Joint mode decision with shared bit-budget condition

摘要

Apparatus and method for optimizing encoding and decoding when using embedded block coding, in which each block is independent coded is described. Instead of coding the whole block in response to a single mode decision, the block is separated into multiple sub-blocks sharing the same block bit budget. A block is divided for example in response to color or spatial considerations. A joint mode decision is then made where mode (DPCM/PCM) as well as qn are independently determined for each sub-block, while optimizing the use of the overall bit budget by sharing bits between the sub-blocks through refinement bits.