Method and apparatus for encoding interplaced macroblock texture information

Abstract

A method for padding interlaced texture information on a reference VOP to perform a motion estimation detects whether said each texture macroblock of the reference VOP is a boundary block or not. After the undefined texture pixels of the boundary block are extrapolated from the defined texture pixels thereof by using a horizontal repetitive padding, a transparent row padding and a transparent field padding sequentially, an undefined adjacent block is expanded based on the extrapolated boundary block.

1. A method for encoding interlaced texture information on a texture macroblock basis through a motion estimation between a current VOP and its one or more reference VOP's, wherein each texture macroblock of the current and the reference VOP's has M×N defined or undefined texture pixels, M and N being positive even integers, respectively, the method comprising the steps of:
 (a) detecting whether said each texture macroblock of each reference VOP is a boundary block or not, wherein the boundary block has at least one defined texture pixel and at least one undefined texture pixel;  
 (b) dividing the boundary block into two field blocks, each field block having M/2×N texture pixels;  
 (c) extrapolating the undefined texture pixels of each field block based on the defined texture pixels thereof to generate an extrapolated boundary block for said two field blocks;  
 (d) if the boundary block has an undefined field block and a defined field block, padding the undefined field block based on the defined field block, wherein the undefined field block and the defined field block represent one field block having the undefined texture pixels only and the other field block having at least one defined texture pixel, respectively; and  
 (f) expanding an undefined adjacent block based on the extrapolated boundary block, wherein the undefined adjacent block is adjacent to the extrapolated boundary block and has only undefined texture pixels,  
 wherein the step (c) further includes the step of (c 1 ) field-padding said at least one undefined texture pixel in a field block from said at least one defined texture pixel therein, to thereby generate a padded field block for the field block,  
 wherein the step (c 1 ) has the steps of: 
 (c 11 ) row-padding said at least one undefined texture pixel on a row-by-row basis to generate a padded row; and  
 (c 12 ) padding, if there exists a transparent row, the transparent row from at least one nearest padded row, wherein the transparent row represents a row having the undefined texture pixels only.  
 
 
     
     
       2. The method as recited in  claim 1 , wherein said step (f) includes the steps of:
 (f 1 ) selecting, if said undefined adjacent block is surrounded by a plurality of extrapolated boundary blocks, one of the left, the upper, the right and the below extrapolated boundary blocks of said undefined adjacent block in this priority; and  
 (f 2 ) replicating a vertical or a horizontal border of the selected extrapolated boundary block rightwards, downwards, leftwards or upwards, to thereby expand the undefined adjacent block, wherein the vertical or the horizontal border adjoins said undefined adjacent block.  
 
     
     
       3. The method as recited in  claim 1 , wherein all the undefined texture pixels of said undefined field block are padded with a constant value. 
     
     
       4. The method as recited in  claim 3 , wherein all the undefined texture pixels of said undefined field block are padded with a mean value of both the defined texture pixels and padded texture pixels within the padded field block for the other field block, wherein the padded texture pixels are field-padded through the step (c 1 ). 
     
     
       5. The method as recited in  claim 3 , wherein all the undefined texture pixels of said undefined field block are padded with a mean value of the defined texture pixels within the padded field block for the other field block. 
     
     
       6. The method as recited in  claim 3 , wherein the constant value is 2 L−1 , wherein L is the number of bits assigned for each pixel. 
     
     
       7. The method as recited in  claim 6 , wherein L is 8. 
     
     
       8. An apparatus for encoding interlaced texture information on a texture macroblock basis through a motion estimation between a current VOP and its one or more reference VOP's, wherein each texture macroblock of the current and reference VOP's has M×N texture pixels, M and N being positive even integers, respectively, the apparatus comprising:
 a boundary block detector for detecting whether said each texture macroblock of each reference VOP is a boundary block or not, wherein the boundary block has at least one defined texture pixel and at least one undefined texture pixel;  
 a field divider for dividing the boundary block into two field blocks, each field block having M/2×N texture pixels;  
 a texture pixel padding circuit for extrapolating the undefined texture pixels of each field block based on the defined texture pixels thereof to generate an extrapolated boundary block for said two field blocks;  
 a transparent field padding circuit for padding an undefined field block of the boundary block based on the other field block thereof, wherein the undefined field block represents a field block having the undefined texture pixels only;  
 an adjacent block padding circuit for expanding an undefined adjacent block based on the extrapolated boundary block, wherein the undefined adjacent block is adjacent to the extrapolated boundary block and has the undefined texture pixels only; and  
 a field-padding circuit for field-padding the undefined texture pixels in a field block from the defined texture pixels therein, to thereby generate a padded field block for the field block, wherein the field-padding circuit includes: 
 a horizontal padding circuit for padding the undefined texture pixels on a row-by-row basis to generate a padded row; and  
 a transparent row padding circuit for padding the transparent row from at least one nearest padded row, wherein the transparent row represents a row having the defined texture pixels only.  
 
 
     
     
       9. The apparatus as recited in  claim 8 , wherein said adjacent block padding circuit includes:
 a selector for selecting one of the left, the upper, the right and the below extrapolated boundary blocks of said undefined adjacent block in this priority; and  
 means for replicating a vertical or a horizontal border of the selected extrapolated boundary block rightwards, downwards, leftwards or upwards, to thereby expand the undefined adjacent block, wherein the vertical or the horizontal border adjoins said undefined adjacent block.  
 
