Method and device for determining transform block size

An image decoding method comprising:

• obtaining a plurality of candidate transform block sizes according to a parameter of a transform block associated with an image block and a splitting manner of the image block;
• determining a plurality of identifiers for the plurality of candidate transform block sizes, where the plurality of identifiers is more than two;
• parsing a code stream to obtain an identifier of a transform block size of the transform block;
• and
• obtaining the transform block size according to the identifier of the transform block size;
• wherein the plurality of candidate transform block sizes includes three candidate transform block sizes of
• M×M, 2M×0.5M, and 0.5M×2M, wherein 2M×2M represents a size of the image block, or
• TL×TL, 2TL×0.5TL, and 0.5TL×2TL, wherein TL represents a basic size parameter TL corresponding to a transform block in each layer of transfer blocks.

An image coding device comprising:

• a processor;
• and
• a memory coupled to the processor and storing processor-executable instructions which, when executed, cause the processor to implement operations including:
• obtaining a plurality of candidate transform block sizes according to a parameter of a transform block associated with an image block and a splitting manner of the image block;
• determining a plurality of identifiers for the plurality of candidate transform block sizes, where the plurality of identifiers is more than two;
• and
• selecting one of the plurality of candidate transform block sizes as a size of the transform block associated with the image block and coding an identifier for the selected candidate transform block size into a code stream;
• wherein the plurality of candidate transform block sizes includes three candidate transform block sizes of
• M×M, 2M×0.5M, and 0.5M×2M, wherein 2M×2M represents a size of the image block, or
• TL×TL, 2TL×0.5TL, and 0.5TL×2TL, wherein TL represents a basic size parameter TL corresponding to a transform block in each layer of transfer blocks.

An image decoding device comprising:

• a processor, and
• a memory coupled to the processor, and storing processor-executable instructions which when executed cause the processor to implement operations including:
• obtaining a plurality of candidate transform block sizes according to a parameter of a transform block associated with an image block and a splitting manner of the image block;
• determining a pluarility of identifiers for the plurality of candidate transform block sizes, where the plurality of identifiers is more than two;
• parsing a code stream to obtain an identifier of a transform block size of the transform block;
• and
• obtaining the transform block size according to the identifier of the transform block size;
• wherein the plurality of candidate transform block sizes includes three candidate transform block sizes of
• M×M, 2M×0.5M, and 0.5M×2M, wherein 2M×2M represents a size of the image block, or
• TL×TL, 2TL×0.5TL, and 0.5TL×2TL, wherein TL represents a basic size parameter TL corresponding to a transform block in each layer of transfer blocks.