KR100205333B1 - Color differentiating transform apparatus - Google Patents

Abstract

The present invention relates to a color difference signal converting apparatus, comprising: an image processing unit (400) for receiving a digital image signal, generating and outputting a luminance signal and respective color difference signals, and a top of a color difference signal output from the image processing unit (400). An inverter (INV) for receiving a bit and inverting the bit; Compression decompression unit 500 for receiving the luminance signal and the color difference signal output from the image processing unit 400 and the signal output from the inverter (INV) to receive or compress, or to restore the original signal from the compressed data to output And an encoder 700 which receives the digital luminance signal and the color difference signal output from the image processing unit 400, the inverter INV, or the compression recovery unit 600, and converts and outputs an analog image signal. In a video compression restoring system for digital still cameras, camcorders, CD cameras, etc., a normal compression and restoration even when the representation value of an image processed output signal and the representation value of an input signal subjected to image compression are different The present invention relates to a color difference signal converting apparatus capable of performing the same.

Description

Color difference signal converter

1 is a block diagram applying a general digital signal processing processor,

2 is a block diagram showing the function of the color signal processor in FIG.

3 is a waveform diagram of each part in FIG.

4 is a block diagram to which an image compression and recovery system of a conventional digital still camera is applied.

5 is a block diagram to which the chrominance signal converting apparatus according to the first embodiment of the present invention is applied.

6 is a block diagram to which the color difference signal converting apparatus according to the second embodiment of the present invention is applied.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chrominance signal converter, and more particularly, an image compression restoring system for use in digital still cameras, camcorders, charge coupled device (CCD) cameras, and the like. The present invention relates to a chrominance signal converting apparatus capable of performing normal compression and reconstruction even when a representation value of an image processed output signal and a representation value of an input signal subjected to image compression are different.

Conventionally, analog signal processing has been performed in processing video signals. However, with the development of digital technology, digital video signal processing using a micro computer has been performed.

In addition, with the development of a digital signal processor (hereinafter referred to as 'DSP'), the speed of development is increasing.

In the above, DSP refers to a special microprocessor that performs signal processing digitally.

Digital signal processing performs filter operation, modulation and demodulation operation, spectral analysis, linear prediction, etc. by algebraic calculation of digital values, and it is possible to realize a function that was difficult to realize in conventional analog signal processing with high accuracy and high stability. Have

The DSP is used in digital still cameras, camcorders, and CD cameras, or cameras of various video applications, such as video signal processing and various automatic functions, data detection, and timing generation. TG, Timing Generator, Synchronizing Signal Generator (SSG), and Superimpose for Title Mixing.

In the above, the automatic function refers to auto exposure (AE), auto focus (AF), auto brightness (AWB), and auto white balance (AWB).

Hereinafter, a general DSP will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram applying a general DSP, FIG. 2 is a block diagram showing the function of the color signal processor in FIG. 1, and FIG. 3 is a waveform diagram of each part in FIG.

As shown in FIG. 1 and FIG. 2, a general DSP configuration includes a signal separation unit that receives a digital video signal and separates and outputs the luminance signal Y and the respective color signals R, G, and B ( 10); A luminance signal processing unit 20 which receives the luminance signal Y output from the signal separation unit 10, converts the luminance signal Y into a signal suitable for output, and generates and outputs a digital luminance signal Y '; A color signal processor (30) which receives the color signals (R, G, B) output from the signal separation unit (10), generates and outputs the digital chroma signal (C) and the color difference signals (R-Y, B-Y); A timing generator 40 for generating and outputting a clock signal (clock, CLK) necessary for the operation of the signal processor 10, the luminance signal processor 20, and the color signal processor 30; The signal processing unit 10, the luminance signal processing unit 20, and the synchronization generation unit 50 generating and outputting a synchronization signal for synchronizing the operations of the color signal processing unit 30.

The color signal processor 30 may include a color difference signal processor 31 that receives color signals R, G, and B output from the signal processor 10, and generates and outputs color difference signals RY and BY. ; A first adder (AD32) which receives two color difference signals (R-Y, B-Y) output from the color difference signal generator (31) and alternately outputs two signals; A burst generator 33 for generating and outputting a burst signal; A balance modulator (34) for receiving a burst signal output from the burst generator (33) and performing balanced modulation on the burst signal; The second adder AD35 receives a signal output from the first adder AD32, receives a signal output from the balance modulator 34, and generates and outputs a complex color signal.

The operation of a general DSP as described above is as follows.

The signal separation unit 10 receives a digital image signal, separates the luminance signal Y into respective color signals R, G, and B, and outputs the luminance signal processing unit 20 from the signal separation unit 10. The luminance signal Y is input and converted into a signal suitable for output to generate and output a digital luminance signal Y ', and the color signal processor 30 outputs the color signal output from the signal separator 10. It receives the R, G, and B, generates and outputs the digital chroma signal C and the color difference signals RY and BY.

