Image data encoding/decoding method and apparatus

A method of encoding a current image with an encoding apparatus, comprising:

• dividing a coding block in the current image to obtain one or more sub-blocks;
• obtaining transform coefficients of a first sub-block by performing transform on a residual signal of the first sub-block, the first sub-block belonging to the one or more sub-blocks;
• obtaining quantized transform coefficients of the first sub-block by performing quantization on the transform coefficients of the first sub-block;
• and
• generating a bitstream by encoding the quantized transform coefficients of the first sub-block,
• wherein the residual signal is obtained based on a prediction signal corresponding to the residual signal,
• wherein the prediction signal is generated by determining a prediction method for the coding block and performing prediction for coding block based on the determined prediction method,
• wherein the determined prediction method is encoded into the bitstream using prediction information,
• wherein the prediction method is determined as one among a plurality of prediction methods including an inter prediction method,
• wherein coding information for dividing the coding block is encoded into the bitstream,
• wherein the coding information includes a first flag indicating whether to divide the coding block to obtain the one or more sub-blocks, a second flag indicating whether to divide the coding block asymmetrically, and a third flag indicating whether a division direction for the coding block is a horizontal direction or a vertical direction, the first flag, the second flag and the third flag being different from each other,
• wherein the coding information further includes information on a division position of each of the one or more sub-blocks within the coding block,
• wherein, in case the coding block is divided asymmetrically, the first sub-block having a ¼ size of the coding block is obtained, and
• wherein obtaining the quantized transform coefficients of the first sub-block comprises:
• selecting one of a plurality of weight set candidates pre-defined in the encoding apparatus;
• and
• performing the quantization on the transform coefficients of the first sub-block based on the selected weight set candidate.

A non-transitory computer-readable medium for storing data associated with an image signal, comprising:

• a data stream encoded by an encoding method,
• wherein the encoding method comprises:
• dividing a coding block in the current image to obtain one or more sub-blocks;
• obtaining transform coefficients of a first sub-block by performing transform on a residual signal of the first sub-block, the first sub-block belonging to the one or more sub-blocks;
• obtaining quantized transform coefficients of the first sub-block by performing quantization on the transform coefficients of the first sub-block;
• and
• generating a bitstream by encoding the quantized transform coefficients of the first sub-block,
• wherein the residual signal is obtained based on a prediction signal corresponding to the residual signal,
• wherein the prediction signal is generated by determining a prediction method for the coding block and performing prediction for coding block based on the determined prediction method,
• wherein the determined prediction method is encoded into the bitstream using prediction information,
• wherein the prediction method is determined as one among a plurality of prediction methods including an inter prediction method,
• wherein coding information for dividing the coding block is encoded into the bitstream,
• wherein the coding information includes a first flag indicating whether to divide the coding block to obtain the one or more sub-blocks, a second flag indicating whether to divide the coding block asymmetrically, and a third flag indicating whether a division direction for the coding block is a horizontal direction or a vertical direction, the first flag, the second flag and the third flag being different from each other,
• wherein the coding information further includes information on a division position of each of the one or more sub-blocks within the coding block,
• wherein, in case the coding block is divided asymmetrically, the first sub-block having a ¼ size of the coding block is obtained, and
• wherein obtaining the quantized transform coefficients of the first sub-block comprises:
• selecting one of a plurality of weight set candidates pre-defined in the encoding apparatus;
• and
• performing the quantization on the transform coefficients of the first sub-block based on the selected weight set candidate.

A method for transmitting data associated with an image signal, the method comprising:

• obtaining a data stream encoded by an encoding method;
• and
• transmitting the data stream,
• wherein the encoding method comprises:
• dividing a coding block in the current image to obtain one or more sub-blocks;
• obtaining transform coefficients of a first sub-block by performing transform on a residual signal of the first sub-block, the first sub-block belonging to the one or more sub-blocks;
• obtaining quantized transform coefficients of the first sub-block by performing quantization on the transform coefficients of the first sub-block;
• and
• generating a bitstream by encoding the quantized transform coefficients of the first sub-block,
• wherein the residual signal is obtained based on a prediction signal corresponding to the residual signal,
• wherein the prediction signal is generated by determining a prediction method for the coding block and performing prediction for coding block based on the determined prediction method,
• wherein the determined prediction method is encoded into the bitstream using prediction information,
• wherein the prediction method is determined as one among a plurality of prediction methods including an inter prediction method,
• wherein coding information for dividing the coding block is encoded into the bitstream,
• wherein the coding information includes a first flag indicating whether to divide the coding block to obtain the one or more sub-blocks, a second flag indicating whether to divide the coding block asymmetrically, and a third flag indicating whether a division direction for the coding block is a horizontal direction or a vertical direction, the first flag, the second flag and the third flag being different from each other,
• wherein the coding information further includes information on a division position of each of the one or more sub-blocks within the coding block,
• wherein, in case the coding block is divided asymmetrically, the first sub-block having a ¼ size of the coding block is obtained, and
• wherein obtaining the quantized transform coefficients of the first sub-block comprises:
• selecting one of a plurality of weight set candidates pre-defined in the encoding apparatus;
• and
• performing the quantization on the transform coefficients of the first sub-block based on the selected weight set candidate.