JP3392910B2 - Digital color copier - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital color copying machine having a color conversion function, and more particularly to a digital color copying machine for performing color conversion close to human sensitivity.

[0002]

2. Description of the Related Art Conventionally, an "image processing apparatus" disclosed in Japanese Patent Application Laid-Open No. 2-87778 is known as a reference technical document related to the present invention. This "image processing device"
The read image data is separated into lightness data and chromaticity data, and only the chromaticity data is converted into an arbitrary single color while holding the lightness data, thereby enabling a single-color copy with an arbitrary color.

Further, the above-mentioned "image processing device" uses the one in which lightness data and chromaticity data are separated for color conversion. In the case of a single color copy, the chromaticity data is converted into the desired chromaticity data of a single color. It shows that it should be converted. This is just one method of monochrome copying. In the manual image quality adjustment and color adjustment, it shows what kind of adjustment keys have been used conventionally, and there are sharp / soft, contrast, background removal, and pastel keys. All color adjustments are performed independently by the user, mainly R (red), G (green), B (blue), C (cyan), M (magenta), Y (yellow), Bk (black). It is like this.
Sensitivity is expressed by the sharp / soft key and the contrast key. The former is adjusted by the filter coefficient and the latter is adjusted by the gamma curve.
Color selection indicates full-color output or single-color output. Designated colors R, G, B, and
C, M, Y, Or (orange), Lg (light green), Bk, W (white), original color, and registered color. For color conversion, R, G, B in the manuscript,
C, M, Y, Bk, W are designated colors R, G, B, C, M,
It has a function of converting to Y, Or, Lg, Bk, W and any one of the original color and the registered color, and it is possible to convert up to four colors at the same time.

In the conventional image processing, the gamma correction is performed on the scanner data, the color conversion is not performed as RGB, and the Y output is used for printer output.
Color correction for conversion to MCBk is performed, and gradation processing is performed to perform area gradation or the like. The conventional operation section has a contrast and
User keys such as sharp / soft, background removal, and pastel are provided.

[0005]

However, in the image processing apparatus as shown above, the color selection and the color conversion are color conversions which are mainly composed of distinct colors as described above. ， There was a problem that the operation was complicated and it took a lot of time to master it.

The present invention has been made in view of the above, and the drawbacks of the prior art in that color conversion-related operations are very complicated and difficult to understand by providing more sensitivity keys in the operation unit. The purpose is to improve operability by eliminating.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has a color tone of either cold side or warm side .
With respect to the cold / warm system adjustment input means for instructing adjustment in one direction and the read color signal, the brightness is maintained based on the input information of the cold / warm system adjustment input means, and the CIE XYZ table is displayed.
The origin of the a * b * plane of the color system, L * a * b * space is defined as a
* B * Parallel to the direction away from the cold / warm boundary on the plane
( EN) A digital color copying machine provided with image processing means for changing saturation and hue by executing movement conversion .

[0008]

Also, the hue should be on the cold side or the warm side .
A cold-warm-based adjustment input means for adjusting instruct Zureka one direction, relative to the read color signals, based on input information of the cold-warm-based adjustment input means, image processing means to restrict the hue to be developed image output And the image processing means includes the cold and warm
If cold color is selected in the system adjustment input means,
If Cone, Cyan, Blue, or Warm is selected,
Only in yellow, red, and magenta, it will be output in the manuscript.
If there is a color component other than the hue
All replaced with white, is to provide a digital color copying machine you output control hue.

[0010]

[0011]

[Action] digital color copying machine according to the present invention, heat and cold
Adjust the hue from the system adjustment input means to the cold or warm side .
Adjustment instruction in one direction or deviation , and for the read color signal,
Based on the input information of the cold / warm system adjustment input means, while maintaining the brightness, the CIE XYZ color system, L * a * b * sky
The origin of the a * b * plane between is the cold color on the a * b * plane.
A translation conversion can be performed in the direction away from the warm boundary.
And change the saturation and hue.

