Method and apparatus for encoding interlaced 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 (c1) 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 (c1) has the steps of:
 (c11) row-padding said at least one undefined texture pixel on a row-by-row basis to generate a padded row; and 
 (c12) 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:
 (f1) 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 
 (f2) 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 (c1). 
     
     
       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 padding apparatus for padding a top or bottom field block based on shape information for the current VOP, to store the padded field block, the top or bottom field block comprising undefined texture pixels and defined texture pixels, the padding apparatus comprising:
 a texture pixel padding circuit configured to extrapolate the undefined texture pixels based on the defined texture pixels to generate an extrapolated boundary block for the top or the bottom field block;   a transparent field padding circuit configured to pad an undefined field block of the extrapolated boundary block based on the other field block thereof, wherein the undefined field block represents a field block comprising the undefined texture pixels only;   an adjacent block padding circuit configured to expand 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 configured to pad 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 padding apparatus further comprises:
 a horizontal padding circuit configured to pad the undefined texture pixel in a row of the macroblock of interlaced VOP based on one or more of the defined texture pixels in said row, 
 a transparent row padding circuit configured to pad the transparent row from at least one nearest padded row, wherein the transparent row represents a row having the defined texture pixels only, 
 a vertical padding circuit configured to pad the undefined texture pixel in a row having only the undefined texture pixels based on one or more of the defined texture pixels in another one or more rows comprising at least one defined texture pixel in same field block, 
 an adjacent macroblock padding circuit configured to expand an undefined adjacent macroblock based on the padded boundary macroblock, wherein the undefined adjacent macroblock is adjacent to the padded boundary macroblock and comprises only undefined texture pixels, and 
 a remaining macroblock padding circuit configured to pad the exterior macroblock not adjacent to the padded boundary macroblock with a constant value. 
   
     
     
       16. The apparatus of claim 15, wherein the adjacent macroblock padding circuit includes:
 means for 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   means for replicating a vertical border or a horizontal border of the selected padded boundary macroblock rightwards, downwards, leftwards or upwards.   
     
     
       17. The apparatus of claim 15, wherein the constant value is 2 L−1 , wherein L is a number of bits assigned for each pixel. 
     
     
       18. The apparatus of claim 15, wherein the constant value is 128.