Method for coding and decoding scalable video and apparatus using same
The present invention relates to a method and an apparatus for interlayer intra-prediction, and the method for interlayer intra-prediction, according to the present invention, comprises the steps of: deciding whether to apply an interlayer prediction to an enhancement layer; and performing a prediction on a current block of the enhancement layer based on reference information that is generalized and generated from a reference picture, which is decoded, of a reference layer, when the interlayer prediction is applied.
1. An interlayer prediction decoding method, using one or more processors and a memory, the method comprising:
obtaining a residual block with respect to a current block from an input bitstream;
determining whether to apply interlayer prediction to an enhancement layer;
performing prediction on the current block of the enhancement layer based on a picture of a reference layer, in response to a determination that the interlayer prediction is to be applied; and
reconstructing the current block based on the residual block and a prediction block obtained by performing the prediction on the current block,
wherein performing the prediction on the current block comprises:
reconstructing the picture of the reference layer by decoding the input bitstream including the reference layer;
generating, from the reconstructed picture of the reference layer, a generalized reference picture for interlayer prediction of a current picture of the enhancement layer;
constructing a reference picture list for the current picture by adding the generalized reference picture to at least one reference picture belonging to a same enhancement layer as the current picture; and performing the prediction on the current block of the enhancement layer based on the reference picture list and motion information of the current block.
2. The method of claim 1 , wherein whether to apply the interlayer prediction to the enhancement layer is determined based on a flag information indicating the interlayer prediction.
3. The method of claim 1 , wherein the generalized reference picture is generated by upsampling the reconstructed picture of the reference layer according to a picture size of the enhancement layer.
4. The method of claim 3 , wherein the upsampling is performed by applying a filter with predetermined filter coefficients to the reconstructed picture of the reference layer.
5. The method of claim 4 , wherein the filter with the predetermined filter coefficients is representative of either a first filter with a fixed filter coefficients or a second filter with adaptive filter coefficients which are variable according to a slice, a picture, or a block.
6. The method of claim 1 , wherein the motion information of the current block is derived based on motion information of a co-located block within the generalized reference picture.
7. An interlayer prediction encoding method, using one or more processors and a memory, the method comprising:
obtaining a residual block with respect to a current block from an input bitstream;
determining whether to apply interlayer prediction to an enhancement layer;
performing prediction on the current block of the enhancement layer based on a picture of a reference layer, in response to a determination that the interlayer prediction is to be applied; and
reconstructing the current block based on the residual block and a prediction block obtained by performing the prediction on the current block,
wherein performing the prediction on the current block comprises:
reconstructing the picture of the reference layer by decoding the input bitstream including the reference layer;
generating, from the reconstructed picture of the reference layer, a generalized reference picture for interlayer prediction of a current picture of the enhancement layer;
constructing a reference picture list for the current picture by adding the generalized reference picture to at least one reference picture belonging to a same enhancement layer as the current picture; and
performing the prediction on the current block of the enhancement layer based on the reference picture list and motion information of the current block.