[0012]

Furthermore, before adjusting instructing tint to any one direction of the cold side or warm side of the cold-warm-based adjustment input means
Image processing based on input information from the cold / warm system adjustment input means
For the means, cold color was selected in the cold / warm system adjustment input means.
In this case, green, cyan, blue, warm colors are selected.
If it is, the manuscript is limited to yellow, red and magenta
If there is a color component other than the output hue in,
Replace all the color components with white and control the output of hue.
It

[0014]

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a schematic configuration of a digital color copying machine to which the present invention is applied. In the figure, 101 is a scanner as a means for optically scanning a document to read one or more kinds of color signals, and 102 is image processing for performing density correction, color correction, gradation correction, etc. on the read color signals. An image processing unit 103 is a printer, a printer 103 is a device for visualizing data obtained by the image processing unit, and a system controller 104 is a control unit for controlling these three devices as a whole.
Reference numeral 05 denotes an operation unit as an operation unit that gives user information to the control unit.

Next, the basic operation of the digital color copying machine configured as described above will be described. First, a document to be read is optically scanned to read a plurality of color signals of one or more colors with the scanner 101. The scanner 1
The color signal read by 01 is subjected to processing such as density correction, color correction, and gradation correction by the image processing unit 102. Further, the printer 103 visualizes the data obtained by the image processing unit 102. At this time, the system controller 104 controls the three means of the scanner 101, the image processing unit 102, and the printer 103 as a whole. And, in this system controller 104,
User information is given by the operation unit 105. Also,
Data is exchanged in RGB between the scanner 101 and the image processing unit 102, and in Y, M, C, and Bk between the image processing unit 102 and printer 103.

FIG. 2 is an explanatory view showing the main part of the operation unit 105 according to the present invention. In the figure, the operation unit 105 is provided with a cold / warm color key 201 as a hue adjustment key and a contrast key 202.

Further, FIG. 3 shows an image processing unit 1 according to the present invention.
2 is a block diagram showing a detailed configuration of 02. FIG. The image processing unit 102 includes a γ correction circuit 301 that executes gamma correction based on a gamma characteristic, and C
A color system conversion circuit 302 for converting to the IE XYZ color system,
A color conversion circuit 303 for performing RGB color conversion, and a color correction circuit 30 for performing color correction on YMCBK for printer output.
4, gradation correction circuit 30 for executing gradation processing such as area gradation
5 are connected in series.

The operation of the operation unit 105 and the image processing unit 102 configured as above will be described. Operation unit 10
5 has a cold / warm color key 201 as a hue adjustment key, and sends this data to the image processing unit 102 through the system controller 104. In the image processing unit 102, the color system conversion circuit 302 is inserted between the γ correction circuit 301 and the color conversion circuit 303, and the gamma-corrected RGB data is converted into CIE XYZ color system L * a * b * (L Star,
Converted to a star, b star), and converted data on the a * b * plane with the cold / warm color key 201, and again with the L * input to the color conversion circuit 303 retained, to RGB again. It is converted and sent to the color correction circuit 304.

Now, the CIE XYZ color system will be described. The values XYZ are known to be created in accordance with the luminosity characteristics of the human eye, in contrast to RGB, which is a filter formed by dividing the wavelength range that the human eye can decompose into three. L * a obtained from this XYZ value
The value of * b * indicates hue, lightness, and saturation that match human visual characteristics. In the present invention, since kansei expression is used as the conversion operation, color conversion is performed based on this L * a * b *. From this RGB to XYZ, L * a * b
The formula for converting to * is shown below.

[0021] Y = 0.177R + 0.812G + 0.011B X = 0.490R + 0.310G + 0.200B Z = 0.000R + 0.010G + 0.990B L * = 116 {(Y / Y0) (1/3 power)}-16 a * = 500 [{(X / X0) (1/3 power)} -{(Y / Y0) (1/3 power)}] b * = 200 [{(Y / Y0) (1/3 power)} -{(Z / Z0) (1/3 power)}] However, the above X0, Y0, and Z0 are values of the reference white board.

