Video encoding method for encoding division block, video decoding method for decoding division block, and recording medium for implementing the same
Disclosed are a method of encoding a division block in video encoding and a method of decoding a division block in video decoding. An input picture is divided into encoding unit blocks. The coding unit (CU) blocks are divided into sub-CU blocks. The sub-CU blocks are encoded by selectively using at least one of intra prediction encoding and inter prediction encoding. A decoding process is performed through a reverse process of the encoding method. When pixel values of a CU block are encoded in video encoding, the flexibility in selecting an encoding mode is increased and the efficiency of encoding is increased.
1. A method of video decoding, comprising:
dividing a decoding unit block within a current slice into four first sub-decoding-unit-blocks;
dividing at least one of the first sub-decoding-unit-blocks within the decoding unit block into four second sub-decoding-unit-blocks, wherein a prediction mode for each of the second sub-decoding-unit-blocks has intra prediction mode or inter prediction mode, wherein at least one of the four of the second sub-decoding-unit-blocks has the intra prediction mode and the rest of the second sub-decoding-unit-blocks have the inter prediction mode;
transforming the at least one of the second sub-decoding-unit-blocks using a first transform kernel and a second transform kernel, wherein a size of the first transform kernel is different from a size of the second transform kernel, wherein the at least one of the second sub-decoding-unit-blocks is transformed using the first transform kernel and the second transform kernel which has different size from the first transform kernel, and the at least one of the second sub-decoding-unit-blocks is divided from the first sub-decoding-unit-block within the decoding unit block and the at least one of the second sub-decoding-unit-blocks has intra prediction mode or inter prediction mode; and
performing prediction on each of the second sub-decoding-unit-blocks according to the prediction mode for each of the second sub-decoding-unit-blocks,
wherein the performing prediction includes performing intra prediction on the second sub-decoding-unit-block having the intra prediction mode and inter prediction on the second sub-decoding-unit-block having the inter prediction mode,
wherein the inter prediction mode and the intra prediction mode are mixed in the decoding unit block,
wherein transforming the at least one of the second sub-decoding-unit-blocks includes transforming at least one of the first sub-decoding-unit-blocks which are undivided, by using a third transform kernel and a fourth transform kernel, wherein a size of the third transform kernel is different from a size of the fourth transform kernel, wherein the first sub-decoding-unit-block which is undivided has inter prediction mode or intra prediction mode,
wherein the size of the first transform kernel and the size of the second transform kernel are smaller than a size of the second sub-decoding-unit-block, and the size of the third transform kernel and the size of the fourth transform kernel are smaller than a size of the first sub-decoding-unit-block, and
wherein the decoding unit block includes at least one undivided first sub-decoding-unit-block which is basis of prediction mode and is divided into the third transform kernel and the forth transform kernel having different size from the third transform kernel, and the decoding unit block further includes the at least one of the second sub-decoding-unit-blocks which is basis of prediction mode and is divided into the first transform kernel and the second transform kernel having different size from the first transform kernel.
2. The method of claim 1 , wherein each of the second sub-decoding-unit-blocks selectively applies a variable block-size first transform kernel and second transform kernel according to a second sub-block size.
3. The method of claim 1 , wherein each of the second sub-decoding-unit-blocks is decoded by selectively applying one or more de-blocking filters according to the sub-decoding-unit-block size.
4. The method of claim 1 , wherein the decoding unit block is a square block of a larger size than a size of 16×16.