JPH08340454A - Color image processor - Google Patents

Abstract

PURPOSE: To obtain a color image processor which can facilitate and speed up color image processing by a central processing unit and also lower the cost by saving a frame memory. CONSTITUTION: Pixel data are inputted as RGB signals to a color specification system analog converting means 4a. The color specification system converting means 4a1 of the color specification system analog converting means 4a performs conversion into color specification through analog signal processing according to a color specification control signal 5 from the central processing unit 1. Then color information that the central processing unit 1 requires is calculated and selected, and outputted to an A/D conversion part 3. The A/D conversion part 3 converts it into a digital signal of proper gradations and outputs it to the frame memory 2. The central processing unit 1 performs a process such as color recognition by using data of a color specification system in the frame memory.

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 image-processing a video signal containing color information, and more particularly to a color image processing apparatus capable of high-speed and low-cost color recognition processing.

[0002]

2. Description of the Related Art Conventionally, a system shown in FIG. 10 has been used to perform image processing such as skin color recognition. This method first separates a color image into the three primary colors of RGB, and
The / D converter 3 converts the analog signal into a digital signal, and stores the digital signal of the RGB image in the frame memory 2 corresponding to the three primary colors of RGB. In the central processing unit 1 that is responsible for image processing, coordinate conversion calculation is performed from an RGB image to another color system, and then threshold processing is performed to recognize the target color.

The color coordinate conversion is, for example, conversion from RGB system to CIE1931XYZ system based on the following formula.

[Equation 1] Next, the CIELAB system is converted based on the following equation.

[Equation 2] After that, calculation such as conversion to the Munsell HVC color system is performed. By this processing, the brightness V, the hue H, and the saturation C are obtained, and for example, image data in a certain hue range can be recognized as a skin color.

[0004]

However, it takes a long time to perform such a calculation in the central processing unit for each one pixel of the input image, and the real-time property of recognition is significantly impaired. Further, three kinds of frame memories corresponding to RGB signals are always required, which is one of the causes of cost increase. As shown in FIG. 11, there is a method of increasing the speed by processing this arithmetic processing by a dedicated color system conversion processor 6, but a table for storing color converted data in addition to a frame memory corresponding to RGB signals. The color system converted memory 7 is required, and the processor and the memory are too expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a color image processing apparatus capable of performing color image processing of a central processing unit easily and at high speed, saving frame memory and realizing low cost.

[0006]

According to a first aspect of the present invention, a central processing unit and an input analog RGB signal are converted into an appropriate color system by a color system control signal from the central processing unit. A colorimetric system analog conversion means for converting the colorimetric parameters to a colorimetric parameter and outputting the colorimetric parameter, and an A / D conversion part for quantizing the colorimetric parameter converted by the colorimetric system analog conversion means. A color image processing apparatus comprising: a frame memory that stores the color specification parameters quantized by an A / D conversion unit.

According to a second aspect of the present invention, there is provided a central processing unit,
Three A / s to quantize the input analog RGB signal
The D conversion unit and the RGB signal quantized by the A / D conversion unit are digitally converted into an appropriate color system by the color system control signal from the central processing unit, and the color parameter is selected from them. A color image processing device comprising: a colorimetric system digital conversion means for selecting and outputting; and a frame memory for storing the colorimetric parameters converted by the colorimetric system digital conversion means.

According to a third aspect of the present invention, there is provided a central processing unit,
An NTSC color system conversion means for converting an input NTSC signal into an appropriate color system by a color system control signal from the central processing unit, selecting a color parameter from the color system and outputting it, and the NTSC table. An A / D conversion unit for quantizing the color specification parameter converted by the color system conversion unit;
A color image processing device, comprising: a frame memory that stores the color specification parameters quantized by the / D conversion unit.

According to a fourth aspect of the present invention, there is provided the color image processing apparatus according to the first, second or third aspect in which the frame memories are provided only in types corresponding to the color specification parameters to be stored.

[0010]

In general, in color recognition, the luminance information is not used and the saturation information is not used. This means that the color recognition device can use a small amount of frame memory. However, a device that can sample only specific color information lacks flexibility. Therefore, in the present invention, a means for converting the color system is provided before or immediately after the A / D conversion unit, which is a means for A / D converting an image, and a conventional frame memory for storing an image to be processed is provided. Instead of being stored in the RGB color system, data in the color system that allows easy color recognition in the central processing unit is stored. Further, the color system conversion means can be controlled by the central processing so as to correspond to various color systems, and the central processing unit can specify what of the obtained color information is sent to the frame memory. To

By constructing such a system, since the color information converted into an appropriate color system is stored in the frame memory as it is, the central processing unit can perform simple threshold value processing and the like. The color image can be recognized by the processing, and the processing speed can be increased.

Further, in the conventional technique, a memory is required for each RGB frame, so that the frame memory is 3
In the present invention, only the color information required for recognition by the central processing unit, for example, in the case of recognizing the hue, only the frame memory for storing the hue needs to be prepared. Therefore, the frame memory required for the color recognition program can be saved.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings.

