Method and apparatus for image and video coding using hierarchical sample adaptive band offset
A method and apparatus for image coding using hierarchical sample adaptive band offset. The method includes decoding a signal of a portion of an image, determining a band offset type and offset of a portion of the image, utilizing the band offset type and offset to determine a sub-band, and reconstructing a pixel value according to the determined offset value.
1. A system comprising:
a video capture component configured for capturing a sequence of pictures, each picture represented by an array of component pixel values for one or more components, each component pixel value comprising binary word;
a video encoder component coupled to the video capture component, the video encoder component configured for:
dividing video information pertaining to a picture into coding units;
determining a starting band for band offset sample adaptive filtering for a coding unit, the starting band identified by five most significant bits of each component pixel value associated with the starting band; and
determining offset values for four contiguous bands including the starting band and three adjacent bands;
an entropy encoder coupled to the video encoder, the entropy encoder configured for encoding the sample adaptive starting band, and exactly four offset values, each of the four offset values for one of the four contiguous bands; and
a transmitter coupled to the entropy encoder and configured for transmitting entropy encoded data.
2. The system of claim 1 , the video encoder component configured for determining the starting band and the offset values by reconstructing component pixel values for the coding unit and using the reconstructed component pixel values to determine the starting band and the offset values.
3. The system of claim 1 , the video encoder component configured for generating a merge signal indicating the coding unit is to utilize sample adaptive offset parameters from another coding unit.
4. The system of claim 1 , the video encoder component configured for generating a starting band and four offset values for a block of luma component pixel values.
5. The system of claim 1 , the video encoder component configured for generating a starting band and four offset values for a block of chroma component pixel values.
6. The system of claim 1 , the video encoder component configured for generating, for each chroma component in a block of pixel values, a separate starting band and four separate offset values.
7. The system of claim 1 , the video encoder component configured for generating a single starting band and a single set of four offset values for both the luma component and all chroma components in a block of pixel values.
8. The system of claim 1 , the video encoder component configured for generating a starting band and four offset values for the luma component in a block of pixel values, and generating a single starting band and a single set of four offset values for all chroma components in a block of pixel values.
9. A method of encoding video comprising:
capturing a sequence of pictures, each picture represented by an array of component pixel values for one or more components, each component pixel value comprising binary word;
dividing video information pertaining to a picture into coding units;
determining a starting band for band offset sample adaptive filtering for a coding unit, the starting band identified by five most significant bits of each component pixel value associated with the starting band; and
determining offset values for four contiguous bands including the starting band and three adjacent bands;
encoding the sample adaptive starting band, and exactly four offset values, each of the four offset values for one of the four contiguous bands; and
transmitting entropy encoded data.
10. The method of claim 9 , comprising reconstructing component pixel values for the coding unit and using the reconstructed component pixel values to determine the starting band and the offset values.
11. The method of claim 9 , comprising generating a merge signal indicating the coding unit is to utilize sample adaptive offset parameters from another coding unit.
12. The method of claim 9 , comprising generating a starting band and four offset values for a block of luma component pixel values.
13. The method of claim 9 , comprising generating a starting band and four offset values for a block of chroma component pixel values.
14. The method of claim 9 , comprising generating, for each chroma component in a block of pixel values, a separate starting band and four separate offset values.
15. The method of claim 9 , comprising generating a single starting band and a single set of four offset values for both the luma component and all chroma components in a block of pixel values.
16. The method of claim 9 , comprising generating a starting band and four offset values for the luma component in a block of pixel values, and generating a single starting band and a single set of four offset values for all chroma components in a block of pixel values.
17. The system of claim 1 , the video encoder component configured for mapping two most significant of the five most significant bits to a two bit value with one bit of the two bit value indicating whether the starting band identified by the five most significant bits is in a middle range of potential starting bands.
18. The system of claim 1 , the video encoder component configured for determining the starting band and offset values for a first video component, and further determining additional offset values for a second video component.
19. The method of claim 9 , further comprising mapping two most significant of the five most significant bits to a two bit value with one bit of the two bit value indicating whether the starting band identified by the five most significant bits is in a middle range of potential starting bands.
20. The method of claim 9 , further comprising determining additional offset values for a second video component.