Further, L * in the above represents the lightness itself, and the hue and the saturation are represented from the two values of a * b *. The coordinates of the L ^* axis and a * b * are shown in FIG. The lightness is represented on the L ^* axis, with high data indicating bright and low data indicating dark. The hue is determined by which quadrant it is in. As shown in FIG. 4, the color on the positive side on the b * axis is yellow, and clockwise in red, magenta, blue, cyan, green, and yellow areas. Be divided. As for the saturation, the farther the distance from the origin is, the more saturated the color is. On the other hand, the closer to the origin, the closer to the achromatic color. If the cold colors are blue, cyan, and green, and the warm colors are yellow, red, and magenta, the cold / warm boundary on the a * b * plane passes through the origin and is close to a straight line with a slope of -2. Become.

In the present invention, when the cold color is selected by the cold / warm color key 201, the saturation of the cold color is increased while maintaining the lightness, and the hue of the warm color on the boundary between the cold color and the warm color is changed to the cold color side. When the warm color is selected, the saturation on the warm color side is increased while maintaining the lightness, and the hue on the cold color side at the boundary between the warm color and the cold color is converted to the warm color side.

As described above, by having human-sensitivity expression of cold color or warm color as the operation means, the operation becomes simpler than ever, and since all hues are expressed, the fidelity of the manuscript remains unchanged. You can leave. In addition to this, since a formula that can be converted from the input data RGB is used, verification is easy and hardware can be realized.

In the present invention, the cold / warm color key 201
Therefore, when a cold color is selected, only the cold side of all hues (green, cyan, blue system) is expressed by the hue, and the warm color of the original is expressed by the cold color which is the complementary color of the warm color, or nothing. It is colored or completely white. When warm color is selected, only the warm color side of all hues (yellow, red, magenta) is expressed, and the cold color of the manuscript is expressed by warm color which is the complementary color of the cold color or achromatic color. Or it becomes completely white. These will be specifically described below.

FIG. 5 is an explanatory view showing the L * a * b * space of the CIE XYZ color system according to the present invention. Operation unit 10
If the cold / warm color key 201 of 5 is set to the standard (center), color conversion is not performed, so L * a * b * output from the color system conversion 302 is saved as it is, and the warm color point of FIG. The coordinates of Cd and the cold point Ck are (L1 *, a1 *, b
1 *) (L2 *, a2 *, b2 *). Next, when the cold / warm color key 201 of the operation unit 105 is shifted to the cold side by one step or more, the origin of a * b * is set to the warm side (the effect of the present invention in any direction is Although it appears, it is better to shift to a straight line that is vertical from the cold / warm color boundary and passes through the origin in order to convert the entire cold color area evenly.) C0 (L0 *, a0 *, b0 in FIG. 5
*) From this, the warm color point Cd is (L1 *, a1 *
-A0 *, b1 * -b0 *), the cold point Ck is (L2 *,
a2 * -a0 *, b2 * -b0 *). a1 *, b
Since 1 * is plus and a2 * and b2 * are minus,
The warm color point Cd is closer to the origin, and the cold color point Ck is farther from the origin. That is, the warm color point has a low saturation, and the cold color point has a high saturation and a distinct color, resulting in a feeling that the entire image is drawn. On the contrary, when shifted to the warm color side, the origin is closer to the cold color side, the distance between the cold color point Ck and the origin is closer, the warm color point Cd is far from the origin, and the cold color point is low in saturation. At the warm color point, a deep and saturated color is obtained.

Therefore, according to the above, by providing the cold / warm color key 201 indicating the sensitivity, the man-machine interface can be improved, and the near full-color representation makes it possible to produce a faithful and user-friendly representation of the original. It will be possible.

