KR100293369B1 - Digital video compression coding and decoding system using shape adaptive selection and thereof method - Google Patents

Abstract

The present invention relates to a digital image compression encoding and decoding apparatus using a shape adaptive selection used in a communication apparatus and a multimedia apparatus using a video compression technique, and a method thereof, and to a digital image compression encoding using a shape adaptive selection according to the present invention. And a decoding apparatus and a method thereof, by using a shape information of an image signal block to be encoded, first converting the image signal block to a direction including a large number of pixels, and then performing a transformation to the other direction to increase encoding efficiency. In the process of receiving an encoded signal and decoding the encoded signal, an inverse transform may be performed in the reverse order of the transform using shape information reconstructed to increase decoding efficiency.

Description

Digital video compression encoding and decoding apparatus using shape adaptive selection and its method {DIGITAL VIDEO COMPRESSION CODING AND DECODING SYSTEM USING SHAPE ADAPTIVE SELECTION AND THEREOF METHOD}

The present invention relates to a digital image compression encoding and decoding apparatus and method using shape adaptive selection used in a communication apparatus and a multimedia apparatus using an image compression technique.

In general, in a method of compressing and encoding a digital image, a transform coefficient (TRANSFORM COEFFICIENT; hereinafter referred to as a transform coefficient) using an orthogonal transform (ORTHOGONAL TRANSFORM) method is used. ) And then the conversion coefficient is encoded. The most widely used method is ISO / IEC JPEG, which is a standardized still image compression coding standard, and ISO / IEC MPEG, ITU-T, which is a standardized video compression code. It is also widely used in international standards for all digital compression encoding such as 261 and H.263.

Recently, an object-based coding method, which is a method of encoding an image signal block to be encoded by using shape information into an object and a non-object or a part to be encoded and a part not to be encoded, is encoded. It is a trend.

Among conventional content-based coding schemes, the converter class compressor method converts an input image signal block by a transform method controlled by SHAPE INFORMATION (hereinafter, referred to as shape information) and quantizes the transform coefficient. After quantization, the quantized transform coefficient is transmitted by VARIABLE LENGTH CODING, and the reverse process is used to recover the signal.

In this case, the shape information may be separated into a background and an object to be encoded in compression encoding of the image signal block, and the separated background and object screens may be independently encoded.

In the conventional video compression encoding and decoding system, as shown in FIG. 1, an encoding apparatus for encoding an input image signal block by using a compression technique, and receiving the encoded signal, receives a signal through an inverse process of encoding. It consists of a decoding device to recover.

The encoding apparatus includes a subtractor 1 for outputting a prediction error signal block by subtracting an input image signal block and a reconstructed image signal block, an additional information signal (eg, shape information) and a variable length coded shape to assist in encoding. A sub information encoder 9 for outputting an information signal and a predictive error signal block are received by the subtractor 1, and shape information is received by the sub information encoder 9 and a transform coefficient converted by a specific conversion method is output. An orthogonal transformer 2, a quantizer 3 for receiving a transform coefficient from the orthogonal transformer 2, and converting the transform coefficient into a quantized transform coefficient block, and a quantized transform coefficient block from the quantizer 3 The variable length coder 8 converts the variable length coded transform coefficient signal, the variable length coded signal from the variable length coder 8 and the shape information from the side information encoder 9. The multiplexer 11 multiplexes the two signals and transmits the two signals to the transmission medium 12.

On the other hand, the first inverse quantizer (4) for receiving and inverse quantization of the transform coefficient block quantized by the quantizer (3), and the inverse quantized transform coefficient block in the first inverse quantizer (4) An inverse orthogonal transformer 5 that receives shape information from the additional information encoder 9 and converts the shape information into a signal block that is inversely orthogonally transformed; a signal block that is inversely orthogonally transformed in the inverse orthogonal transformer 5; An adder 6a which adds the reconstructed video signal blocks stored in (7) to reconstruct the video signal blocks, and receives and stores the signals added by the adder 6a to the subtractor 1; A first memory 7 for outputting a video signal block is further configured.

The decoding apparatus may further include: a demux unit for receiving a variable length coded signal from the multiplexer 11 through a transmission medium 12 and outputting a variable length coded shape information signal and a variable length coded transform coefficient signal; 13), a decoder 15 for receiving a variable length coded transform coefficient signal from the demux 13 and converting the transform coefficient signal into a quantized transform coefficient block, and a quantized transform coefficient block received from the decoder 15 A second inverse quantizer 16 for converting into a quantized transform coefficient block, an additional information decoder 14 for restoring shape information encoded with variable length in the demux unit 13, and the second inverse quantizer ( 16, an inverse orthogonal transformer 17 for receiving the dequantized transform coefficient block and simultaneously receiving shape information from the side information decoder 14 and outputting an inverse orthogonal transformed signal block, and in the inverse orthogonal transformer 17 Inverse orthogonal An adder 6b for receiving a previously restored video signal block stored in a second memory 18 to be described later and adding the two signals to output a restored video signal block, and the adder 6b. And a second memory 18 for storing the reconstructed video signal block outputted from the < RTI ID = 0.0 >

The shape information is information that divides an image into an object region and a non-object region (background). The shape information enables signal processing centering on an object region instead of the entire image in an encoder and a decoder. It takes the form of a binary mask that allows different values for pixels (backgrounds) rather than objects.

The operation of the conventional video compression encoding and decoding apparatus having the above configuration will be described.

First, when the subtractor 1 outputs the prediction error signal block obtained by subtracting the video signal block and the reconstructed video signal block, the quadrature converter 2 receives the prediction error signal block and at the same time the additional information encoder 9 receives the prediction error signal block. It receives shape information and outputs the transform coefficient converted by the orthogonal transform method.

In this case, the subtractor 1 may output the current input signal as it is without prediction from the signal of the first memory 7 as well as the prediction error between the signal predicted from the first memory 7 and the current input signal. To this end, the value stored in the first memory 7 may be initialized to 0 to make the signal from the subtractor 1 equal to the input image signal.

In this case, the quantizer 3 receives the transform coefficient from the quadrature converter 2 and transforms the transform coefficient into a quantized transform coefficient block. The variable length encoder 8 receives the quantized transform coefficient block and converts the variable length coded transform into a quantized transform coefficient block. The signal is converted into a coefficient signal, and the variable length coded signal is output to the multiplexer 11.

The multiplexer 11 receives the variable length coded transform coefficient signal and the variable length coded shape information from the side information encoder 9 and multiplexes the two signals to output them through the transmission medium 12.

Subsequently, the demux 13 receives the encoded signal from the transmission medium 12 and outputs variable length coded shape information and a variable length coded transform coefficient block.

