Region sizing for macroblocks
Coding techniques for a video image compression system involve improving an image quality of a sequence of two or more bi-directionally predicted intermediate frames, where each of the frames includes multiple pixels. One method involves determining a brightness value of at least one pixel of each bi-directionally predicted intermediate frame in the sequence as an equal average of brightness values of pixels in non-bidirectionally predicted frames bracketing the sequence of bi-directionally predicted intermediate frames. The brightness values of the pixels in at least one of the non-bidirectionally predicted frames is converted from a non-linear representation.
1. A method for video imaging, the method comprising:
determining, at a decoder, pixel values for a 16×16 macroblock, the 16×16 macroblock being partitioned into at least three regions, each of the at least three regions being adjacent to at least one of the other at least three regions;
receiving, at the decoder, at least one motion vector for each of the at least three regions,
wherein the at least three regions vary in block sizes,
wherein the at least three regions include at least a 4×8 block and an 8×8 block, and
wherein the determining is performed by a processor; and
decoding the 16×16 macroblock at the decoder using the at least one motion vector for each of the at least three regions,
wherein a first interpolation method is used for determining pixel values for a first of the at least three regions, wherein a second interpolation method is used for determining pixel values for a second of the at least three regions, and wherein the first interpolation method is different from the second interpolation method.
2. The method of claim 1 , wherein at least two motion vectors are used for each of the at least three regions.
3. The method of claim 1 , wherein the 16×16 macroblock is a P frame macroblock.
4. The method of claim 1 , wherein the 16×16 macroblock is a B frame macroblock.
5. A video decoder comprising:
a decoder configured to:
determine pixel values of at least a 16×16 macroblock, the 16×16 macroblock being partitioned into at least three regions, each of the at least three regions being adjacent to at least one of the other at least three regions,
receive at least one motion vector for each of the at least three regions,
wherein the at least three regions vary in block sizes, and
wherein the at least three regions include at least a 4×8 block and an 8×8 block, and
decode the 16×16 macroblock at the decoder using the at least one motion vector for each of the at least three regions,
wherein a first interpolation method is used to determine pixel values for a first of the at least three regions, wherein a second interpolation method is used to determine pixel values for a second of the at least three regions, and wherein the first interpolation method is different from the second interpolation method.
6. The video decoder of claim 5 , wherein at least two motion vectors are associated for each of the at least three regions.
7. The video decoder of claim 5 , wherein the 16×16 macroblock is a P frame macroblock.
8. The video decoder of claim 5 , wherein the 16×16 macroblock is a B frame macroblock.