Method and apparatus for encoding a video signal

• US 6,310,916 B1
• Filed: 06/02/1998
• Issued: 10/30/2001
• Est. Priority Date: 03/14/1998
• Status: Expired due to Fees

• Current Assignee: ZTE Corporation
• Original Assignee: Daewoo Electronics Company Limited (Dayou Holdings Co.,Ltd.)
• Inventors: Han, Seok-Won
• Primary Examiner(s): Kelley, Chris
• Assistant Examiner(s): WONG, ALLEN C
• Application Number:
  US09/088,685
• Time in Patent Office: 1,246 Days
• Field of Search: 348/420, 348/403, 382/250, 382/243, 386/95, 375/240
• US Class Current: 375/240.11
• CPC Class Codes: H04N 19/112 according to a given display mode, e.g. for interlaced or progressive display mode
• CPC Class Codes: H04N 19/122 Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type
• CPC Class Codes: H04N 19/13 Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC]
• CPC Class Codes: H04N 19/146 Data rate or code amount at the encoder output
• CPC Class Codes: H04N 19/149 by estimating the code amount by means of a model, e.g. mathematical model or statistical model
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/18 the unit being a set of transform coefficients
• CPC Class Codes: H04N 19/20 using video object coding
• CPC Class Codes: H04N 19/30 using hierarchical techniques, e.g. scalability H04N19/63 takes precedence
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/60 using transform coding
• CPC Class Codes: H04N 19/91 Entropy coding, e.g. variable length coding [VLC] or arithmetic coding

Abstract

A video signal encoder codes a video signal including texture information and shape information on each of macroblocks, a macroblock having 16×16 pixels and being dividable into 4 number of equal-sized DCT-blocks. The encoder produces encoded shape information by encoding the shape information on a processing macroblock and generates a reconstructed shape information by decoding the encoded shape information. Then, a DCT_type of the processing macroblock is determined based on the reconstructed shape information and the texture information on the processing macroblock to thereby provide DCT_type information representing the DCT_type. Once the DCT_type of the processing macroblock is decided, the encoder generates encoded texture information by adaptively encoding the texture information through the use of a progressive or an interlaced coding technique in response to the DCT_type information. Furthermore, the encoder generates CBPY information by using the encoding results of the texture information and provides a data stream to be transmitted in sequence of the encoded shape information, the encoded CBPY information, the DCT_type information and the encoded texture information.

Claims

1. A method, for use in a video signal encoder, for coding texture information of a video signal which includes the texture information and shape information on each of macroblocks, each macroblock having M×

M pixels and being dividable into P number of equal-sized DCT-blocks, M and P being positive integers, respectively, comprising the steps of;

(a) determining a DCT_type of a target macroblock based on the shape information and the texture information on the target macroblock, wherein the DCT_type represents the more effective coding technique between a progressive and an interlaced coding techniques for encoding the texture information, the step (a) including the steps of;

(a11) determining a block type of the target macroblock based on the shape information, wherein the block type is determined as either an object or a boundary macroblock, the boundary macroblock including at least one background pixel located outside an object expressed by the video signal and at least one object pixel located inside the object, and the object macroblock containing only object pixels;

(a12) selecting the progressive coding type as the DCT_type of the target macroblock if the target macroblock is the boundary macroblock; and

(a13) deciding the DCT_type of the target macroblock by using the texture information if the target macroblock is determined as the object macroblock and providing DCT_type information representing the decided DCT_type;

(b) generating encoded texture information by adaptively encoding the texture information through the use of the progressive or the interlaced coding technique in response to the DCT_type, wherein the step (b) includes the steps of;

(b11) re-forming the texture information and the shape information in response to the DCT_type;

(b12) detecting one or more non-transparent DCT-blocks for the target macroblock based on the re-formed shape information, wherein each non-transparent DCT-block has a DCT-block size and contains at least one object pixel;

(b13) converting the re-formed texture information corresponding to each of the non-transparent DCT-blocks into a set of DCT coefficients;

(b14) quantizing the set of DCT coefficients to thereby produce a set of quantized DCT coefficients; and

(b15) producing the encoded texture information by encoding the sets of quantized DCT coefficients corresponding to all of the non-transparent DCT-blocks;

(c1) checking whether there exists at least one non-zero AC component in the set of quantized DCT coefficients corresponding to each of the non-transparent DCT-blocks;

(d1) producing CBPY information representing whether each of the sets of quantized DCT coefficients corresponding to the target macroblock contains at least one non-zero AC component therein in conformity with the results of the step (c1); and

(e1) providing encoded CBPY information by encoding the CBPY information.

2. The method of claim 1 further comprising the step of producing encoded shape information by encoding the shape information on the target macroblock.