The decoder 15 receives the variable length coded signal from the demux 13 and converts the quantized transform coefficient block into a quantized transform coefficient block, and the second inverse quantizer 16 receives the quantized transform coefficient block and dequantizes it. Output the transform coefficient block.

The inverse orthogonal transformer 17 receives the inverse quantized transform coefficient block from the second inverse quantizer 16 and receives shape information from the additional information decoder 14, and outputs an inverse orthogonal transformed signal block. 6b receives an inversely orthogonally transformed signal block and simultaneously receives a previously restored video signal block from the second memory 18, adds the two signals, and outputs the restored video signal block.

On the other hand, the transform coefficient block quantized by the quantizer 3 is input to the first inverse quantizer 4 and converted into a dequantized transform coefficient block, and the signal is input to the inverse orthogonal transformer 5.

At the same time, the shape information is input from the side information encoder 9 to the inverse orthogonal transformer 5, whereby the inverse orthogonal transformer 5 outputs the inverse orthogonal transformed signal block, and the adder 6a is the inverse. The orthogonal transformed signal block and the image signal block previously reconstructed in the first memory 7 are added to be converted into a reconstructed image signal block, and the image signal block is stored in the first memory 7 to reduce the subtractor ( Is entered in 1).

The additional information decoder 14 outputs the reconstructed shape information, and the second image 18 stores the reconstructed input image signal block for prediction.

On the other hand, the conversion method used in the quadrature converter 2 will be described with reference to Figs. 2A to 2E. Only the hatched portion is converted to the portion to be encoded and encoded. First, when the video signal block is input (FIG. 2A), the input signal is aligned with respect to the upper end of the unit block (FIG. 2B), and DCT transformed in the vertical direction (FIG. 2C).

Subsequently, when alignment is completed with respect to the left side, DCT conversion is performed in the horizontal direction (Fig. 2D) to obtain a final converted signal (Fig. 2E).

3A to 3C are diagrams for explaining that the transform coefficients are different according to the direction orthogonal transformed by the orthogonal transformer 2 of FIG. 1, and FIG. 3A is a signal block input to the orthogonal transformer 2, wherein the number The part without indicates the part without encoding, i.e., the part which does not perform encoding into the background area, and the part with the number is converted and encoded.

3B is a conversion coefficient when the first orthogonal transformation is performed in the longitudinal direction and then the orthogonal transformation is performed in the horizontal direction, and FIG.

Here, comparing FIG. 3B and FIG. 3C, it can be seen that different results, that is, different conversion coefficients are generated according to the orthogonal transformation direction order.

Looking at the details, the input signal block having a high similarity in the horizontal direction as shown in FIG. 3A is orthogonally transformed in the horizontal direction first and then orthogonally transformed in the vertical direction. As a result of FIG. 3B orthogonal transformation, the energy concentration is higher than that of FIG. 3B. Since only a small number of transformation coefficients are encoded, a higher compression performance is obtained.

That is, when orthogonal transformation is performed first in the vertical direction and then transversely orthogonally transformed as shown in FIG. 3B, 12 different values of coefficients of change must be encoded. Encoding efficiency can be increased because only coefficients having different values are encoded.

Conventionally, as shown in FIGS. 3A to 3C, without considering the similarity of an input signal that is orthogonally transformed, a method of unilaterally transforming after transverse orthogonal transformation or using a method of transverse orthogonal transformation after vertical orthogonal transformation is used. There was a problem in that an optimum conversion result could not be obtained for the characteristics of the input signal.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide an apparatus and method for digital video compression encoding and decoding using shape adaptive selection to increase compression encoding efficiency.

In order to achieve the above object, a digital image compression encoding apparatus using shape adaptive selection according to the first embodiment of the present invention is an apparatus for compression encoding by receiving an image signal block by performing orthogonal transformation using shape information. A mode controller for receiving a shape information of an image signal block to be analyzed and outputting a mode control signal for first performing orthogonal transformation in a direction having a larger number of pixels by analyzing the number of pixels in the horizontal and vertical directions, and in the mode controller An orthogonal transformation means for receiving a mode control signal and performing orthogonal transformation in response thereto.

In order to achieve the above object, a digital image compression encoding method using shape adaptive selection according to the first embodiment of the present invention is a method of compression encoding by receiving an image signal block and performing orthogonal transformation using shape information. The mode control signal is inputted by analyzing the number of pixels in the horizontal and vertical directions by receiving the shape information of the image signal block to be subjected to the orthogonal transformation in the direction having the larger value among the maximum horizontal pixels and the maximum vertical pixels. And an orthogonal transformation step of performing orthogonal transformation by the mode control signal outputting step and the mode control signal output in the mode control signal generating step.

In order to achieve the above object, a digital image compression decoding apparatus using shape adaptive selection according to the first embodiment of the present invention is an apparatus for decoding orthogonally transformed compressed coded information, and reconstructing a video block to be currently decoded. And a mode controller for determining a number of pixels in the horizontal and vertical directions and outputting a mode control signal to first inversely orthogonally convert in a direction having a smaller number of pixels. Inverted orthogonal transformation means for receiving an input and performing an inverse orthogonal transformation accordingly.

In order to achieve the above object, a digital image compression decoding method using shape adaptive selection according to the first embodiment of the present invention is a method of decoding orthogonally transformed compressed coded information, and reconstructing a video block to be currently decoded. Mode control outputting a mode control signal to first receive inverse orthogonal transformation in the direction having the smaller value among the maximum horizontal pixels and the maximum vertical pixels by analyzing the number of pixels in the horizontal and vertical directions And an inverse orthogonal transformation step for performing inverse orthogonal transformation by the mode control signal output in the mode control signal generation step.

In order to achieve the above object, a digital image compression encoding apparatus using shape adaptive selection according to a second embodiment of the present invention is an apparatus for performing compression encoding by receiving an image signal block and performing orthogonal transformation using shape information. A mode controller for determining a conversion method by receiving the shape information of the image signal block to be compared and comparing the number of pixels of the four edges of the image signal block, and outputting any one of the corresponding mode control signals 1 to 4, in the mode controller It characterized in that the orthogonal conversion means for receiving the mode control signal according to the orthogonal transformation after aligning or symmetrically shifting the input image signal block.

In order to achieve the above object, a digital image compression encoding method using shape adaptive selection according to a second embodiment of the present invention is a method of compression encoding by receiving an image signal block by orthogonal transformation using shape information. A mode control signal generating step of receiving the shape information of the video signal block to be compared and comparing the number of pixels of the four corners of the video signal block and outputs any one of the mode control signals 1 to 4 corresponding thereto, and the mode control signal generating step When the mode control signal 1 is output due to the largest number of pixels on the bottom of the four edges of the video signal block inputted from, the pixels of the input video signal block corresponding to the boundary of the shape information are arranged at the top and horizontally. To the left column of the block, shifting in the direction, and then performing horizontal and vertical orthogonal transformations in order. Claim characterized by consisting of a first conversion step.

