color discriminating unit 201 discriminates predetermined color components (chromatic / achromatic, white / other colors) on the document for performing the image processing in this embodiment. The color determination unit 201 uses a hue signal for color detection processing. This is to make it possible to make an accurate determination even when the vividness and brightness of the same color are different (exactly, the hue is different from the normally expressed hue, but will be described as the hue in the following description). ). In addition, (ma) of R, G, B of input data
Chromatic / achromatic and white are detected using the fact that the smaller the value of (x-nin), the lower the saturation, and the larger the luminance signal S110 ((R, G, B) / 3), the higher the brightness. I do.

The color detecting process in the color discriminating unit 201 of this embodiment is performed as follows.

Each of the R, G, and B data input from the shading correction circuit 102a is 8-bit data and has information of a total of 224 colors. For this reason, the scale is expensive because of its scale. In this embodiment, the following hue processing is performed using the above-mentioned hue in consideration of this point.

The input data of R, G, and B are input to the max / mid / min detecting section 120, and the max, mid, and min values and the rank signal are output, as in the conventional case. I do. Further, when each data of R, G, B is converted into two-dimensional data, in this embodiment, a common part of R, G, B, that is, min (R,
G, B) is an achromatic component, and
(R, G, B) is subtracted from each of the R, G, B data, and the remaining information is used as a chromatic component. This achieves conversion to a two-dimensional color space with a simple configuration.

For such a conversion process, the present embodiment
As in the related art, the min value, which is the minimum value, is subtracted from the max value and the mid value, and input to the hue detection unit 123 together with the rank signal. The hue detection unit 123 is a RAM or R
It is preferable that the memory device is constituted by a random access memory element such as an OM. In this embodiment, the memory device is constituted by a lookup table using a ROM.

The hue detection unit 123 is provided in advance in FIG.
A value corresponding to the angle of the plane indicated by is stored, and the input rank signal, the (max-min) value, and the (mid)
-Min), the corresponding hue value is output.
Thereby, the order of the sizes of the input R, G, and B,
Based on the maximum value and the intermediate value in R, G, and B that are input,
With a simple configuration using a lookup table, etc.,
The three-dimensional input color space is converted into a two-dimensional color space, and a corresponding hue is obtained.

The hue value output in this manner is input to the color determination circuit 217. As shown in FIG. 3, the color determination circuit 217 is composed of n window comparators. When the window comparator satisfies (an−1) <(input hue value) <(an), the AND gate n / 2 outputs “n”. 1 "is output. The outputs of the AND gates 1 to n / 2 are input to the OR gate (FIG. 3). Any A
When the ND gate outputs "1", the OR gate also outputs "1".
Is output.

The (max-min) value from the subtractor 121 is input to the comparator 210 shown in FIG. In the comparator 210, the register 104 is used by the CPU 104a.
This is compared with the reference value b1 set to 2. The comparator 210 outputs “1” when ((max−min) value) <(b1). That is, when an achromatic color is detected, "1" is output. Therefore, the AND gate 214 outputs the select signal S214 of "1" to the selector 112 of FIG. 1 when the chromatic color is a specific detection color, and the inverter 216 outputs "1" to the thin line detecting unit 203 of FIG. 1 when the chromatic color is detected. Is output. When the color determination signal S214 from the color determination circuit 217 is determined to be chromatic by the AND gate 214, the color determination signal S214 is output to the selectors 207 and 209 in FIG. When the color determination signal S214 is input to the selector 207, the pattern generation circuit 11
The pattern generated in step 4 is selected. FIG.
7, pattern generation circuit 114, address control circuit 115
It is a figure which shows the detail of.

The different patterns generated by the pattern generation circuit 114 are selected by the signal S214 by the AND gate and output through the OR gate. On the other hand, the color determination signal S214 is input to the selector 209. FIG. 5 shows a detailed configuration of the selector 209, the register 208, and the CPU 104a. Different values are set in the registers in advance by the CPU 104a, and the signal S21
4 is selected by an AND gate and output via an OR gate.

On the other hand, the comparator 211 outputs the luminance signal S 110 (= (R, G, B)) from the luminance signal generation section 110.
/ 3) is taken and compared with the reference value b2 set in the register 213. When the luminance signal S110> b2, "1" is obtained.
Is output. As a result, the subsequent AND gate 215
When the lightness of the achromatic color is higher than the set level, that is, when it is determined that the color is white, a white signal S215 of “1” is output to the fine line detection unit 203.