3. The method of claim 2 further comprising the step of supplying a data stream to be transmitted which contains encoded information in sequence of the encoded shape information, the encoded CBPY information, the DCT_type information and the encoded texture information.

4. The method of claim 1 further comprising, prior to the step (a), the step of producing encoded shape information by encoding input shape data on the target macroblock and generating the shape information on the target macroblock by decoding the encoded shape information.

5. The method of claim 4 further comprising the step of supplying a data stream to be transmitted which contains encoded information in sequence of the encoded shape information, the encoded CBPY information, the DCT_type information and the encoded texture information.

6. A method, for use in a video signal encoder, for coding texture information of a video signal which includes the texture information and shape information on each of macroblocks, each macroblock having M×

M pixels and being dividable into P number of equal-sized DCT-blocks, M and P being positive integers, respectively, comprising the steps of;

(a) determining a DCT_type of a target macroblock based on the shape information and the texture information on the target macroblock, wherein the DCT_type represents the more effective coding technique between a progressive and an interlaced coding techniques for encoding the texture information, the step (a) including the steps of;

(a21) re-forming the shape information on the target macroblock into a progressive and an interlaced type macroblocks according to the progressive and the interlaced coding techniques, respectively;

(a22) calculating numbers of non-transparent DCT-blocks in the progressive and the interlaced type macroblocks, wherein each non-transparent DCT-block has a DCT-block size and contains at least one object pixel located inside an object expressed by the video signal; and

(a23) deciding the DCT_type of the target macroblock based on the texture information and the numbers of non-transparent DCT-blocks in the progressive and the interlaced type macroblocks, wherein the step (a23) contains the steps of;

(a231) comparing the numbers of non-transparent DCT-blocks in the progressive and the interlaced type macroblocks;

(a232) selecting a coding type corresponding to a smaller number as the DCT_type of the target macroblock if the numbers of non-transparent DCT-blocks in the progressive and the interlaced type macroblocks are different from each other; and

(a233) deciding the DCT_type of the target macroblock by using the texture information if the numbers of non-transparent DCT-blocks in the progressive and the interlaced type macroblocks are non-zero and identical to each other and providing DCT_type information representing the decided DCT_type;

(b) generating encoded texture information by adaptively encoding the texture information through the use of the progressive or the interlaced coding technique in response to the DCT_type, wherein the step (b) includes the steps of;

(b21) re-forming the texture information and the shape information in response to the DCT_type;

(b22) detecting one or more non-transparent DCT-blocks for the target macroblock based on the re-formed shape information;

(b23) converting the re-formed texture information corresponding to each of the non-transparent DCT-blocks into a set of DCT coefficients;

(b24) quantizing the set of DCT coefficients to thereby produce a set of quantized DCT coefficients; and

(b25) producing the encoded texture information by encoding the sets of quantized DCT coefficients corresponding to all of the non-transparent DCT-blocks;

(c2) checking whether there exists at least one non-zero AC component in the set of quantized DCT coefficients corresponding to each of the non-transparent DCT-blocks;

(d2) producing CBPY information representing whether each of the sets of quantized DCT coefficients corresponding to the target macroblock contains at least one non-zero AC component therein in conformity with the results of the step (c2); and

(e2) providing encoded CBPY information by encoding the CBPY information.

7. The method of claim 6 further comprising the step of producing encoded shape information by encoding the shape information on the target macroblock.

8. The method of claim 7 further comprising the step of supplying a data stream to be transmitted which contains encoded information in sequence of the encoded shape information, the encoded CBPY information, the DCT_type information and the encoded texture information.

9. The method of claim 6 further comprising, prior to the step (a), the step of producing encoded shape information by encoding input shape data on the target macroblock and generating the shape information on the target macroblock by decoding the encoded shape information.

10. The method of claim 9 further comprising the step of supplying a data stream to be transmitted which contains encoded information in sequence of the encoded shape information, the encoded CBPY information, the DCT_type information and the encoded texture information.

11. An apparatus for coding a video signal which includes texture information and shape information on each of macroblocks, a macroblock having M×

M pixels and being dividable into P number of equal-sized DCT-blocks, M and P being positive integers, respectively, comprising;

means for producing encoded shape information by encoding the shape information on a target macroblock and generating reconstructed shape information by decoding the encoded shape information;

means for determining a DCT_type of the target macroblock based on the reconstructed shape information and the texture information on the target macroblock and providing DCT_type information representing the DCT_type, wherein the DCT_type represents the more effective coding technique between a progressive and an interlaced coding techniques for encoding the texture information, the DCT_type determining means including;

means for determining a block type of the target macroblock based on the reconstructed shape information, wherein the block type is determined as either an object or a boundary macroblock, the boundary macroblock including at least one background pixel located outside an object expressed by the video signal and at least one object pixel located inside the object, and the object macroblock containing only object pixels, and providing a block indication signal representing the block type; and