In order to achieve the above object, a digital image compression / decoding apparatus using shape adaptive selection according to a second embodiment of the present invention is an apparatus for decoding orthogonally transformed compressed coded information, and reconstructing a video block to be currently decoded. And a mode controller for determining an inverse conversion method by comparing the number of pixels of four edges of the image signal block and outputting a mode control signal according to the received shape information. The inverse orthogonal transformation means for performing the inverse orthogonal transformation inverse to the conversion process and rearranging the position of the original video signal.

In order to achieve the above object, a digital image compression decoding method using shape adaptive selection according to a second embodiment of the present invention is a method of decoding orthogonally transformed compressed coded information, and reconstructing a video block to be currently decoded. And a mode control signal generation step for determining an inverse conversion method by comparing the number of pixels of four edges of the image signal block and outputting a mode control signal accordingly. In response to the input, the orthogonal conversion process is performed inversely orthogonally, and then inversely transformed to the position of the original video signal.

1 is a control block diagram of a video compression encoding and decoding apparatus according to the prior art;

2A to 2E are diagrams illustrating a process of orthogonal transformation using shape information in the orthogonal transformer of FIG. 1;

3A to 3C are diagrams for explaining that conversion coefficients are different according to a direction orthogonal transformation in the orthogonal transformer of FIG. 1;

4 is a control block diagram of a digital image compression encoding and decoding apparatus using shape adaptive selection according to the first and second embodiments of the present invention;

FIG. 5 is a view showing Embodiment 1 of the mode controller of FIG. 4;

6 is a view showing an example of input shape information when performing 8 × 8 block unit encoding;

FIG. 7 is a view showing Embodiment 2 of the mode controller of FIG. 4; FIG.

8A to 8D illustrate mode control signals 1, 2, 3, and 3 from the mode controller according to an input image signal block in a digital image compression encoding and decoding apparatus using shape adaptive selection according to a second embodiment of the present invention. 4 shows a conversion process in the orthogonal conversion means.

<Explanation of symbols for main parts of the drawings>

100, 100 ', 400, 400': Mode controller 110, 410: Horizontal counter

120.420: portrait counter 130, 430: comparator

140, 440: boundary pixel measuring means 150, 450: comparator

200, 200 ': orthogonal transformation means 300, 300': first inverse orthogonal transformation means

500, 500 ': second inverse orthogonal transformation means

Hereinafter, an apparatus and method for digital video compression encoding and decoding using shape adaptive selection according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 4 is a control block diagram of a digital image compression encoding and decoding apparatus using shape adaptive selection according to the first and second embodiments of the present invention.

An encoding apparatus according to a first embodiment of the present invention will be described with reference to FIG. 4.

The encoding apparatus according to the first embodiment of the present invention includes a subtractor (1), an additional information encoder (9), a mode controller (100), orthogonal transform means (200), a quantizer (3), a variable length encoder (8), It consists of a multiplexer 11, a first inverse quantizer 4, a first inverse orthogonal transformation means 300, an adder 6a and a first memory 7.

The subtractor 1 subtracts the video signal block and the reconstructed video signal block to output the prediction error signal block, and the side information encoder 9 encodes the reconstructed shape information and the variable length code to help the encoding. It outputs shape information.

The subtractor 1 may output the current input signal as it is without prediction from the signal of the first memory 7 as well as a prediction error between the signal predicted from the first memory 7 and the current input signal. To this end, the value stored in the first memory 7 may be initialized to 0 to make the signal from the subtractor 1 equal to the input image signal.

The mode controller 100 receives shape information from the code information encoder 9 and analyzes pixels of the shape information and outputs a mode control signal corresponding to the shape information.

Referring to FIG. 5, the horizontal counter 110 counts the number of horizontal pixels of shape information input from the additional information encoder 9, and the vertical counter 120 measures the additional information encoder ( It counts the number of vertical pixels of shape information input in 9). The comparator 130 compares the number of horizontal pixel counters and the number of vertical pixel counters output from the horizontal counter 110 and the vertical counter 120 to select a direction showing more pixels and selects the direction in the selected direction. It outputs a mode control signal for performing the conversion. This is because it is advantageous in terms of coding efficiency to use a method for converting a large number of pixels as described above in the case of transforming an image signal block in a predetermined orthogonal transform order, so that the transform is performed first in a direction in which the number of pixels is high. In this case, various methods for counting the number of pixels may be used. For example, a method of using the number of pixels in a row having the maximum horizontal pixel number and the number of pixels in a column having the maximum vertical pixel number, A method of using the result divided by the maximum number of pixels in the vertical direction, or a method of measuring the number of pixels in the horizontal and vertical directions by appropriately weighting them in consideration of the conversion gain for the number of conversion unit pixels may be used. .

6 is a diagram illustrating an example of shape information input when 8 × 8 block unit encoding is performed. It is assumed that a hatched portion corresponds to an object and only this portion is an encoding target. A method of outputting a mode control signal after measuring the number of pixels using FIG. 6 will be described.

First, a description will be made of a method of using a maximized value as the first method of measuring the number of pixels in the shape information. In FIG. 6, it can be seen that there are seven maximized pixels in the horizontal direction. Six. Therefore, in the case of the block in which the shape information as shown in FIG. 6 is input, the comparator 130 generates a mode control signal to first perform orthogonal transformation in the horizontal direction and then perform orthogonal transformation in the vertical direction.

The second method of measuring the number of pixels is to divide the number of pixels in the shape information into pixels for each direction by dividing the number of pixels in the shape information. In FIG. 6, the number of pixels in the shape information is 17, and the maximum number of pixels in the horizontal direction is Seven, with a maximum of six in the vertical direction. As a result, the number of pixels in the horizontal direction is 17/7, the number of pixels in the vertical direction is 17/6, and the number of pixels in the vertical direction is larger than the number of pixels in the horizontal direction. Outputs the mode control signal to perform the conversion in the horizontal direction. The advantage of the second method over the first method is that it guarantees to convert first to the direction having the largest number of pixels in the horizontal and vertical directions.

The orthogonal transformation means 200 receives the prediction error signal block from the subtractor 1, and the orthogonal transformation mode is controlled by the mode control signal output from the mode controller 100 to perform orthogonal transformation. It outputs coefficients.