Next, the thin line detecting process of the thin line detecting section 203 will be described.

The thin line detecting section 203 receives the white signal S215 and the chromatic signal S216 from the color determining section 201,
Thinning circuit 22 with a different mask size around the pixel of interest
The width of the thin line is detected by 0 to 223 and the thickening circuits 224 to 227. Here, a 5 × 5 thinning circuit 221 and a thickening circuit 225 will be described.

The 5 × 5 thinning circuit 221 determines whether all the pixels in the 5 × 5 mask are the same. The input white signal S215 (“1” when the pixel is white or “0” when the pixel is not white) is input to the FIFO memory 24 of FIG.
0 to 243, 1 to 4 lines in the sub-scanning direction,
Is delayed and transmitted through XAND gates 244 to 247.
It is input to the D gate 248. The output signal of the AND gate 248 is supplied to the AND gate 261 after being delayed for each pixel in the main scanning direction by the flip-flops 249 to 252. The signals delayed by two lines in the sub-scanning direction by the FIFO memories 240 and 241 are further delayed for each pixel in the main scanning direction by flip-flops 253 to 256, and the AND gate 262 is transmitted through the XOR gates 257 to 260. Is input to

Therefore, the output signal of the AND gate 263 outputs "1" when all the signals in the 5 × 5 mask are the same, and the boundary between white and a portion other than white is output in the 5 × 5 mask. In some cases, "0" is output.

AND gate 2 in narrowing circuit 221
The output from 63 is delayed by one to four lines in the sub-scanning direction by FIFO memories 270 to 273 of the fattening circuit 225 and input to the OR gate 274. The output of the OR gate 274 is connected to the flip-flops 275 to 278.
, And is input to the NOR gate 279 for each pixel in the main scanning direction. That is, the NOR gate 279
Outputs “0” when at least one “1” exists in the 5 × 5 mask. Here, when the output signal from the NOR gate 279 is “0”, it is determined that the first input pixel data is an area having a width of 5 pixels or more. Also, N
When the output from the OR gate 279 is “1”, it is determined that the area of the image data is an area smaller than the width of 5 pixels.

In FIG. 6, for example, the 3 × 3 fattening circuit 224 outputs “1”, and the chromatic signal S 216 outputs “1”.
In this case, the AND gate 231 outputs “1”. Thus, it is determined that the area of the input image is a chromatic color area smaller than the width of three pixels. Also, a 3 × 3 fattening circuit 2
When 24 outputs “0” and the 5 × 5 fattening circuit 225 outputs “1”, the XOR gate 228 outputs “1”. At this time, it is determined that the area of the input pixel is an area having a width of 3 pixels or more and smaller than 5 pixels. Further, the XOR gate 228 outputs “1” and the chromatic signal S
216 outputs “1” and the AND gate 23
2 outputs "1".

Similarly, the outputs of the fattening circuits 225 to 227 are supplied to XOR gates 229 and 230. Further, AND gates 233 and 234 and chromatic signal S2
16, the line width of the input pixel is determined, and the determination result is shown in FIG.

As described above, the fine line detection processing is performed by the fine line detection section 203, and the output is supplied to the pattern density selection section 205 and the fixed density selection section 204 shown in FIG. 1 as a coefficient selection signal S203. On the other hand, the fixed density value of, for example, 8 bits for each color set in the register 208 by the CPU 104a is supplied to the fixed density selection unit 204, and the graphic pattern signal S203 output from the selector 112 is supplied to the pattern density selection unit 205. .

The density selection processing in the pattern density selection unit 205 and the fixed density selection unit 204 is performed as follows.

The coefficient selection signal S2 from the fine line detection unit 203
03 is supplied to the selectors 281 and 291 in FIG. 9 and selects the value set in the coefficient registers 280 and 290 by the CPU 104a. The set values are shown in FIG. The output of the selector 291 is supplied to the multiplier 292, and the graphic pattern signal S1 from the selector 112 of FIG.
Multiplied by 12. Similarly, the output of the selector 281 is supplied to the multiplier 282, and the selector 209 shown in FIG.
Is multiplied by the fixed density signal S208 of the output. further,
The outputs of the multipliers 282 and 292 are added in the adder 206 and output to the printer 103.