<First Embodiment> FIG. 1 is a block diagram showing a first embodiment of a simplified color image processing apparatus according to the present invention. This simplified color image processing device is a central processing unit 1
A frame memory 2, an A / D converter 3, and a color system analog converter 4a.

As shown in FIG. 2, the color system analog converting means 4a comprises a color system converting means 4a ₁ and a selecting means 4a ₂ . The color system conversion means 4a ₁ constitutes a matrix conversion by a network of resistance elements, and performs the above-mentioned conversion by analog signal processing by the color system control signal 5. The selecting means 4a ₂ is a selector of 3 inputs and 1 output, and is composed of an analog switch or the like, and selects color information required by the central processing unit 1 by a color system control signal 5.

Image data picked up by a color video camera or the like is converted into an RGB signal as a color system analog converting means 4.
Input to a. The color system conversion means 4a ₁ of the color system analog conversion means 4a uses, for example, the formulas (1) and (2) described in the prior art according to the color system control signal 5 from the central processing unit 1. The conversion to the LAB system or the conversion to the equations (1) and (2) and Munsell HVC color specification is performed by analog signal processing. Then, the color information required by the central processing unit 1 is calculated and selected by the selection means 4a ₂ and output to the A / D converter 3. The A / D converter 3 converts it into a digital signal having an appropriate gradation (for example, 8 bits) and outputs it to the frame memory 2. In the central processing unit 1, if it is desired to obtain a hue H value in the Munsell HVC color system, the color system analog conversion means is instructed as a color system control signal 5, so that the frame memory is used. The H-converted value of the input image can be obtained from 2, and recognition or the like can be performed by extracting the portion corresponding to the H-converted value in the hue H range.

In this way, the color system conversion means 4a is placed in front of the A / D conversion section 3, the RGB signals are color-converted, and the signals are stored in the frame memory 2. Since color specification conversion processing is performed as preprocessing in this way, the color information converted into an appropriate color specification system is stored in the frame memory as it is, and the central processing unit 1 receives the signal from the frame memory 2 as a signal. When performing image processing (for example, color recognition), the processing speed is increased. In addition, it is possible to recognize the color image by a simple process such as threshold processing.

Since only one-dimensional information such as luminance or hue is sufficient for the processing in the central processing unit, the frame memory is not the three types corresponding to the RGB signals as in the conventional case, but the one shown in FIG. As shown, only one type is required. That is, the system can be constructed at low cost.

<Second Embodiment> FIG. 3 is a block diagram showing a second embodiment of the present invention, which is different from the first embodiment in the following points. Since the color system conversion means is changed from the analog system to the digital system color system digital conversion means 4b and the RGB signals must be quantized in advance, the A / D
The difference is that the number of conversion units 3 is increased to three.

This color system digital converting means 4b is shown in FIG.
As shown in FIG. 5, it is composed of color system conversion means 4b ₁ and selection means 4b ₂ . The color system conversion means 4b ₁ is composed of a digital signal processor DSP, a product-sum operation processing circuit, etc., and performs digital signal processing by the color system control signal 5.
Therefore, the degree of freedom in color system conversion is higher than in the first embodiment. The selecting means 4xd is composed of a 3-input 1-output multiplexer similar to that of the first embodiment.

Image data picked up by a color video camera or the like is converted into analog RGB signals by A /
It is input to the B conversion unit 3 and converted to digital. The signal is input to the color system digital converting means 4b. The color system conversion means 4b ₁ of the color system digital conversion means 4b performs conversion to the LAB system or Munsell HV as described above according to the color system control signal 5 from the central processing unit 1.
The conversion process to C color is performed by digital signal processing. It is then calculated and selecting the color information in need of a central processing unit 1 in the selection means 4b _2, and outputs to the frame memory 2. The central processing unit 1 performs processing such as color recognition based on the color information in the frame memory 2.

The color system conversion means 4b is placed immediately after the A / D conversion section 3 to perform color conversion processing of RGB signals and store the signals in the frame memory 2. Since the color conversion processing is performed as the preprocessing in this way, the processing speed is increased when the central processing unit 1 performs the image processing with the signal from the frame memory 2. Further, similarly to the first embodiment, the central processing unit can recognize the color image by a simple process such as threshold value processing, and the central processing unit only processes one-dimensional information. If the above is sufficient, only one type of frame memory is required, and the system can be constructed at low cost.

<Third Embodiment> FIG. 5 is a block diagram showing a third embodiment of the present invention, which is different from the first embodiment in the following points. That is, the point is that the NTSC color system conversion means 4c is used as the color system conversion means, and the NTSC color system conversion means 4c includes a Y / C separation unit 4c _{1 as} shown in FIG.
It includes a hue / saturation extraction unit 4c ₂ and a selection unit 4c ₃ . Here, the selecting means 4c ₃ is a selector with 3 inputs and 1 output and is constituted by an analog switch or the like.