means for deciding the DCT_type of the target macroblock in response to the block indication signal and providing the DCT_type information, wherein if the block indication signal represents the boundary macroblock, the DCT_type of the target macroblock becomes a progressive coding type and, if the block indication signal shows the object macroblock, the DCT_type deciding means determines the DCT_type of the target macroblock by using the texture information;

means for generating encoded texture information by adaptively encoding the texture information through the use of the progressive or the interlaced coding technique in response to the DCT_type information, wherein the encoded texture information generating means includes;

means for re-forming the texture information and the reconstructed shape information in response to the DCT_type;

means for detecting one or more non-transparent DCT-blocks for the target macroblock based on the re-formed shape information, wherein each non-transparent DCT-block has a DCT-block size and contains at least one object pixel;

means for converting the re-formed texture information corresponding to each of the non-transparent DCT-blocks into a set of DCT coefficients;

means for quantizing the set of DCT coefficients to thereby produce a set of quantized DCT coefficients; and

means for producing the encoded texture information by encoding the sets of quantized DCT coefficients corresponding to all of the non-transparent DCT-blocks;

means for checking whether there exists at least one non-zero AC component in the set of quantized DCT coefficients corresponding to each of the non-transparent DCT-blocks;

means for producing CBPY information representing whether each of the sets of quantized DCT coefficients corresponding to the target macroblock contains at least one non-zero AC component therein in conformity with the checking result; and

means for providing encoded CBPY information by encoding the CBPY information.

12. The apparatus as recited in claim 11 further comprising:

means for supplying a data stream to be transmitted which contains encoded information in sequence of the encoded shape information, the encoded CBPY information, the DCT_type information and the encoded texture information.

13. An apparatus for coding a video signal which includes texture information and shape information on each of macroblocks, a macroblock having M×

M pixels and being dividable into P number of equal-sized DCT-blocks, M and P being positive integers, respectively, comprising;

means for producing encoded shape information by encoding the shape information on a target macroblock and generating reconstructed shape information by decoding the encoded shape information;

means for determining a DCT_type of the target macroblock based on the reconstructed shape information and the texture information on the target macroblock and providing DCT_type information representing the DCT_type, wherein the DCT_type represents the more effective coding technique between a progressive and an interlaced coding techniques for encoding the texture information, the DCT_type determining means including;

means for re-forming the reconstructed shape information into a progressive and an interlaced type macroblocks according to the progressive and the interlaced coding techniques, respectively;

means for calculating the numbers of non-transparent DCT-blocks in the progressive and the interlaced type macroblocks, wherein each non-transparent DCT-block has a DCT-block size and contains at least one object pixel located inside an object expressed by the video signal; and

means for deciding the DCT_type of the target macroblock based on the texture information and the numbers of non-transparent DCT-blocks in the progressive and the interlaced type macroblocks, wherein the DCT_type deciding means contains;

means for comparing the numbers of non-transparent DCT-blocks in the progressive and the interlaced type macroblocks;

means for choosing a coding type corresponding to a smaller number as the DCT_type of the target macroblock if the numbers of non-transparent DCT-blocks in the progressive and the interlaced type macroblocks are different from each other; and

means for deciding the DCT_type of the target macroblock by using the texture information if the numbers of non-transparent DCT-blocks in the progressive and the interlaced type macroblocks are non-zero and identical to each other and providing DCT_type information representing the decided DCT_type;

means for generating encoded texture information by adaptively encoding the texture information through the use of the progressive or the interlaced coding technique in response to the DCT_type information, wherein the encoded texture information generating means includes;

means for re-forming the texture information and the reconstructed shape information in response to the DCT_type;

means for detecting one or more non-transparent DCT-blocks for the target macroblock based on the re-formed shape information;

means for converting the re-formed texture information corresponding to each of the non-transparent DCT-blocks into a set of DCT coefficients;

means for quantizing the set of DCT coefficients to thereby produce a set of quantized DCT coefficients; and

means for producing the encoded texture information by encoding the sets of quantized DCT coefficients corresponding to all of the non-transparent DCT-blocks;

means for checking whether there exists at least one non-zero AC component in the set of quantized DCT coefficients corresponding to each of the non-transparent DCT-blocks;

means for producing CBPY information representing whether each of the sets of quantized DCT coefficients corresponding to the target macroblock contains at least one non-zero AC component therein in conformity with the checking result; and

means for providing encoded CBPY information by encoding the CBPY information.

14. The apparatus as recited in claim 13 further comprising:

means for supplying a data stream to be transmitted which contains encoded information in sequence of the encoded shape information, the encoded CBPY information, the DCT_type information and the encoded texture information.