As described above, in this embodiment, when the line width is small, the output is performed at a fixed density set for each color according to the line width of the color area, and the ratio of the fixed density increases as the line width increases. Since the density ratio is reduced and the density ratio of the pattern is increased, thin lines are output with a high fixed density ratio set for each color, so that they can be easily identified.

FIG. 12 is a block diagram of a main part of a digital copying machine showing a second embodiment of the image processing apparatus according to the present invention. Elements common to FIG. 1 are denoted by the same reference numerals. .

This embodiment is different from the first embodiment in that a contour extracting unit (position detecting means) 300 is provided in place of the fine line detecting unit 203.

As shown in FIG. 13, the contour extracting unit 300 includes a contour extracting circuit 310-314, an XOR gate 315
318 and AND gates 319 to 322, and detects the number of input pixels from the contour in the color area. The 5 × 5 contour extraction circuit 312 will be described.

The 5 × 5 contour extraction circuit 312 has the same configuration as the 5 × 5 thinning circuit 221 shown in FIG.
Judge whether all the pixels in the mask are the same,
When all pixel signals in the mask are the same, "0" is output. Therefore, when an outline is detected in the mask, "1" is output.

Since the 1 × 1 contour extraction circuit 314 always outputs “0”, the XOR gate 318 outputs “1” when the 3 × 3 contour extraction circuit 313 outputs “1”.
Further, when the chromatic signal S216 is "1",
D gate 322 outputs "1". At this time, the input pixel is determined to be the first pixel from the outline in the color area. Similarly, when the 3 × 3 contour extraction circuit 313 outputs “0” and the 5 × 5 contour extraction circuit 312 outputs “1”, the XOR gate 317 outputs “1”.
Further, when the chromatic signal is outputting “1”, A
The ND gate 321 outputs “1”. At this time, the input pixel is determined to be the second pixel from the outline in the color area. The outputs of the contour extraction circuits 310 to 312 are:
Input to XOR gates 315-317. Next, XO
The outputs of the R gates 315 to 316 and the chromatic signal are AND
Input to gates 319 and 320. Here, the determination result is shown in FIG.

These output signals are supplied to the pattern density selector 2.
05 and the fixed density selection unit 204. According to the determination result shown in FIG. 14, the ratio of mixing the fixed density and the pattern density is changed, and the mixing ratio is
The closer to the contour, the higher the fixed density ratio is, as shown in FIG.

As described above, according to the present embodiment, the contour portion is output at a fixed density set for each color in accordance with the contour position of the color region, and the ratio of the fixed density increases as the contour portion moves inward from the contour portion. Since the density is reduced and the density ratio of the pattern is increased, the thin line is output at a high fixed density ratio set for each color, so that it can be easily identified.

[0069]

As described above, according to the first aspect, for example, when the line width is small, the output is performed at a fixed density set for each color, and the ratio of the fixed density increases as the line width increases. The density ratio of the pattern can be increased by making it smaller, and the thin line is output with a higher fixed density ratio. As a result, even a thin line such as a line graph that is color-coded can easily identify a color by a pattern, and a clear recorded image can be obtained.

According to the second aspect of the present invention, the fixed density ratio can be increased closer to the contour, and the density ratio of the pattern can be increased closer to the inside from the contour portion. Thereby, the same effect as that of the first invention is obtained. According to the third aspect, in the input color image
Is converted to a pattern image corresponding to the color,
Generates a border image at the outline of the color in the image, and
The ratio of the image and the border image according to the distance from the color outline
So that the converted pattern image is bordered
The size of the color area can be
At least the contours are not
It is possible to output in a separate state.

[Brief description of the drawings]

FIG. 1 is a block diagram of a main part configuration showing a first embodiment of an image processing apparatus according to the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of a color determining unit according to the first embodiment.

FIG. 3 is a circuit diagram of a color determination circuit in FIG. 2;

FIG. 4 is a circuit diagram of a pattern generation circuit, an address control circuit, and the like in the first embodiment.

FIG. 5 is a circuit diagram of a selector 209, a register 208, and the like in the first embodiment.

FIG. 6 is a block diagram illustrating a schematic configuration of a thin line detection unit according to the first embodiment.