The timing generator 40 generates and outputs a clock signal necessary for the operation of the signal processor 10, the luminance signal processor 20, and the color signal processor 30, and the synchronization generator 50 generates the clock signal. A synchronization signal for synchronizing the operations of the signal processor 10, the luminance signal processor 20, and the color signal processor 30 is generated and output.

The configuration of the color signal processor 30 shown in FIG. 2 will now be described in detail.

The color difference signal generator 31 receives the color signals R, G, and B output from the signal separation unit 10, generates and outputs the color difference signals RY and BY, and the first adder AD32 The two color difference signals RY and BY outputted from the color difference signal generator 31 are input and alternately output the two signals.

The clock signal output from the timing generator 40 is shown in FIG. 3A, and in order to alternately output the two signals by the first adder AD32, the clock signal of FIG. Use the same signal as (b).

As shown in (c) of FIG. 3, each bit of the luminance signal Y is output one bit in synchronization with the main clock signal CLK, and appears as shown in (b) of FIG. Each bit of (RY, BY) is output one bit for every half period of the half-divided signal CLKD as shown in (b) of FIG. 3, and is shown as (d) of FIG.

On the other hand, the burst generator 33 generates and outputs a burst signal, and the balance modulator 34 receives the burst signal output from the burst generator 33 and balance modulates and outputs the second adder AD35. ) Receives a signal output from the first adder AD32, receives a signal output from the balance modulator 34, and generates and outputs a composite color signal.

However, many developments of digital still cameras using a DSP operating as described above have been made, and such a system requires a technique for compressing and restoring a video signal.

Hereinafter, a compression restoring system of a conventional digital still camera will be described with reference to the accompanying drawings.

4 is a block diagram to which an image compression reconstruction system of a conventional digital still camera is applied.

As shown in FIG. 4, the configuration of the image decompression system of the conventional digital still camera receives the digital image signal Din, generates the luminance signal Y and the respective color difference signals Cr and Cb. An image processor 100 for outputting; A compression decompression unit 200 for receiving the luminance signal Y and the color difference signals Cr and Cb emitted from the image processing unit 100 and compressing them, or restoring and outputting the original signal from the compressed data; ; The encoder 300 receives the digital luminance signal Y and the color difference signals Cr and Cb output from the image processing unit 100 or the compression decompression unit 200, converts the analog luminance signal Ain into an analog image signal Ain, and outputs the same. Consists of

The operation of the compression recovery system of the conventional digital still camera made as described above is as follows.

The image processor 100 receives the digital image signal Din, generates and outputs a luminance signal Y and respective color difference signals Cr and Cb, and the compression recovery unit 200 outputs the image processor 100. The luminance signal Y and the respective color difference signals Cr and Cb are output from the compressed signal, or the original luminance signal and the color difference signal are restored from the compressed data.

The luminance signal Y and the two color difference signals Cr and Cb are formatted and output in a ratio of 4: 2: 2.

The encoder 300 receives the digital luminance signal Y and the color difference signals Cr and Cb output from the image processing unit 100 or the decompression unit 200, such as a television and a monitor. It converts and outputs the analog video signal (Aout) which can be output on the screen for the eyes to see.

Meanwhile, when the encoder 300 directly converts a signal output from the image processing unit 100 into an analog image signal, a dynamic image may be obtained, and the signal output from the decompression unit 200 may be obtained. When converted into an analog video signal, a still image can be obtained.

In general, the decompression unit 200 that performs image compression requires a luminance signal Y and two digital color difference signals Cr and Cb having a 4: 2: 2 format. This is necessary for the efficient use of memory and the optimization of image compression and reconstruction.

However, the color difference signals RY and RB output from the DSP of FIG. 1 are 16-bit modes, that is, digital signals that are alternately outputted with the digital luminance signal Y, and the representation method and data range thereof. ) Is shown in Table 1 below.

In FIG. 4, the signals required for the input of the decompression unit 200 are color difference signals Cr and Cb alternately displayed with the luminance signal Y, and the expression method and the data range are shown in Table 2.

That is, since the representation of the digital image output value processed by the image signal and the representation of the digital image input value to be input for image compression are different, the difference of the data range appears, and is specifically shown in Table 3 below.

As described above, the conventional technology inevitably uses a DSP having a data range as shown in Table 1 and a compression recovery unit having a data range as shown in Table 2 for reasons other than video signal processing. There is a problem that the correct signal processing is not performed as the value range is different.

Accordingly, an object of the present invention is to solve the conventional problems as described above. Even when the expression value of the input signal for performing image compression used in a digital still camera, a camcorder, and a CD camera is different, normal compression and restoration are performed. An object of the present invention is to provide a color difference signal converter capable of doing so.

