JPH08317204A - Color image processor - Google Patents

Abstract

PURPOSE: To provide a color image processor which can transfer the polychromatic image signals to an image processing circuit in a small number of wirings and also can decrease the number of pins of the image processing circuit. CONSTITUTION: The analog R, G and B image signals received from an image input part 1 undergo the amplification, A/D conversion, shading correction, etc., at an RGB image output part 2. Then the B and R signals, for example, are thinned every other pixel and alternately transferred via a single line. The G signals are not thinned and transferred as they are via a single line. The B and R signals which are transferred via two lines are fetched by an interpolation arithmetic part 3a of an image processing part 3, and the thinned pixels are interpolated and outputted to the next stage. At the same time, the G signals are outputted to the next stage via a shift register 3b and synchronously with the B and R signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image processing apparatus for transferring a multicolor image signal such as a color image signal separated into three colors to perform image processing, and for example, a color copying machine, a scanner or a printer. The present invention relates to a color image processing apparatus suitable for.

[0002]

2. Description of the Related Art Conventionally, in a color image processing apparatus of this type, R, G, and B image signals separated into three colors are transferred to image processing circuits via respective data lines, and various image processing is performed by the image processing circuits. Is configured to perform processing.

Further, as a color image processing apparatus of this type, as shown in, for example, Japanese Patent Laid-Open No. 1-297247, image signals for each color are divided into colors and alternately stored in a double line buffer memory. A method of alternately reading and sending to a printer has been proposed. In this method, 3 × 2 line buffer memories are used as double line buffer memories when processing R, G, and B image signals separated into three colors.

Further, as a monochromatic image processing apparatus, for example, as shown in Japanese Patent Laid-Open No. 4-255168, a method of parallelizing serial image data by a plurality of shift registers and storing it in RAM to perform image neighborhood processing. Is proposed.

[0005]

However, in the above-described conventional color image processing apparatus, since the R, G, and B color signals are transferred to the image processing circuit via the respective data lines, data for three colors are transferred. A line is needed, and therefore
There is a problem that the amount of wiring and the number of pins of the LSI component that constitutes the image processing circuit are large.

In view of the above-mentioned conventional problems, the present invention can transfer a multicolor color image signal to the image processing circuit with a small wiring amount, and can reduce the number of pins of the image processing circuit. An object of the present invention is to provide a color image processing device that can be used.

[0007]

In order to achieve the above object, the first means thins out each pixel of the first and second color image signals pixel by pixel, and the remaining pixels are alternated into one pixel. An image output unit for outputting via a data line and each pixel input from the image output unit are separated for each of the first and second color image signals, and thinned pixels are interpolated according to adjacent pixels of the color image signal. And an interpolating means for performing the same.

According to a second means, in the first means, the image output means thins out pixel values of a third color image signal forming a color image signal together with the first and second color image signals. It is characterized by transferring without.

In a third means, the image output means in the second means modulates each pixel value of the third color image signal based on each pixel of the first and second color image signals. It is characterized by compensating for the luminance component and transferring without thinning out.

A fourth means is characterized in that in the second or third means, the first to third color image signals are RGB signals and the third color image signal is a G signal. .

A fifth means is characterized in that, in the second means, the first to third color image signals are luminance color difference system signals and the third color image signals are luminance system signals. .

A sixth means uses three lines of the third color image signal and the three lines of the first and second color image signals interpolated by the interpolating means in the second to fifth means. Filter processing means for performing filter processing,
A first line memory for storing the first and second color image signals transferred from the image output means and outputting them to the interpolation means, and a third color image signal are stored and output by the interpolation means. It further comprises a second line memory for outputting to the filter processing means in synchronization with the first and second color image signals.

The seventh means is the first and second color image signals of the current line transferred from the image output means in the sixth means or the first line of the previous line stored in the first line memory. It is characterized by further comprising switching means for selectively transferring the first and second color image signals to the first line memory.

[0014]

In the first means, the pixels of the first and second color image signals are thinned out pixel by pixel, and the remaining pixels are alternately set to 1
Data is transferred via one data line, and each pixel is transferred to the first and second
Of each color image signal and the thinned pixel is interpolated according to the adjacent pixel of the color image signal.
It is possible to transfer multicolor color image signals such as B signals and luminance color difference system signals to the image processing circuit with a small amount of wiring, and it is possible to reduce the number of pins of the image processing circuit.

The second means forms a color image signal together with the first and second color image signals.
It is possible to transfer multicolor color image signals such as B signals and luminance color difference system signals to the image processing circuit with a small amount of wiring, and it is possible to reduce the number of pins of the image processing circuit.

In the third means, each pixel value of the third color image signal is modulated based on each pixel of the first and second color image signals to compensate the luminance component and transfer without thinning. Therefore, it is possible to compensate for the reduced luminance component by thinning out each pixel of the first and second color image signals.

In the fourth means, the first to third color image signals are RGB signals and the third color image signal is a G signal, so that the RGB signals can be provided with a small wiring amount for the image processing circuit. The number of pins in the image processing circuit can be reduced.

