JPH0683947A - Image processing device - Google Patents

Abstract

PURPOSE:To require only one computing element, and reduce the manufacture cost and reduce the size of the device by selectively performing arithmetic for RGB-to-Y color difference conversion or Y color difference-to-RGB conversion by the computing element. CONSTITUTION:An analog video signal which is inputted from a terminal 1 is converted by an A/D converter 2 into digital data, which are temporarily stored in an area of one of memories 1-(n) of an image memory 3. Then parameters of the computing element 4 are set by a CPU 6 for RGB-to-Y color difference conversion and the image data stored in the memory area are converted through the computing element 4 and stored in another image memory area. Consequently, the RGB-to-Y color difference conversion can be performed in one frame time and the parameters of the computing element 4 are re-set by the CPU 6 for the reconversion; and then an image converted to a Y color difference is reconverted into an RGB image, which is outputted through a D/A converter 5, thereby advancing processes for editing, composition, conversion, cutting, etc., while the image is referred to on a display.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital image processing apparatus, and more particularly to an image processing apparatus for capturing and processing a still image.

[0002]

2. Description of the Related Art A conventional example is shown in FIG. In FIG. 2, 2
Is an A / D converter for converting an input analog video signal into digital data, and 10 and 11 are R for image data.
An arithmetic unit that performs GB → Y color difference conversion, or the reverse conversion,
3 is an image memory divided into areas 1 to n for storing a plurality of converted digital image data, 5 is a D / A converter for converting image data into an analog video signal, 6 is overall control, image processing Is a CPU that performs.

When processing such as cutting out an image,
It may be more advantageous to convert to the Y (luminance) -color difference format than the RGB format. This conversion can be realized by performing a 3 × 3 matrix calculation for each pixel. A dedicated LSI for such calculations has been developed,
For example, there is BT281 from Brook Tree. By using this, for RGB

[0004]

[Equation 1]

The matrix calculation as described above can be executed, and the RGB data can be converted into Y-color difference data in real time.

A conventional example using such an element will be described in more detail with reference to FIG. First, the A / D converter 2 converts an analog video signal into digital data. Normal,
Here, the data is output in the RGB format. This data is converted into Y-color difference data by the arithmetic unit 10 and stored in the image memory 3. In order to display this converted data on the display, it has to be converted again into a suitable format. Usually the display is in RGB format.
The inverse conversion for that purpose is performed by the arithmetic unit 11. The data converted here is converted into an analog signal by the D / A converter 5 and displayed on the display.

[0007]

In the prior art, two arithmetic units 10 and 11 are arranged in front of and behind the image memory 3 to perform conversion and inverse conversion, respectively. However, when handling a still image, it is converted by the arithmetic unit 10 on the input side and the memory 3
Once stored in, the arithmetic unit 10 is not used in the subsequent processing. Further, the arithmetic unit 11 only performs the inverse transformation for displaying on the display during image processing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image processing apparatus which can reduce the number of arithmetic units to one, and realize both the saving of the mounting space of the entire image processing apparatus and the cost reduction.

[0009]

In order to achieve the above-mentioned object, an image processing apparatus according to the present invention comprises an A / D converting means for converting an input analog video signal into digital data, and the A / D converting means. An image storage unit for storing the output digital image data, an arithmetic unit for performing an operation on the digital image data output from the image storage unit, and a D for converting the digital data output from the arithmetic unit into an analog video signal. In an image processing apparatus including an A / A conversion unit and a control unit that performs overall control and image data processing, a loop that feeds back the output of the image storage unit to an input side is provided, and the arithmetic unit is included in the loop. It is configured to be provided.

[0010]

The A / D conversion means converts the input analog video signal into digital data. The image storage means stores the digital image data output from the A / D conversion means. The arithmetic unit operates on the digital image data output from the image storage means. The D / A converter converts the digital data output from the arithmetic unit into an analog video signal. The control means performs overall control and image data processing.

A loop for feeding back the output of the image storage means to the input side is provided, the arithmetic unit is provided in the loop, and based on the control of the control means,
The arithmetic unit calculates RGB → Y-color difference conversion, or Y-
The calculation of color difference → RGB conversion is selectively executed. As described above, in the image processing device of the present invention, conversion into one arithmetic unit
It is possible to have both functions of inverse conversion.

[0012]

FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, reference numeral 2 denotes an A / D converter that converts an analog video signal input from the terminal 1 into digital data,
Reference numeral 3 is an image memory having areas 1 to n for storing a plurality of converted digital image data, and 4 is an arithmetic unit for performing conversion of RGB → Y-color difference or Y-color difference → RGB on the image data. In the case of the operation example 1 shown in FIG.
Is inserted in the middle of a feedback loop connecting the output and the input of the image memory 3 and is output to the next D / A converter 5.

In the case of operation example 2 shown below, the A / D
It is connected to receive the output of the converter 2. Reference numeral 5 is a D / A converter for converting the image data output from the arithmetic unit 4 into an analog video signal, 6 is overall control, image editing,
It is a CPU that performs processing such as composition, conversion, and cutout.

<Operation Example 1> The analog video signal input to the terminal 1 is converted into digital data by the A / D converter 2, and is temporarily stored in one of the image memories 1 to n of the image memory 3 i (1). ≦ i ≦ n). At this point, the image data is represented in RGB.

After that, the parameters of the arithmetic unit 4 are changed to RGB
→ Set by the CPU 6 for Y-color difference, and the memory area i
The image data stored in 1 is converted through the arithmetic unit 4 and stored in another image memory area j (1≤j≤n, where i ≠ j).

By doing so, the RGB → Y-color difference conversion is reduced to 1
It can be done in frame time. After that, arithmetic unit 4
By re-setting the parameters for the inverse conversion by the CPU 6, the image converted into the Y-color difference is inversely converted into RGB and output through the D / A converter 5, and is edited and combined while referring to the image on the display. , Conversion, cutout, etc. can be performed.

<Operation Example 2> The parameter of the arithmetic unit 4 is C
CPU for setting RGB → Y-color difference by PU6 and inputting the output from the A / D converter 2 directly to the arithmetic unit 4
Controlled by 6. Then, by controlling the output of the arithmetic unit 4 to be stored in any area of the image memory 3, the RG
The Y-color difference format data can be directly loaded into the memory 3 without temporarily storing the B format data in the memory 3. After that, as in the first embodiment, the parameters of the arithmetic unit 4 can be displayed on the display by resetting the parameters for inverse conversion by the CPU 6.

[0018]

As described above, the image processing apparatus of the present invention is
A loop for feeding back the output of the image storage means to the input side is provided, and the arithmetic unit is provided in the loop.
Since the calculation of Y-color difference conversion or the calculation of Y-color difference → RGB conversion is selectively executed, it is possible to allow one arithmetic unit to perform both conversion and inverse conversion functions. Only one computing unit, which requires two, can be used. Therefore, it is very effective in reducing the manufacturing cost, downsizing the device, and reducing the power consumption.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional device.

[Explanation of symbols]

 1 terminal 2 A / D converter 3 image memory 4 arithmetic unit 5 D / A converter 6 CPU

Claims (1)

[Claims] 1. An A / D conversion means for converting an input analog video signal into digital data, an image storage means for storing the digital image data output from the A / D conversion means, and an image storage means An arithmetic unit for performing an arithmetic operation on the output digital image data, a D / A conversion unit for converting the digital data output from the arithmetic unit into an analog video signal, and a control unit for performing overall control and image data processing. An image processing apparatus provided with a loop for feeding back an output of the image storage unit to an input side, and the arithmetic unit provided in the loop.