     
     
       10. The apparatus as recited in  claim 8 , wherein all the undefined texture pixels of said undefined field block are padded with a constant value. 
     
     
       11. The apparatus as recited in  claim 10 , wherein all the undefined texture pixels of said undefined field block are padded with a mean value of both the defined texture pixels and padded texture pixels within the padded field block for the other field block, wherein the padded texture pixels are field-padded through the field-padding circuit. 
     
     
       12. The apparatus as recited in  claim 10 , wherein all the undefined texture pixels of said undefined field block are padded with a mean value of the defined texture pixels within the padded field block for the other field block. 
     
     
       13. The apparatus as recited in  claim 10 , wherein the constant value is 2 L−1 , L being the number of bits assigned for each pixel. 
     
     
       14. The apparatus as recited in  claim 13 , wherein L is 8. 
     
     
       15. A method for encoding interlaced texture information on a texture macroblock basis using a field prediction between a current VOP and its one or more reference VOP's, wherein the texture macroblock of the current VOP has M×N defined or undefined texture pixels, M and N being positive integers, respectively, the method comprising:
   providing top field block or bottom field block of the texture macroblock of the current VOP;        determining a motion vector and a predicted top or bottom field block for each current top or bottom field block on a field - by - field basis, wherein the motion vector denotes a displacement between each current top or bottom field block and the predicted top or bottom field block of the reference VOP;        obtaining an error field block by subtracting the predicted top or bottom field block from each current top or bottom field block on a corresponding pixel - by - pixel basis;        discrete - cosine - transforming the error field block on a DCT block - by - DCT block basis;        quantizing the DCT coefficients; and        performing a statistical encoding on the quantized DCT coefficients and motion vector, for each top or bottom field block,        wherein the reference VOP is obtained by padding the previous reconstructed texture information based on shape information,        wherein when the previous reconstructed texture information is a boundary macroblock of interlaced VOP,  ( i )  the undefined texture pixel in a row of the macroblock of interlaced VOP is padded based on one or more of the defined texture pixels in said row,  ( ii )  the undefined texture pixels in a row having only the undefined texture pixels are padded based on one or more of the defined texture pixels in another one or more rows having at least one defined texture pixel in same field block, and  ( iii )  the field block has only the undefined texture pixels is padded with a constant value.     
     
     
       16. The method of  claim 15 , wherein the constant value is  2   L−1   , wherein L is a number of bits assigned for each pixel.   
     
     
       17. The method of  claim 15 , wherein the constant value is  128 . 
     
     
       18. A method for encoding interlaced texture information on a texture macroblock basis using a field prediction between a current VOP and its one or more reference VOP's, wherein the texture macroblock of the current VOP has M×N defined or undefined texture pixels, M and N being positive integers, respectively, the method comprising:
   providing top field block or bottom field block of the texture macroblock of the current VOP;        determining a motion vector and a predicted top or bottom field block for each current top or bottom field block on a field - by - field basis, wherein the motion vector denotes a displacement between each current top or bottom field block and the predicted top or bottom field block of the reference VOP;        obtaining an error field block by subtracting the predicted top or bottom field block from each current top or bottom field block on a corresponding pixel - by - pixel basis;        discrete - cosine - transforming the error field block on a DCT block - by - DCT block basis;        quantizing the DCT coefficients;        performing a statistical encoding on the quantized DCT coefficients and motion vector, for each top or bottom field block;        performing an inverse quantization and inverse transform on the quantized DCT coefficients to obtain a reconstructed error field block;        combining the reconstructed error field block and the predicted top or bottom field block on a pixel - by - pixel basis; and        padding a reconstructed top or bottom field block based on shape information for the current VOP, to thereby store the padded top or bottom field blocks as reference interlaced texture information,        wherein the step of padding a reconstructed top or bottom field block further includes the substeps of:      padding the undefined texture pixel of the reconstructed boundary top or bottom field block based on one or more the defined texture pixels in same field block,        if the boundary top or bottom field block has only undefined texture pixels, padding the undefined texture pixels with middle value  2     L−1    of all the possible values for any texture pixel,        expanding an undefined adjacent macroblock based on the padded boundary macroblock, wherein the undefined adjacent macroblock is adjacent to the padded boundary macroblock and has only undefined texture pixels.       
     
     
       19. The method of  claim 18 , wherein the substep of padding the undefined texture pixel of the reconstructed boundary top or bottom field block includes the steps of;
   row - padding at least one undefined texture pixel on a row - by - row basis to generate a padded row, and        padding, if there exist one or more transparent rows, the transparent row based on at least one nearest padded row, wherein the transparent row has only the undefined textures.     
     
     
       20. The method of  claim 18 , wherein the substep of expanding an undefined adjacent macroblock based on the padded boundary macroblock includes the steps of;
   selecting, if said undefined adjacent block is surrounded by a plurality of padded boundary macroblocks, one of the left, the upper, the right and the below extrapolated boundary macroblocks of said undefined adjacent macroblock in this priority, and        replicating a vertical border or a horizontal border of the selected padded boundary macroblock rightwards, downwards, leftwards or upwards.     
     
     
       21. The method of  claim 18 , wherein middle value  2   L−1    of all the possible values for any texture pixel is  128 .