In the fifth means, since the first to third color image signals are luminance color difference system signals and the third color image signal is luminance system signals, the luminance color difference system signals are sent to the image processing circuit. Therefore, the amount of wiring can be reduced and the number of pins of the image processing circuit can be reduced. Further, it is possible to prevent the luminance component from decreasing.

The sixth means stores the first and second color image signals transferred from the image output means and outputs the first and second color image signals to the interpolation means, and the third color image signal. Further, since the second line memory for outputting to the filter processing means in synchronization with the output signal of the interpolation means is further provided, the number of line memories can be reduced as compared with the case where the line memories for three colors are provided.

In a seventh means, the first and second color image signals of the current line or the first and second color image signals of the previous line stored in the first line memory are selectively changed to the first color image signal. Since the switching means for transferring to one line memory is further provided, the number of line memories can be reduced as compared with the case where the line memories for three colors are provided.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a block diagram showing a scanner as an embodiment of a color image processing apparatus according to the present invention, FIG. 2 is a block diagram showing a main part of the image processing block of FIG. 1, and FIG. 3 is a thinned G signal and thinned transfer. 4 is a timing chart showing the B signal and the R signal, and FIG. 4 is an explanatory diagram showing the process of interpolating the thinned pixels.

In FIG. 1, analog R, G and B image signals read by an image input unit 1 such as a color CCD are amplified by an RGB image output unit 2 and A / D converted,
After processing such as shading correction, as shown in FIGS. 3 and 4A, for example, the B signal and the R signal are thinned out for each pixel, and the B pixel and the R pixel are alternately arranged through one line. Transferred. Further, the G signal is directly transferred through one line without being thinned out.

The B & R signal thus transferred via two lines and the interpolation calculation unit 3a of the image processing unit 3 as shown in detail in FIG. The G signal is output to the subsequent stage in synchronization with the B signal and the R signal via the shift register 3b. The B & R signal and the G signal on the data line are transferred in such a manner that the leading pixel is synchronized with the main scanning synchronization signal LineSync and each pixel is synchronized with the pixel clock, as shown in FIG.

Then, the B & R transferred in this way
The signal is separated into B and R signals by the interpolation calculation unit 3a,
As shown in FIG. 4, in the block of 3 pixels × 3 lines, the coefficient α1 is assigned to each value of the six adjacent pixels B1 and B3 on the diagonal and left and right sides that are not thinned out with respect to the pixel B2 which is thinned out at the center.
Interpolation is performed by multiplying by ˜α6 and by multiplying by the number of pixels “6”. Therefore, according to the above-described embodiment, the B signal and the R signal are thinned out for each pixel and the B pixel and the R pixel are alternately transferred through one line. The amount of wiring can be used for transfer, and the number of pins of the image processing unit 3 can be reduced.

In the above embodiment, since the B signal and the R signal are thinned out for each pixel, the luminance component cannot be compensated. Therefore, when the RGB component is transferred by the RGB image output unit 2, the compensation component α of the luminance component corresponding to each value of the B signal and the R signal is compensated for by the coefficient table 2a in order to compensate the luminance component as shown in FIG. Read out from the G'signal and added to the value of the G signal by the adder 2b to compensate the luminance component for the G'signal (= G +
α) may be transferred.

Further, when the B & R signal and the G signal are delayed and transferred from the RGB image output unit 2 to the image processing unit 3, as shown in FIG. 6, delay memories 4a and 4b for two colors are provided.
Need only be provided. Further, when the image processing unit 3 performs mask processing on a block of, for example, 3 pixels × 3 lines, as shown in FIG. 7, two systems of line memories of G signal and B & R signal (5a-1, 5a-2). , (5b-1, 5
Only b-2) need be provided. Furthermore, the previous line L _-2 stored in this line memory (5b-1, 5b-2),
When the B & R signal of L ₋₁ or the current line L ₀ is further stored in the line memories (5b-1, 5b-2), the line memories (5b-1, 5b-
The multiplexers 6a and 6b may be provided before the step 2).

Here, in the above embodiment, the RGB signal is transferred as the color image signal,
Instead, as shown in FIG. 9, R, G, and
The B signal is converted into the luminance color difference system signals L ^* , a ^* , b ^* by the L ^* a ^* b ^* image output unit 20, and the luminance signal L ^* remains as it is, and the color difference signals a ^* , b ^* are pixel by pixel. You may make it thin and transfer for every pixel via one line.

In this case, the color difference signals a ^* and b ^* thus transferred via the two lines are fetched by the interpolation calculation section 31 of the image processing section 30, and the thinned pixels are interpolated to the subsequent stage. Further, the luminance signal L ^* is output to the subsequent stage through the shift register 32 in synchronization with the color difference signals a ^* and b ^* signals. In this embodiment, the luminance signal L ^*
Is transmitted as it is, so that the luminance component compensation circuit as shown in FIG. 2 is unnecessary.