The quantizer 3 receives a transform coefficient from the orthogonal transform means 200 and converts the transform coefficient into a quantized transform coefficient block, and the variable length coder 8 quantizes the transform coefficient from the quantizer 3. It receives a block and converts it into a variable length coded signal. The multiplexer 11 receives a variable length coded signal from the variable length coder 8 and a variable length from the side information encoder 9. It receives the encoded shape information signal and serves to multiplex the two signals and transmit them to the transmission medium 12.

The first inverse quantizer 4 receives the quantized transform coefficient block from the quantizer 3 and converts the dequantized transform coefficient block into the inverse quantized transform coefficient block. The orthogonal conversion means by receiving the inverse quantized transform coefficient block from the first inverse quantizer 4 and using shape information input from the additional information encoder 9 and a mode control signal input from the mode controller 100. Inversely performing the inverse process with the (200) serves to output the corresponding inverse transform coefficients.

The adder 6a receives an inverse transform coefficient from the first inverse orthogonal transform means 300 and receives a previously restored image signal block stored in the first memory 7 and adds the two signals. The first memory 7 receives the reconstructed image signal block from the adder 6a and stores the reconstructed image signal block in the subtractor 1 for the next prediction. It plays a role of outputting.

The decoding apparatus according to the first embodiment of the present invention will be described with reference to FIG. 4 as follows.

The decoding apparatus according to the first embodiment of the present invention includes a demux 13, a decoder 15, a second inverse quantizer 16, an additional information decoder 14, a mode controller 400, and a second inverse orthogonality. The conversion means 500, the adder 6b, and the 2nd memory 18 are comprised.

The demux unit 13 decodes the encoded signal through the transmission medium 12 in the encoding apparatus and outputs the encoded shape information and the encoded image signal, and the decoder 15. The demux 13 receives a video signal encoded by the demux 13 and converts the signal into a variable length decoded signal.

The second inverse quantizer 16 receives a variable length decoded signal from the decoder 15 and converts the dequantized transform coefficient block into an inverse quantized transform coefficient block. The additional information decoder 14 is the demux unit 13. ) Receives the encoded shape information and restores the shape information.

The mode controller 400 receives the shape information restored by the additional information decoder 14 and generates a mode control signal in the same manner as the mode controller 100 of the encoding apparatus.

The second inverse orthogonal transform means 500 receives the inverse quantized transform coefficient block from the second inverse quantizer 16 and receives the orthogonal transform means 200 by the mode control signal input from the mode controller 400. It performs the inverse transformation in reverse to the conversion order and outputs the inverse transformation coefficient.

The adder 6b receives a signal block inversely transformed by the second inverse orthogonal conversion means 500 and receives an image signal block reconstructed in the second memory 18 and adds the two signals to restore the image. The second memory 18 stores the reconstructed input image signal block for prediction, and the signal block is output to the adder 6b for the next prediction.

An encoding method and a decoding method using a digital image compression encoding and decoding apparatus using shape adaptive selection according to the first embodiment of the present invention having the above-described configuration will be described.

First, the encoding method will be described. The video signal block is input to the subtractor 1, and the shape information is input to the additional information encoder 9 and encoded.

At this time, the subtractor 1 subtracts the input video signal block and the reconstructed video signal block output from the first memory 7 to obtain a prediction error signal block, and outputs the signal to the orthogonal transformation means 200.

Subsequently, the orthogonal transformation means 200 receives the prediction error signal block from the subtractor 1, performs orthogonal transformation according to the order determined by the mode control signal input from the mode controller 100, and the corresponding transformation coefficient. Outputs

Meanwhile, the process of generating a mode control signal in the mode controller 100 is omitted in the encoding apparatus.

In this case, the quantizer 3 converts the transform coefficient output from the orthogonal transform means 200 into a quantized transform coefficient block, and the variable length encoder 8 converts the transform coefficient block quantized by the quantizer 3. A variable length coded transform coefficient signal is received and the multiplexer 11 receives the variable length coded transform coefficient signal and receives the variable length coded shape information signal from the additional information encoder 9. The two signals are multiplexed and transmitted through the transmission medium 12.

On the other hand, the quantized transform coefficient block output from the quantizer 3 is input to the first inverse quantizer 4 is converted into a dequantized transform coefficient block, the first inverse orthogonal transform means 300 is the first 1 The inverse transform mode is controlled by a mode control signal input from the mode controller 100 by receiving the inverse quantized transform coefficient block from the inverse quantizer 4, thereby performing inverse of the orthogonal transform performed by the orthogonal transform means 200. Inverse orthogonal transformation is used to output the inverse transformation coefficient.

Subsequently, the adder 6a receives an inverse transform coefficient from the first inverse orthogonal transformation means 300 and simultaneously receives an image signal block restored in the first memory 7, adds the two signals, and restores the image signal block. The video signal block is stored in the first memory 7 and reconstructed by the subtractor 1.

Meanwhile, referring to the decoding method according to the first embodiment, first, the demux unit 13 receives the encoded video signal through the transmission medium 12 and demultiplexes the shape information and the variable length coded shape information. A length-coded transform coefficient signal is output, and the decoder 15 receives the variable length coded image signal and converts it into a quantized transform coefficient signal, while the side information decoder 14 converts the variable length coded shape information. Receive the input and restore the original shape information.

At this time, the second inverse quantizer 16 receives the transform coefficient signal quantized by the decoder 15 and converts the inverse quantized transform coefficient block, and the second inverse orthogonal transformation means 500 performs the second inverse quantization. The inverse transform mode is controlled by the mode control signal input from the mode controller 400 by receiving the inverse quantized transform coefficient block from the controller 16, and is inversely orthogonal to the orthogonal transform order in the orthogonal transform means 200. Outputs the inverse orthogonal transformed signal block by performing the conversion.

Subsequently, the adder 6b receives a signal block inversely orthogonally transformed by the second inverse orthogonal transformation means 500 and an image signal block previously restored in the second memory 18, and adds the two signals to be restored. Outputs a video signal block.

Meanwhile, the second memory 18 receives and stores the reconstructed video signal block output from the second adder 6b and outputs the reconstructed video signal block to the second adder 6b.

An encoding apparatus according to a second embodiment of the present invention will be described with reference to FIG. 4.

A coding apparatus according to a second embodiment of the present invention includes a subtractor 1, an additional information encoder 9, a mode controller 100 ', an orthogonal transform means 200', a quantizer 3, and a variable length encoder 8 ), A multiplexer (11), a first inverse quantizer (4), a first inverse orthogonal conversion means (300 '), an adder (6a), and a first memory (7), and the mode controller (100'). Since all components except for the orthogonal transformation means 200 'and the first inverse orthogonal transformation means 300' are the same as those of the first embodiment, a description of the same components will be omitted.