A configuration of the present invention for achieving the above object comprises: image processing means for receiving a digital image signal, generating and outputting a luminance signal and each color difference signal; Signal conversion means for converting and outputting a representation method of each color difference signal output from the image processing means; Compression decompression means for receiving the luminance signal outputted from the image processing means and the signal outputted from the signal conversion means, receiving the compressed signal, or restoring and outputting the original signal from the compressed data; And an image processing unit, and encoding unit for receiving the digital luminance signal and the color difference signal output from the signal conversion unit or the compression recovery unit, converting the analog image signal into an analog image signal, and outputting the analog image signal.

Another aspect of the present invention for achieving the above object is an image processing means for receiving a digital image signal, and generates and outputs a luminance signal and each color difference signal; Signal inverting means for converting and outputting a representation method of each color difference signal output from said image processing means; And an encoding unit for receiving the digital luminance signal and the chrominance signal output from the image processing unit and the signal inverting unit, converting the image into an analog image signal and outputting the analog image signal.

Hereinafter, with reference to the accompanying drawings will be described a first preferred embodiment of the present invention can be easily carried out.

5 is a block diagram to which the color difference signal converting apparatus according to the first embodiment of the present invention is applied.

As shown in FIG. 5, the configuration of the color difference signal converting apparatus according to the first embodiment of the present invention receives the digital image signal Din, and receives the luminance signal Y and the respective color difference signals RY and BY. An image processor 400 for generating and outputting the generated text; An inverter (INV) for receiving the most significant bits of the color difference signals R-Y and B-Y output from the image processor 400 and inverting them to output the inverted bits; The luminance signal Y and the color difference signals Cr and Cb output from the image processor 400 and the signal output from the inverter INV are input and compressed, or the original signal is restored from the compressed data. An output compression decompression unit 500; The digital luminance signal Y and the respective color difference signals RY and BY output from the image processing unit 400, the inverter INV, or the decompression unit 500 are received and converted into an analog image signal Auto. It consists of an encoder 600 for outputting.

Operation of the first embodiment of the present invention made as described above is as follows.

When an analog-digital converted image signal Din is inputted so that the analog signal photoelectrically converted by the CD is suitable for image processing, the image processing unit 400 receives the image signal Din and receives the luminance signal Y. And generate and output the respective color difference signals RY and BY.

The luminance signal Y and the color difference signals R-Y and B-Y are output in a 4: 4: 4 format.

At this time, the output representation range of the 8-bit digital luminance signal Y is an unsigned magnitude signal '0 to 255', and the output representation range of the 8-bit digital chrominance signal RY and BY is two's complement '-128 to. +127 '.

The inverter INV receives the most significant bits of the color difference signals R-Y and B-Y output from the image processor 400 and inverts them.

The decompression unit 500 may output a luminance signal Y and a color difference signal Cr and Cb output from the image processing unit 400, and a signal output from the inverter INV. In order to store on a recording medium such as a hard disk or a floppy disk, the compressed signal is restored or the original signal is restored from the compressed data.

The encoder 600 receives the digital luminance signal Y and the respective color difference signals RY and BY output from the image processing unit 400 and the inverter INV or the decompression unit 600, and receives a TV, It converts and outputs analog video signal (Aout) which can be output on the screen for the human eye to see.

However, the expression range of the 8-bit digital luminance signal Y input to the decompression unit 500 and the encoder 600 is an unsigned magnitude signal '0 to 255' and the 8-bit digital color difference signals Cr and Cb. The expression range of is also the unsigned magnitude value '0 to 255'.

Therefore, the expression values of the 8-bit digital color difference signals RY and BY outputted from the image processor 400 and the digital color difference signals Cr and Cb inputted to the decompression unit 500 and the encoder 600 are determined. The inverter INV plays a role.

That is, in Table 3, when '128' is added to the signal represented by the two's complement magnitude value, the signal is expressed as the unsigned magnitude value.

Therefore, in the case of an 8-bit signal, inverting the most significant bit of the signal represented by the two's complement magnitude value becomes as represented by the unsigned magnitude value.

For example, if the 8-bit signal value represented by two's complement is '0', that is, '0000 0000', inverting the most significant bit of the signal results in '1000 0000', which is '128' as an unsigned magnitude value. 'Becomes.

If the 8-bit signal value represented by two's complement is '-2', that is, '1111 1110', inverting the most significant bit of the signal results in '0111 1110', which is '126' as an unsigned magnitude value. Becomes

That is, by inverting the most significant bit of 8-bit data represented by two's complement, it is possible to convert to an unsigned magnitude value.

The decompression unit 500 may compress data converted by the inverter INV and store a memory card, a hard disk, a floppy disk, or the like on a recording medium, and the encoder 600 may convert the signal into an analog image. It can be converted into a signal and output to a monitor or television.