[0029]

As described above, according to the first aspect of the invention, each pixel of the first and second color image signals is thinned out pixel by pixel, and the remaining pixels are alternately arranged via one data line. Are transferred, the pixels are separated for each of the first and second color image signals, and the thinned pixels are interpolated according to the adjacent pixels of the color image signal. Therefore, for example, an RGB signal or a luminance color difference system signal. A multicolor image signal can be transferred to the image processing circuit with a small amount of wiring, and the number of pins of the image processing circuit can be reduced.

According to the second aspect of the present invention, since the color image signal is formed together with the first and second color image signals, the multi-color image signals such as RGB signals and luminance color difference system signals are processed by the image processing circuit. Therefore, the amount of wiring can be reduced and the number of pins of the image processing circuit can be reduced.

According to the third aspect of the present invention, the luminance component is compensated by modulating each pixel value of the third color image signal based on each pixel of the first and second color image signals, without thinning out. Since they are transferred, it is possible to compensate for the luminance component that decreases by thinning out each pixel of the first and second color image signals.

According to a fourth aspect of the present invention, since the first to third color image signals are RGB signals and the third color image signal is a G signal, the RGB signals are less wired to the image processing circuit. The number of pins of the image processing circuit can be reduced.

According to a fifth aspect of the present invention, the first to third color image signals are luminance color difference system signals and the third color image signal is a luminance system signal. Therefore, the luminance color difference system signals are transmitted to the image processing circuit. Therefore, the amount of wiring can be reduced and the number of pins of the image processing circuit can be reduced. Further, it is possible to prevent the luminance component from decreasing.

According to a sixth aspect of the invention, there is provided a first line memory for storing the first and second color image signals transferred from the image output means and outputting them to the interpolation means, and a third color image signal. And a second line memory for storing the data and outputting it to the filter processing means in synchronization with the output signal of the interpolation means. Therefore, the number of line memories can be reduced as compared with the case where the line memories for three colors are provided. .

The invention according to claim 7 is the first of the present line,
Since it further has a switching means for selectively transferring the second color image signal or the first and second color image signals of the previous line stored in the first line memory to the first line memory, 3 The number of line memories can be reduced as compared with the case where the color line memories are provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing a scanner as an example of a color image processing apparatus according to the present invention.

FIG. 2 is a block diagram showing a main part of an image processing block in FIG.

FIG. 3 is a timing chart showing non-thinned G signals, thinned-out B signals and R signals.

FIG. 4 is an explanatory diagram showing a process of interpolating a thinned pixel.

FIG. 5 is a block diagram showing a modified example of the RGB image output unit of FIG.

FIG. 6 is a block diagram showing a color image processing apparatus of a second embodiment.

FIG. 7 is a block diagram showing a color image processing apparatus of a third embodiment.

FIG. 8 is a block diagram showing a modification of the color image processing apparatus of the third embodiment.

FIG. 9 is a block diagram showing a color image processing apparatus of a fourth embodiment.

[Explanation of symbols]

2 RGB image output unit 2a coefficient table 2b adder 3,30 image processing unit 3a, 31 interpolation calculation unit 3b, 32 shift register 4a, 4b delay memory 5a-1, 5a-2, 5b-1, 5b-2 line memory 6a, 6b multiplexer 20 L ^* a ^* b ^* image output unit

Claims (7)

[Claims] 1. An image output unit for thinning out each pixel of the first and second color image signals pixel by pixel and alternately outputting the remaining pixels through one data line, and the image output unit. The input pixels are converted into the first and second
A color image processing device including: an interpolating unit that separates each color image signal and interpolates a thinned pixel according to an adjacent pixel of the color image signal. 2. The image output means transfers the respective pixels of a third color image signal forming a color image signal together with the first and second color image signals without thinning out the pixels. 1. The color image processing device according to 1. 3. The image output means compensates a luminance component by modulating each pixel value of a third color image signal based on each pixel of the first and second color image signals, without thinning out. The color image processing apparatus according to claim 2, wherein the color image processing apparatus transfers. 4. The color image processing apparatus according to claim 2, wherein the first to third color image signals are RGB signals and the third color image signal is a G signal. 5. The color image processing apparatus according to claim 2, wherein the first to third color image signals are luminance color difference system signals and the third color image signals are luminance system signals. . 6. A filter processing means for performing a filter processing using each of the three lines of the third color image signal and the first and second color image signals interpolated by the interpolation means, and the image output. A first line memory for storing the first and second color image signals transferred from the means and outputting them to the interpolating means; and a first line memory for storing a third color image signal and outputting by the interpolating means. 6. The color image processing apparatus according to claim 2, further comprising a second line memory that outputs the second color image signal to the filter processing unit in synchronization with the second color image signal. 7. The first and second color image signals of the current line transferred from the image output means or the first and second color image signals of the previous line stored in the first line memory 7. The color image processing apparatus according to claim 6, further comprising switching means for selectively transferring to the first line memory.