Image processing apparatus and method
An image processing apparatus, including processing circuitry configured to decode a bit stream to generate quantized data. The bit stream includes a flag, for each block, that specifies whether or not a difference quantization parameter is present in the bit stream. The flag is included in a first layer that is higher than a second layer in which the difference quantization parameter is set. The processing circuitry is configured to set, according to the flag, a current quantization parameter for a current sub block formed by block partitioning, which splits a block into smaller sub blocks. The processing circuitry is configured to inversely quantize the generated quantized data using the set current quantization parameter.
1. An image processing apparatus, comprising:
processing circuitry configured to
set a flag, for each block, that specifies whether a difference quantization parameter is present in a bit stream;
set, according to the flag, a current quantization parameter for a current sub block formed by block partitioning, which splits a block into smaller sub blocks;
quantize transform coefficient data using the current quantization parameter to generate quantized data; and encode the quantized data to generate the bit stream that includes the flag and is included in a first layer that is higher than a second layer in which the difference quantization parameter is set.
2. The image processing apparatus according to claim 1 , wherein the processing circuitry is further configured to set the current quantization parameter for the current sub block using a value indicating a minimum sub block size for which the difference quantization parameter is set.
3. The image processing apparatus according to claim 1 , wherein the difference quantization parameter is a difference value between the current quantization parameter for the current sub block and a previous quantization parameter for a previous sub block.
4. The image processing apparatus according to claim 3 , wherein the previous sub block is a sub block that is decoded immediately before the current sub block in an order in which the bit stream is decoded.
5. The image processing apparatus according to claim 1 , wherein the difference quantization parameter is a difference value between the current quantization parameter set for the current sub block and a current slice quantization parameter set for a current slice.
6. The image processing apparatus according to claim 1 , wherein the processing circuitry is configured to set the flag as a syntax of the bit stream.
7. The image processing apparatus according to claim 1 , wherein the block is a largest coding unit (LCU) and the sub block is a coding unit, and the LCU is recursively split into the coding units.
8. An image processing method, comprising:
setting, with processing circuitry, a flag, for each block, that specifies whether a difference quantization parameter is present in a bit stream;
setting, according to the flag, a current quantization parameter for a current sub block formed by block partitioning, which splits a block into smaller sub blocks;
quantizing transform coefficient data using the current quantization parameter to generate quantized data; and encoding the quantized data to generate the bit stream that includes the flag and is included in a first layer that is higher than a second layer in which the difference quantization parameter is set.
9. The image processing method according to claim 8 , further comprising:
setting the current quantization parameter for the current sub block using a value indicating a minimum sub block size for which the difference quantization parameter is set.
10. The image processing method according to claim 8 , wherein the difference quantization parameter is a difference value between the current quantization parameter for the current sub block and a previous quantization parameter for a previous sub block.
11. The image processing method according to claim 10 , wherein the previous sub block is a sub block that is decoded immediately before the current sub block in an order in which the bit stream is decoded.
12. The image processing method according to claim 8 , wherein the difference quantization parameter is a difference value between the current quantization parameter set for the current sub block and a current slice quantization parameter set for a current slice.
13. The image processing method according to claim 8 , further comprising
setting the flag as a syntax of the bit stream.
14. The image processing method to claim 8 , wherein the block is a largest coding unit (LCU) and the sub block is a coding unit, and the LCU is recursively split into the coding units.