On the other hand, when the encoder 600 converts the signal output from the image processor 400 directly into an analog image signal, a video can be obtained, and the signal output from the decompression unit 500 is converted into an analog image signal. By converting, a still image can be obtained.

Hereinafter, with reference to the accompanying drawings will be described a second preferred embodiment of the present invention can be easily carried out.

6 is a block diagram to which the color difference signal converting apparatus according to the second embodiment of the present invention is applied.

As shown in FIG. 6, the configuration of the color difference signal converting apparatus according to the second embodiment of the present invention receives the digital image signal Din, and receives the luminance signal Y and the respective color difference signals RY and BY. An image processor 700 for generating and outputting the generated text; A signal inverting unit 800 for receiving the most significant bits of the color difference signals R-Y and B-Y output from the image processing unit 400 and inverting them to output them; An encoder that receives the digital luminance signal Y output from the image processing unit 700 and the color difference signals Cr and Cb output from the signal inverting unit 800, converts them into analog image signals Auto, and outputs them. It consists of 900.

The signal inverting unit 800 may include a first inverter INV1 for receiving the most significant bit signal of the first color difference signal R-Y output from the image processing unit 700 and inverting the same; The second inverter INV2 receives the most significant bit signal of the second color difference signal B-Y output from the image processing unit 700 and inverts and outputs it.

The operation of the second embodiment of the present invention made as described above is as follows.

When an analog-digital converted image signal Din is inputted so that the analog signal photoelectrically converted by the CD is suitable for image processing, the image processing unit 700 receives the image signal Din. A luminance signal Y having a range of? And a first color difference signal RY and a second color difference signal BY having a range of '-128 to +127' are generated and output.

The luminance signal Y, the first color difference signal R-Y and the second color difference signal B-Y are output in a 4: 4: 4 format.

The first inverter INV1 and the second inverter INV2 of the signal inverting unit 800 respectively represent the most significant bits of the first color difference signal RY and the second color difference signal BY output from the image processing unit 700. Invert and pass the remaining bits as they are.

Accordingly, the expression values of the first color difference signal R-Y and the second color difference signal B-Y are converted into '0 to 255' from the image processor 700.

Therefore, an 8-bit digital first color difference signal RY and a second color difference signal BY outputted from the image processor 700, and a digital first color difference inputted to the decompression unit 500 and the encoder 600. Since the expression values of the signal Cr and the second color difference signal Cb are matched by the signal inverting unit 800, there is no problem in signal processing in the encoder 900.

The encoder 900 receives the luminance signal Y output from the image processor 700, the first color difference signal Cr and the second color difference signal Cb output from the signal inverting unit 800, It is converted into an analog video signal (Aout) that can be output on the screen for viewing by human eyes such as a television and a monitor.

As shown above, when the representation range of the data output from the image processing unit at the front end and the representation range of the required data by the input of the encoder at the rear end do not match, only the most significant bit is inverted to configure the system desired by the user. can do.

Therefore, the integrated circuit must be used inevitably as the front end so that the desired function can be implemented in the system, and the rear end can effectively cope with the case inevitably used to implement any other function.

Therefore, the effects of the present invention operating as described above are the expression values of the image-processed output signal and the input signal for image compression in the image compression restoration system for use in digital still cameras, camcorders, CD cameras, and the like. It is to provide a color difference signal converter that can be compressed and restored normally even if the expression value of.

Claims (4)

Image processing means for receiving a digital image signal and generating and outputting a luminance signal and respective color difference signals; Signal conversion means for converting and outputting a representation method of each color difference signal output from said image processing means; Compression decompression means for receiving the luminance signal outputted from the image processing means and the signal outputted from the signal conversion means, receiving the compressed signal, or restoring and outputting the original signal from the compressed data; A color difference signal conversion device comprising: an image processing means, encoding means for receiving a digital luminance signal and a color difference signal output from a signal conversion means or a compression recovery means, and converting and outputting an analog image signal; The color difference signal conversion device according to claim 1, wherein the signal conversion means comprises an inverter (INV) for inverting and outputting the most significant bit of the color difference signal output from the image processing means. Image processing means for receiving a digital image signal and generating and outputting a luminance signal and respective color difference signals; Signal inverting means for converting and outputting a representation method of each color difference signal output from said image processing means; Digital output from said image processing means and signal inversion means Color difference signal conversion device, characterized in that consisting of the encoding means for receiving the luminance signal and the color difference signal, converts it into an analog video signal and outputs it. 4. The apparatus of claim 3, wherein the signal inverting means comprises: a first inverter (INV1) for receiving the most significant bit signal of the first color difference signal output from the image processing means and inverting the same; And a second inverter (INV2) for receiving the most significant bit signal of the second color difference signal output from the image processing means and inverting the same.