The mode controller 100 ′ will be described with reference to FIG. 7.

As shown in FIG. 7, the mode controller 100 ′ includes a boundary pixel measuring unit 140 and a comparator 150.

The boundary pixel measuring unit 140 outputs the pixel number information in the shape information of four directions of shape information of the block to be currently encoded, that is, left, right, top, and bottom of the block, and the comparator 150 ) Is a mode control signal for controlling the conversion and inverse conversion operations of the orthogonal transformation means 200 ′ and the first inverse orthogonal transformation means 300 ′ by comparing the pixel number information input from the boundary pixel measurement means 140. Outputs the role.

The mode controller 100 ′ outputs four different conversion mode control signals according to the position and size of the shape information. In general, when dividing an image block into an object and a non-object using shape information, the brightness value between pixels corresponding to the boundary surface tends to be darker than the brightness value inside the object. In the case of encoding, transformation may be performed in units of pixels having a higher similarity. In the case of the transcoheran coding, the higher the similarity between the pixels, the higher the coding efficiency. Therefore, when the orthogonal transformation is performed using the boundary pixels of the shape information, higher coding efficiency can be expected.

Referring to the operation of the mode controller 100 ′, first, the boundary pixel measuring unit 140 receives shape information of a block to be currently encoded by the side information encoder 9, and then determines left, right, up, and down of the block. The number of pixels in the shape information located on the side is output.

Subsequently, the comparator 130 compares the number of four types of pixels output from the boundary pixel measuring means 140 to output an appropriate mode control signal for the surface having the largest number of pixels.

In this case, the comparator 150 uses the mode control signal 1 when the most pixels exist at the bottom of the block, the mode control signal 2 when the most pixels exist at the right end of the block, and the most pixels at the top of the block. It is assumed that the mode control signal 3 is outputted when the most pixels exist in the left end of the block, which will be described in more detail.

8A to 8D are diagrams for explaining an orthogonal transformation operation according to a mode control signal of an image signal block input to the mode controller according to the second embodiment, wherein the hatched portions are the object portions to be encoded, and the dark hatched portions thereof. The part represents the boundary pixel of the input block.

Referring to FIG. 8A, a block represents an input image block, and the mode control signal 1 is output as the case where the most pixels exist on the bottom surface among the four surfaces of the block, and the orthogonal conversion means 200 ' ) Receives the mode control signal 1 from the mode controller 100 ′ and accordingly arranges the pixels of the input image block corresponding to the boundary of the shape information at the top as shown in block b of FIG. 8A. Subsequently, after shifting in the horizontal direction, the left end of the block is aligned as shown in block c of FIG. 8A, and then orthogonally transformed in the horizontal direction, and then perpendicular to the vertical direction as shown in block d of FIG. 8A. Perform the conversion.

Referring to FIG. 8B, a block of four blocks represents an input image block, and the mode control signal 2 is outputted as orthogonal transformation when most pixels are present on the rightmost side of the four surfaces of the block. The means 200 'receives the mode control signal 2 from the mode controller 100' and accordingly arranges the pixels of the input image block corresponding to the boundary of the shape information at the left end as shown in the block b of FIG. 8B. do. Subsequently, after shifting in the upper direction to align the upper column of the block as shown in block c of FIG. 8B and performing orthogonal transformation in the vertical direction, orthogonal transform in the horizontal direction as shown in block d in FIG. 8B. Do this.

Referring to FIG. 8C, a block represents an input image block, and the mode control signal 3 is output as the case where the largest number of pixels exist on the top surface among the four surfaces of the block. ) Receives the mode control signal 3 from the mode controller 100 ′ and symmetrically shifts the input video signal in the vertical direction as shown in block b of FIG. 8c, and moves to the top of the block as shown in block c. Sort it. Then, the left end of the block is aligned with the d block, and then the orthogonal transformation is performed in the horizontal direction, and then the orthogonal transformation is performed as shown in the e block.

Referring to FIG. 8D, a block represents an input image block, and the mode control signal 4 is outputted as the case where the most pixels exist on the left side of the four surfaces of the block, and the orthogonal conversion means 200 ') Receives the mode control signal 4 from the mode controller 100' and accordingly shifts the input video signal horizontally as shown in block b of FIG. 8D. Sort by columns. Then, the alignment is performed with respect to the upper end of the block as in block d, and then orthogonal in the vertical direction, and then orthogonal in the horizontal direction as shown in e block.

As described above, the orthogonal conversion means 200 'moves the image signal blocks inputted according to the mode control signals 1 to 4 input from the mode controller 100' to the upper and left ends, and then transforms the horizontal and vertical orthogonal transforms. After moving to the left and top ends, vertical and horizontal orthogonal transformation, or after vertical symmetry, move to the top and left end, and then to the horizontal and vertical orthogonal transformation, or after horizontal symmetry, and moving to left and top It acts as a vertical and horizontal orthogonal transformation.

The first inverse orthogonal transformation means 300 ′ operates as an inverse process of the conversion process in the orthogonal transformation means 200 ′. That is, when the mode control signal 1 is input, the inverse transformation is performed in the vertical direction and the inverse transformation is performed in the horizontal direction. After that, the signal blocks aligned with the top of the block are obtained by using the shape information, and then they are rearranged to the position of the original video signal by using the shape information.

In addition, when the mode control signal 2 is input, the inverse transformation is performed in the horizontal direction, and the inverse transformation is performed in the vertical direction, and the position information is rearranged using the shape information.

In addition, when the mode control signal 3 is input, the inverse transformation is performed in the vertical direction, and the inverse transformation is performed in the horizontal direction, and the shape information is used to rearrange the position of the original video signal.

In addition, when the mode control signal 4 is input, the inverse transformation is performed in the horizontal direction, and the inverse transformation is performed in the vertical direction, and the position information is rearranged using the shape information.

Next, a decoding apparatus according to a second embodiment of the present invention will be described with reference to FIG.

The decoding apparatus according to the second embodiment of the present invention includes a demux 13, a decoder 15, a second inverse quantizer 16, an additional information decoder 14, a mode controller 400 ', and a second station. Orthogonal conversion means 500 ', adder 6b, second memory 18, and all components except for the mode controller 400' and the second inverse orthogonal conversion means 500 ' Since it is the same as the embodiment, a description thereof will be omitted.

The mode controller 400 'receives the shape information restored by the additional information decoder 14 and outputs a mode control signal by the same process as that of the mode controller 100' of the encoding apparatus according to the second embodiment. The second inverse orthogonal transformation means 500 'receives the inverse quantization coefficient from the second inverse quantizer 16 and performs orthogonal transformation according to the mode control signals 1 to 4 input from the mode controller 400'. After performing the inverse orthogonal transformation with the means 200 'and outputting the inverse orthogonal transformation coefficient corresponding thereto, the detailed process thereof is the same as that of the first inverse orthogonal transformation means 300', and thus will be omitted. Shall be.