FIG. 6 shows the CIE XY according to the present invention.
It is explanatory drawing which shows the L * a * b * space of Z color system. By expressing only the cold color or the warm color as the color,
The present invention intends to more effectively express coldness and warmth. Here, the cold / warm color key 201 of the operation unit 105 is used in the same manner as above. When the cold color side is selected by the cold / warm color key 201, only blue, cyan, and green colors are used as output colors, so that Cd in the warm color needs color conversion. In this example, all the colors on the warm side are complementary colors, so only the hue is rotated while maintaining the saturation. That is,
The data should be point-symmetrical around the origin.
The complementary color of the warm color Cd is moved to the point Cd1 of (L1 *, -a1 *, -b1 *). The same applies when the warm color side is selected, and this time it is sufficient to make the color on the cold color side point-symmetrical about the origin.

Further, the hues to be output are limited to green, cyan, and blue when the cold color is selected, and yellow, red, and magenta when the warm color is selected. If a color component other than is present, all the color components are achromatic. This is because all the colors on the warm color side are converted into achromatic colors, so the data of the warm color Cd is moved to the point Cd2 of (L1 *, 0,0) while maintaining the lightness. The same is true when the warm color side is selected. This time, the achromatic color conversion on the cold color side is executed by setting the value of a * b * of the color on the cold color side to 0.

The hues to be output are limited to green, cyan, and blue when the cold color is selected, and yellow, red, and magenta when the warm color is selected. If there is a color component other than, replace that color component with white. Since all the colors on the warm color side are set to 0, the data of the warm color Cd is moved to the point Cd3 of (0, 0, 0). The same applies when the warm color side is selected, this time the L color of the cold side
All of * a * b * are 0.

As described above, by having human being's sensual expression as cold or warm color as the operation means, the operation becomes easier than ever, and by expressing only cold color or warm color. ， Can create more original images. Therefore, according to the above, by providing the key indicating the sensitivity, the man-machine interface can be improved and the output color can be limited to the cold color and the warm color to make more original expression. .

[0032]

As described above, according to the digital color copying machine of the present invention, a key is provided which indicates the sensitivity of the user to the cold color side or the warm color side, and based on the designation information from the key, Since the color characteristics of lightness, saturation, and hue are controlled, the operations related to color conversion are simplified and the operability is significantly improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a digital color copying machine to which the present invention is applied.

FIG. 2 is an explanatory diagram showing a configuration of an operation unit according to the present invention.

FIG. 3 is a block diagram showing a detailed configuration of an image processing unit according to the present invention.

FIG. 4 is an L * a * of a CIE XYZ color system according to the present invention.
It is a * b * top view of b * space.

FIG. 5 is an L * a * of the CIE XYZ color system according to the present invention.
It is a * b * top view of b * space.

FIG. 6 is an L * a * of a CIE XYZ color system according to the present invention.
It is a * b * top view of b * space.

[Explanation of symbols]

102 image processing unit 105 Operation part 201 warm / cold key 301 γ correction circuit 302 Color system conversion circuit 303 color conversion circuit 304 color correction circuit 305 gradation correction circuit

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Claims (2)

(57) [Claims] 1. The hue is either cold or warm.
Or 1 and the cold-warm system adjustment input means for adjustment instruction to the direction, with respect to read color signals, based on input information of the cold-warm-based adjustment input means, while the brightness was maintained, CIE of the XYZ color
The origin of the a * b * plane of the system L * a * b * space is the a *
b * Parallel shift in the direction away from the cold / warm boundary on the plane
A digital color copying machine comprising: an image processing unit that changes saturation and hue by executing dynamic conversion . 2. The hue is either cold or warm.
The image forming apparatus includes a cold / warm system adjustment input means for instructing adjustment in one direction , and an image processing means for limiting a hue to be output as a visible image based on input information of the cold / warm system adjusting means with respect to the read color signal. and, said image processing means, in the cold-warm-based adjustment input means
Green, cyan, blue if cold colors are selected
System, yellow, red, maze when warm color is selected
Only the input system, the original contains color components other than the output hue.
If present, replaces all its color components with white
A digital color copying machine characterized by controlling the output of hue .