FIG. 7 is a block diagram showing a schematic configuration of a narrowing circuit in the first embodiment.

FIG. 8 is a block diagram showing a schematic configuration of a fattening circuit in the first embodiment.

FIG. 9 is a block diagram showing a schematic configuration of a fixed density selection unit and a pattern density selection unit in the first embodiment.

FIG. 10 is a diagram illustrating a line width determination result of a thin line detection unit in the first embodiment.

FIG. 11 is a diagram showing set values of a coefficient register in the fixed density selecting section and the pattern density selecting section in the first embodiment.

FIG. 12 is a block diagram showing a main part of an image processing apparatus according to a second embodiment of the present invention.

FIG. 13 is a diagram showing a schematic configuration of a contour extraction unit in the second embodiment.

FIG. 14 is a diagram showing a result of position determination by a position detector in the second embodiment.

FIG. 15 is a diagram showing a combination ratio of a fixed density and a pattern density in the second embodiment.

FIG. 16 is a diagram illustrating an overall configuration of a digital copying machine that is a conventional image processing apparatus.

FIG. 17 is a block diagram illustrating a configuration of a data processing unit in the conventional image processing apparatus.

FIG. 18 is a block diagram illustrating a configuration of a color determination unit in the conventional image processing apparatus.

FIG. 19 is a block diagram showing a configuration of a pattern generator and an address controller in the conventional image processing apparatus.

FIG. 20 is an explanatory diagram of an operation of a color determination unit in the conventional image processing apparatus.

FIG. 21 is a diagram showing pattern dot data of a pattern generating unit in the conventional image processing apparatus.

FIG. 22 is a timing chart showing main signals of an address control unit in the conventional image processing apparatus.

[Explanation of symbols]

 Reference Signs List 110 luminance signal generation unit 114 pattern generation circuit 201 color determination unit 203 fine line detection unit 204 fixed density selection unit 205 pattern density selection unit 206 adder 208 register 300 contour extraction unit

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Claims (5)

(57) [Claims] 1. A color discriminating means for discriminating a color of an input image, a line width detecting means for discriminating the area width of the color, and a color discriminating means for each color according to a discrimination result by the color discriminating means.
A first signal generating means for generating a first signal of a fixed density, and a color signal which is determined for each color in accordance with a result of the determination by the color determining means.
A second signal generating means for generating a second signal representing the patterned image, and synthesizing the first signal and the second signal by changing a density ratio according to a detection result by the line width detecting means. Synthesizing means , wherein the synthesizing means has a width detected by the line width detecting means.
Is smaller, the density ratio of the first signal is higher,
The signal is synthesized by lowering the density ratio of the signal 2 and the detected width is
The thicker, the lower the density ratio of the first signal,
An image processing apparatus for synthesizing the signals while increasing the density ratio of the signals . 2. A color discrimination means for discriminating the color of the input image, a position detecting means for determining the position of the contour in the region of the color, are determined for each color according to the determination result of the color determination means
A first signal generating means for generating a first signal of a fixed density, which is determined for each color in accordance with a result of the discrimination by the color discriminating means.
A second signal generating means for generating a second signal representing the obtained pattern image, and a density ratio between the first signal and the second signal according to a detection result by the position detecting means from the contour. includes a case <br/> formed synthesizing means, said combining means, detected by said position detecting means wheel
As the position from the ku is closer, the density ratio of the first signal
High, the signal is synthesized by lowering the density ratio of the second signal, and the
As the position from the contour is farther away, the first signal
By lowering the density ratio and increasing the density ratio of the second signal
An image processing device characterized by combining . 3. A conversion means for detecting a color area in an input color image and converting the color area into a pattern image corresponding to a color, detecting an outline of a color in the input color image, and detecting the outline portion. Generating means for generating a border image in the image, and combining means for combining the pattern image from the converting means and the border image from the generating means at a ratio according to a distance from a color contour. Processing equipment. 4. The image processing apparatus according to claim 3, wherein said synthesizing means synthesizes so that the density of the border image increases as the distance from the contour increases, and decreases as the distance from the contour decreases. . 5. The image processing apparatus according to claim 4, wherein the synthesizing unit synthesizes the pattern image such that the density of the pattern image decreases as the distance from the contour decreases, and the density of the pattern image increases as the distance from the contour increases. .