An encoding method and a decoding method using a digital image compression encoding and decoding apparatus using shape adaptive selection according to the second embodiment of the present invention having the above-described configuration will be described.

First, the encoding method will be described. The video signal block is input to the subtractor 1, and the shape information is input to the additional information encoder 9 and encoded.

At this time, the subtractor 1 subtracts the input image signal block and the reconstructed image signal block output from the first memory 7 to obtain a prediction error signal block, and outputs the signal to the orthogonal transformation means 200 '.

Subsequently, the orthogonal transformation means 200 ′ receives the prediction error signal block from the subtractor 1 and performs conversion by one mode control signal among the mode control signals 1 to 4 input from the mode controller 100 ′. The detailed description thereof will be omitted since it is published in the encoding apparatus according to the second embodiment.

In this case, the quantizer 3 converts the transform coefficient output from the orthogonal transform means 200 'into a quantized transform coefficient block, and the variable length encoder 8 converts the transform coefficient block quantized by the quantizer 3 Converts the signal into a variable length coded transform coefficient signal, and the multiplexer 11 receives the variable length coded transform coefficient signal and simultaneously receives the variable length coded shape information signal from the additional information encoder 9. The two signals are multiplexed and transmitted through the transmission medium 12.

On the other hand, the quantized transform coefficient block output from the quantizer 3 is input to the first inverse quantizer 4 is converted into a dequantized transform coefficient block, the first inverse orthogonal transform means 300 ' The inverse transform mode is controlled by any one of the mode control signals 1 to 4 inputted from the mode controller 100 'by receiving the inverse quantized transform coefficient block from the first inverse quantizer 4, thereby performing the quadrature conversion means ( The inverse transform coefficient is outputted by performing inverse orthogonal transformation as the inverse of the orthogonal transformation performed at 200 ').

Subsequently, the adder 6a receives an inverse transform coefficient from the first inverse orthogonal transformation means 300 'and simultaneously receives an image signal block reconstructed from the first memory 7 and adds the two signals to the image signal block. The video signal block is restored and stored in the first memory 7, and is restored to the subtractor 1.

Meanwhile, referring to the decoding method according to the second embodiment, first, the demux unit 13 receives the encoded video signal through the transmission medium 12 and demultiplexes the shape information and the variable length coded shape information. A length-coded transform coefficient signal is output, and the decoder 15 receives the variable length coded image signal and converts it into a quantized transform coefficient signal, while the side information decoder 14 converts the variable length coded shape information. Receive the input and restore the original shape information.

In this case, the second inverse quantizer 16 receives the transform coefficient signal quantized by the decoder 15 and converts the inverse quantized transform coefficient block, and the second inverse orthogonal transform means 500 'is the second inverse. The inverse transform mode is controlled by the mode control signal inputted from the mode controller 400 'by receiving the inverse quantized transform coefficient block from the quantizer 16 to reverse the orthogonal transform order in the orthogonal transform means 200'. Inverse orthogonal transformation is performed, and a detailed process thereof is the same as that of the first inverse orthogonal transformation means 300 ', and thus will be omitted.

Subsequently, the adder 6b receives the signal block that has been inversely orthogonally transformed by the second inverse orthogonal transformation means 500 'and the image signal block that has been previously restored in the second memory 18, and adds the two signals to restore the inverse orthogonal transformation. Output the video signal block.

Meanwhile, the second memory 18 receives and stores the reconstructed video signal block output from the second adder 6b and outputs the reconstructed video signal block to the second adder 6b.

As described above, according to the present invention, a digital image compression encoding and decoding apparatus using shape adaptive selection and a method thereof include a plurality of pixels in a video signal block using shape information of an image signal block to be encoded. First of all, the encoding efficiency can be increased by performing the transformation in the remaining direction, and the decoding efficiency is improved by performing the inverse transformation in the reverse order of the transformation by using the shape information reconstructed in the process of receiving and decoding the encoded signal. There is an excellent effect that you can increase.

Claims (30)