Image data picked up by a color video camera or the like is input to the NTSC color system conversion means 4c as an NTSC signal. In the NTSC color system conversion means 4c, the Y / C separation unit 4c ₁ performs Y / C separation, and then the hue / saturation extraction unit 4c ₂ extracts the hue / saturation signal from the C signal. Then, the selection means 4c ₃ calculates and selects the color information to be sent to the A / D conversion section 3 in accordance with the color system control signal 5. The A / D converter 3 converts it into a digital signal having an appropriate gradation and outputs it to the frame memory 2. The central processing unit 1 performs processing such as color recognition based on the color information in the frame memory 2.

Since the central processing unit 1 can obtain the luminance, the hue or the saturation, the recognition can be performed based on appropriate information. Also in this case, as in the first embodiment,
The image processing of the central processing unit 1 can be speeded up and simplified, and the frame memory can be saved depending on the type of color recognition processing.

<Other Embodiments> The NTSC color system conversion means may perform color conversion by a method different from the above.
For example, once converted to RGB signals, then from the RGB system to X
It may be converted into a YZ system, a LAB system, a Munsell HVC color system, or the like.

Further, the frame memory is 1 as described above.
It is not limited to types. For example, the fourth, fifth, and sixth embodiments illustrated in FIGS. 7, 8, and 9 are cases in which two or more types of frame memories are included in the above-described first, second, and third embodiments. Other than the number of memories, the first,
It is basically the same as the configuration of the second and third embodiments. Further, the constitution of each color system conversion means 4ax, 4bx, 4cx is also the same as that of the color system conversion means 4a, 4b, 4c of the first, second and third embodiments shown in FIGS. 2, 4 and 6. . However,
Each selection means forming the color system conversion means 4ax, 4cx is an analog switch, and the selection means forming the color system conversion means 4bx is a multiplexer, each having three inputs and two or more outputs. ing. Two or more types of frame memories are provided for each color system conversion means 4ax, 4bx, 4
Data of two or more color specification parameters generated from cx can be stored.

As described above, in the processing such as color recognition in the central processing unit 1, when it is necessary to perform processing such as whether or not brightness, hue, saturation and the like satisfy complicated conditions,
The type of frame memory may be set according to the color specification parameters (luminance, hue, saturation, etc.) required for image processing.

[0029]

As described above, according to the present invention,
Since the colorimetric conversion means is placed before or immediately after the A / D conversion section to perform the preprocessing of the colorimetric conversion processing, the color conversion can be performed at high speed and easily. Also, the frame memory only needs to be of a type corresponding to the colorimetric parameters required for colorimetric conversion processing, and since the frame memory can be saved according to the colorimetric parameters, the system can be configured simply and at low cost. You can

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a color image processing apparatus according to the present invention.

FIG. 2 is a block diagram showing a color system analog converting means in the first embodiment.

FIG. 3 is a block diagram showing a second embodiment of the color image processing apparatus according to the present invention.

FIG. 4 is a block diagram showing a color system digital converting means in the first embodiment.

FIG. 5 is a block diagram showing a third embodiment of the color image processing apparatus according to the present invention.

FIG. 6 is a block diagram showing NTSC color system conversion means in the first embodiment.

FIG. 7 is a block diagram showing a fourth embodiment of the color image processing apparatus according to the present invention.

FIG. 8 is a block diagram showing a fifth embodiment of the color image processing apparatus according to the present invention.

FIG. 9 is a block diagram showing a sixth embodiment of the color image processing apparatus according to the present invention.

FIG. 10 is a block diagram showing an example of a conventional color image processing apparatus.

FIG. 11 is a block diagram showing another example of a conventional color image processing device.

[Explanation of symbols]

 1 Central Processing Unit 2 Frame Memory 3 A / D Converter 4a Colorimetric Analog Converter

Claims (4)

[Claims] 1. A central processing unit and an input analog RGB signal are converted into a proper color system in an analog manner by a color system control signal from the central processing unit, and a color parameter is selected therefrom. A color system analog conversion unit for selecting and outputting, an A / D conversion unit that quantizes the color specification parameters converted by the color system analog conversion unit, and the A / D conversion unit quantized by the A / D conversion unit. A color image processing apparatus comprising: a frame memory that stores color specification parameters. 2. A central processing unit and three A / s for quantizing input analog RGB signals.
The D conversion unit and the RGB signal quantized by the A / D conversion unit are digitally converted into an appropriate color system by the color system control signal from the central processing unit, and the color parameter is selected from them. A color image processing apparatus comprising: a colorimetric system digital conversion means for selecting and outputting; and a frame memory for storing the colorimetric parameters converted by the colorimetric system digital conversion means. 3. A central processing unit and an input NTSC signal are converted into an appropriate color system by a color system control signal from the central processing unit, and a color parameter is selected and output from the color system. An NTSC color system conversion unit, an A / D conversion unit that quantizes the color specification parameter converted by the NTSC color system conversion unit, and the color specification parameter quantized by the A / D conversion unit. A color image processing device comprising: a frame memory for storing the color image. 4. The color image processing apparatus according to claim 1, wherein the frame memory is provided only in types corresponding to stored color specification parameters.