Bit Packing For Delta Color Compression

An apparatus comprising:

• a compressor configured to:
• determine delta values for a plurality of pixels in a block, wherein each delta value represents a difference between a color of one of the plurality of pixels and a reference color of a reference pixel selected from the plurality of pixels;
• subdivide the plurality of pixels in the block into a plurality of groups;
• and
• transmit a compressed bitstream representative of the delta values, wherein the compressed bitstream includes bits representative of a block header that indicates a range of numbers of bits that are sufficient to represent the delta values, a plurality of group headers that each indicate a group minimum number of bits that is sufficient to represent the delta values in a corresponding one of the plurality of groups, and wherein the delta values have been encoded using the group minimum number of bits for the group that includes the delta values.

An apparatus comprising:

• a decompressor configured to:
• receive a compressed bitstream representative of delta values of a plurality of pixels in a block, wherein the compressed bitstream includes bits representative of a block header that indicates a range of numbers of bits that are sufficient to represent the delta values, a plurality of group headers that each indicate a group minimum number of bits that is sufficient to represent the delta values in a corresponding one of the plurality of groups, and wherein the delta values have been encoded using the group minimum number of bits for the group that includes the delta values;
• and
• decompress the compressed bitstream based on the block header, the plurality of group headers, and the encoded delta values to recover the delta values that each represent a difference between a color of one of the plurality of pixels and a reference color of a reference pixel selected from the plurality of pixels.