In an apparatus for compressing and encoding a video signal block by performing orthogonal transformation using shape information, A mode controller which receives shape information of an image signal block to be encoded and analyzes the number of pixels in the horizontal and vertical directions and outputs a mode control signal for performing orthogonal transformation in a direction having more pixels; And an orthogonal transformation means for receiving a mode control signal from the mode controller and performing orthogonal transformation according to the mode control signal. The method of claim 1, The mode controller outputs a mode control signal for performing orthogonal transformation first in a direction having a larger value among the maximum horizontal pixels and the maximum vertical pixels of the shape information input. Digital video compression encoding device. The method of claim 1, The mode controller outputs a mode control signal for dividing the total number of pixels in the shape information input into the maximum number of horizontal pixels and the maximum number of vertical pixels, respectively, to perform orthogonal transformation first in a direction having a larger value among the result values. Digital image compression encoding device using a shape adaptive selection characterized in that. The method according to any one of claims 1 to 3, The mode controller includes a horizontal counter for counting the number of horizontal pixels of the shape information inputted; A vertical counter that counts the number of vertical pixels of shape information input; And a comparator configured to output a mode control signal for first performing orthogonal transformation in a direction having a larger number of pixels by receiving and comparing information on the number of horizontal and vertical pixel counters in the horizontal and vertical counters. Digital video compression encoding apparatus using shape adaptive selection. A subtractor for outputting a prediction error signal block by subtracting a video signal block to be encoded and a reconstructed video signal block; An additional information encoder for outputting the reconstructed shape information and the variable length coded shape information to help the encoding; Receiving the reconstructed shape information of the image signal block to be encoded by the additional information encoder, analyzing the number of pixels in the horizontal and vertical directions, and outputting a mode control signal to first perform orthogonal transformation in a direction having more pixels Mode controller, Orthogonal transformation means for receiving a prediction error signal block from the subtractor and outputting a corresponding transformation coefficient by performing orthogonal transformation using the mode control signal input from the mode controller and the restored shape information input from the additional information encoder. and, A quantizer for receiving a transform coefficient from the orthogonal transform means and converting the transform coefficient into a quantized transform coefficient; A variable length encoder for receiving a quantized transform coefficient from the quantizer and converting the transform coefficient into a variable length coded signal; A shape adaptation device comprising: a multiplexer receiving a variable length coded signal from the variable length encoder and a variable length coded shape information signal from the side information encoder to multiplex the two signals and transmit the same to a transmission medium; Video compression encoding apparatus using automatic selection. The method of claim 5, An inverse quantizer for receiving a quantized transform coefficient from the quantizer and converting the quantized transform coefficient into a dequantized transform coefficient; By receiving the inverse quantized conversion coefficient from the inverse quantizer by using the recovered shape information input from the additional information encoder and the mode control signal input from the mode controller by performing the inverse conversion with the orthogonal transformation means Inverse orthogonal transform means for outputting a corresponding inverse transform coefficient; An adder for receiving an inverse transform coefficient from the inverse orthogonal transform means and receiving a previously restored video signal block and adding the two signals to restore the video signal block; And a memory for receiving the reconstructed image signal block by the adder, storing the image signal block for the next prediction, and outputting the reconstructed image signal block to the subtractor. . In a method of compressing and encoding a video signal block by receiving orthogonal transformation using shape information, Mode control signal that receives the shape information of the image signal block to be encoded and analyzes the number of pixels in the horizontal and vertical directions to perform orthogonal transformation first in the direction having the larger value among the maximum horizontal pixels and the maximum vertical pixels. Generating a mode control signal, and And an orthogonal transformation step of performing orthogonal transformation by the mode control signal outputted in the mode control signal generation step. In a method of compressing and encoding a video signal block by receiving orthogonal transformation using shape information, A mode that receives the shape information of the image signal block to be encoded and divides the total number of pixels in the shape information into the maximum horizontal pixels and the maximum vertical pixels, respectively, and performs orthogonal transformation in the direction having the larger value first. A mode control signal generation step of outputting a control signal; And an orthogonal transformation step of performing orthogonal transformation by the mode control signal outputted in the mode control signal generation step. An apparatus for decoding orthogonal transformed and compressed coded information, A mode controller which receives the restored shape information of the image block to be decoded and outputs a mode control signal for determining the number of pixels in the horizontal and vertical directions and first performing inverse orthogonal transformation in a direction having a smaller number of pixels; And an inverse orthogonal transformation means for receiving a mode control signal from the mode controller and performing inverse orthogonal transformation accordingly. The method of claim 9, The mode controller outputs a mode control signal for first performing inverse orthogonal transformation in a direction having a smaller value among the maximum horizontal pixels and the maximum vertical pixels of the shape information input. Digital video compression decoding device to use. The method of claim 9, The mode controller outputs a mode control signal for dividing the total number of pixels in the shape information input into the maximum horizontal pixel number and the maximum vertical pixel number respectively so as to first perform inverse orthogonal transformation in a direction having a smaller value among the result values. Digital image compression and decoding apparatus using shape adaptive selection characterized in that. The method according to any one of claims 9 to 11, The mode controller includes a horizontal counter for counting the number of horizontal pixels of the shape information inputted; A vertical counter that counts the number of vertical pixels of shape information input; And a comparator configured to output a mode control signal for first performing inverse orthogonal transformation in a direction having a smaller number of pixels by receiving and comparing information about the number of horizontal and vertical pixel counters in the horizontal and vertical counters. Digital image compression and decoding device using shape adaptive selection. A demux unit for receiving the encoded signal by the image compression encoding apparatus and demultiplexing the encoded shape information and outputting the encoded image signal; A decoder which receives the video signal encoded by the demux unit and converts the image signal into a variable length decoded signal; An inverse quantizer for receiving a variable length decoded signal from the decoder and converting the signal into a dequantized transform coefficient; An additional information decoder for receiving and restoring the shape information encoded by the demux unit; The additional information decoder receives the restored shape information of the image block to be currently decoded, and outputs a mode control signal for determining the number of pixels in the horizontal and vertical directions and first performing inverse orthogonal transformation in the direction having the smaller number of pixels. With a mode controller Inverse orthogonal transform means for receiving an inverse quantized transform coefficient from the inverse quantizer and performing inverse orthogonal transform by a mode control signal input from the mode controller; An adder for receiving a signal block that has been inversely orthogonally transformed by the inverse orthogonal transformation means and receiving a previously restored image signal block and adding the two signals to output the reconstructed image signal block; And a memory for receiving and storing the image signal block reconstructed by the adder and outputting the image signal block to the adder for the next prediction. In a method of decoding orthogonal transformed compressed coded information, Receives the shape information of the image block to be decoded and analyzes the number of pixels in the horizontal and vertical directions to inversely orthogonally transform the direction of the direction having the smaller value among the maximum horizontal pixels and the maximum vertical pixels. A mode control signal generating step of outputting a mode control signal; And an inverse orthogonal transformation step of performing inverse orthogonal transformation according to the mode control signal outputted in the mode control signal generating step. In a method of decoding orthogonal transformed compressed coded information, The restored shape information of the image block to be decoded is inputted, and the total number of pixels in the shape information is divided into the maximum horizontal pixels and the maximum vertical pixels, respectively. A mode control signal generating step of outputting a mode control signal for performing; And an inverse orthogonal transformation step of performing inverse orthogonal transformation according to the mode control signal outputted in the mode control signal generating step. In an apparatus for compressing and encoding a video signal block by performing orthogonal transformation using shape information, A mode controller which receives shape information of an image signal block to be encoded, compares the number of pixels of four edges of the image signal block, determines a conversion method, and outputs any one of mode control signals 1 to 4 corresponding thereto; And an orthogonal transformation means for receiving a mode control signal from the mode controller and aligning or symmetrically shifting the input image signal block and orthogonally transforming the image signal block. The method of claim 16, The mode controller outputs a mode control signal 1 when there are most pixels on the bottom surface of the four edges of the input image signal block. Accordingly, the orthogonal conversion means receives the mode control signal 1 to receive the shape information. Digitally using shape adaptive selection, wherein pixels of an input image signal block corresponding to a boundary are arranged at the top, shifted horizontally to be aligned with the left column of the block, and horizontal and vertical orthogonal transformations are sequentially performed. Image compression encoding device. The method of claim 16, The mode controller outputs a mode control signal 2 when there are the most pixels on the surface located at the right end of the four edges of the input image signal block. Accordingly, the orthogonal conversion means receives the mode control signal 2 and receives shape information. The pixels of the input image signal block corresponding to the edges of the input image signal block are arranged at the left end, shifted to the top to align with the top column of the block, and then vertically and horizontally orthogonal transformation is performed. Image compression encoding device. The method of claim 16, The mode controller outputs a mode control signal 3 when there are the most pixels on the top surface of the four edges of the input image signal block. Accordingly, the quadrature conversion means receives the mode control signal 3 and receives the input image signal. Digital image compression encoding apparatus using shape adaptive selection, characterized in that the pixels of the block are vertically symmetrically shifted, aligned at the top of the block, aligned with respect to the left end of the block, and then horizontally and vertically orthogonally transformed. . The method of claim 16, The mode controller outputs a mode control signal 4 when there are the most pixels on the left side of the four edges of the input image signal block. Accordingly, the quadrature conversion means receives the mode control signal 4 and receives an input image. Digital image compression encoding using shape adaptive selection, characterized in that the pixels of the signal block are symmetrically moved in the horizontal direction, aligned to the left end of the block, aligned to the top of the block, and then vertical and horizontal orthogonal transformation is performed in order. Device. The method according to any one of claims 16 to 20, The mode controller includes boundary pixel measurement means for receiving shape information of an image signal block to be encoded and outputting information on the number of pixels of four edges of the image signal block; And a comparator for receiving and comparing information on the number of pixels of four edges of the input image signal block from the boundary pixel measuring means and outputting any one of mode control signals 1 to 4 for the plane having the largest number of pixels. Digital video compression encoding apparatus using shape adaptive selection. A subtractor for outputting a prediction error signal block by subtracting a video signal block to be encoded and a reconstructed video signal block; An additional information encoder for outputting the reconstructed shape information and the variable length coded shape information to help the encoding; The sub information encoder receives the restored shape information of the image signal block to be encoded, compares the number of pixels of four edges of the image signal block, determines a conversion method, and outputs any one of mode control signals 1 to 4 corresponding thereto. Mode controller, Orthogonal transformation means for receiving a mode control signal from the mode controller and aligning or symmetrically shifting the prediction error signal block inputted from the subtractor according to the orthogonal transformation; A quantizer for receiving a transform coefficient from the orthogonal transform means and converting the transform coefficient into a quantized transform coefficient; A variable length encoder for receiving a quantized transform coefficient from the quantizer and converting the transform coefficient into a variable length coded signal; A shape adaptation device comprising: a multiplexer receiving a variable length coded signal from the variable length encoder and a variable length coded shape information signal from the side information encoder to multiplex the two signals and transmit the same to a transmission medium; Video compression encoding apparatus using automatic selection. The method of claim 22, An inverse quantizer for receiving a quantized transform coefficient from the quantizer and converting the quantized transform coefficient into a dequantized transform coefficient; Inverse transformation is performed inversely with the orthogonal transformation means by receiving the inverse quantized transform coefficient from the inverse quantizer and using the restored shape information inputted from the side information encoder and a mode control signal inputted from the mode controller. And inverse orthogonal transform means for outputting an inverse transform coefficient corresponding to the position of the original video signal block by using the shape information. An adder for receiving an inverse transform coefficient from the inverse orthogonal transform means and receiving a previously restored video signal block and adding the two signals to restore the video signal block; And a memory for receiving the reconstructed image signal block by the adder, storing the image signal block for the next prediction, and outputting the reconstructed image signal block to the subtractor. . In a method of compressing and encoding a video signal block by receiving orthogonal transformation using shape information, A mode control signal generation step of receiving shape information of an image signal block to be encoded and comparing the number of pixels of four edges of the image signal block and outputting any one of mode control signals 1 to 4 corresponding thereto; In the mode control signal generation step, when the mode control signal 1 is output because the most pixels exist on the lower surface among the four edges of the image signal block inputted, the pixels of the input image signal block corresponding to the boundary of the shape information are accordingly. And a first conversion step of arranging at the top, shifting in the horizontal direction to align with the left column of the block, and performing horizontal and vertical orthogonal transformations in order. The method of claim 24, When the mode control signal 2 is output due to the largest number of pixels on the surface located at the right end of the four edges of the image signal block input in the mode control signal generation step, according to the boundary of the shape information, Digital image compression encoding using shape adaptive selection, comprising a second conversion step of placing pixels at the left end, shifting them to the top, aligning them in the top column of the block, and performing vertical and horizontal orthogonal transformations in order. Way. The method of claim 24, When the mode control signal 3 is output because most pixels exist on the top surface of the four edges of the image signal block input in the mode control signal generation step, the pixels of the input image signal block are symmetrically moved in the vertical direction. And a third transformation step of aligning the upper end of the block, aligning the left end of the block, and then performing horizontal and vertical orthogonal transformations in order. The method of claim 24, When the mode control signal 4 is output due to the largest number of pixels on the left side of the four edges of the image signal block input in the mode control signal generation step, the pixels of the input image signal block are symmetrical in the horizontal direction. And a fourth transforming step of moving the blocks, arranging them to the left end of the block, and aligning the upper ends of the blocks, and performing vertical and horizontal orthogonal transformations in order. An apparatus for decoding orthogonal transformed and compressed coded information, A mode controller which receives the reconstructed shape information of the image block to be currently decoded, compares the number of pixels of four edges of the image signal block, determines an inverse conversion method, and outputs a mode control signal accordingly; The mode controller receives the mode control signal and correspondingly performs an inverse orthogonal transformation inverse to the orthogonal transformation process and then inverts the orthogonal transformation means to rearrange the position of the original video signal. Digital video compression decoding device. A demux unit for receiving the encoded signal by the image compression encoding apparatus and demultiplexing the encoded shape information and outputting the encoded image signal; A decoder which receives the video signal encoded by the demux unit and converts the image signal into a variable length decoded signal; An inverse quantizer for receiving a variable length decoded signal from the decoder and converting the signal into a dequantized transform coefficient; An additional information decoder for receiving and restoring the shape information encoded by the demux unit; A mode controller which receives the reconstructed shape information of the image block to be decoded by the additional information decoder, compares the number of pixels of four edges of the image signal block, and determines an inverse conversion method and outputs a mode control signal accordingly; An inverse orthogonal transformation in which a mode control signal is inputted from the mode controller and inversely orthogonally transforms an inverse quantized transformation coefficient inputted from the inverse quantizer into an orthogonal transformation process and inversely to a position of an original video signal Sudan, An adder for receiving a signal block that has been inversely orthogonally transformed by the inverse orthogonal transformation means and receiving a previously restored image signal block and adding the two signals to output the reconstructed image signal block; And a memory for receiving and storing the image signal block reconstructed by the adder and outputting the image signal block to the adder for the next prediction. In a method of decoding orthogonal transformed compressed coded information, A mode control signal generation step of receiving the reconstructed shape information of the current image block to be decoded, comparing the number of pixels of four edges of the image signal block to determine an inverse conversion method, and outputting a mode control signal accordingly; In the mode control signal generation step receives the mode control signal corresponding to the orthogonal conversion process and inverse orthogonal transform inversely corresponding to the shape of the original image signal, the inverse transform step consisting of the step of adaptive selection Digital video compression decoding method to use.