Method and apparatus for performing intra-prediction using adaptive filter
Provided is a method and apparatus for performing intra-prediction using an adaptive filter. The method for performing intra-prediction includes the steps of: determining whether or not to apply a first filter for a reference pixel value on the basis of information of a neighboring block of a current block; applying the first filter for the reference pixel value when it is determined to apply the first filter; performing intra-prediction on the current block on the basis of the reference pixel value; determining whether or not to apply a second filter for a prediction value according to each prediction mode of the current block, which is predicted by the intra-prediction performance on the basis of the information of the neighboring block; and applying the second filter for the prediction value according to each prediction mode of the current block when it is determined to apply the second filter.
1. A video decoding method, comprising:
determining whether to apply a first filter to a reference pixel value of a current block based on at least one of an intra prediction mode of the current block and a size of the current block;
deriving a prediction value of the current block using the reference pixel value; and
determining whether to apply a second filter for the prediction value of the current block based on at least one of the intra prediction mode of the current block and the size of the current block, for thereby producing a filtered prediction value,
wherein, when the intra prediction mode of the current block is a horizontal mode, the filtered prediction value is generated by applying the second filter for uppermost pixels block among prediction pixels of the current block adjacent to the reference pixel value, and
wherein the second filter is applied by using at least three of reference pixel values.
2. The video decoding method of claim 1 , wherein the intra prediction mode of the current block is determined based on a Most Probable Mode (MPM).
3. The video decoding method of claim 1 , wherein when the intra prediction mode of the current block is the horizontal mode, the second filter is applied by using a left reference pixel value, upper reference pixel values and an upper-left corner reference pixel value, the left reference pixel value corresponding to a left-side of an upper-leftmost pixel of the current block, the upper reference pixel values corresponding to upper-sides of the uppermost pixels of the current block.
4. A video encoding method comprising:
encoding information related to whether to apply a first filter to a reference pixel value of a current block and whether to apply a second filter for a prediction value of the current block,
wherein the information is related to at least one of an intra prediction mode of the current block and a size of the current block,
wherein, when the intra prediction mode of the current block is a horizontal mode, the filtered prediction value is generated by applying the second filter for uppermost pixels among prediction pixels of the current block adjacent to the reference pixel value, and
wherein the second filter is applied by using at least three of reference pixel values.
5. A non-transitory computer-readable storage medium storing a bitstream, the bitstream comprising:
information related to whether to apply a first filter to a reference pixel value of a current block and whether to apply a second filter for a prediction value of the current block,
wherein the information is related to at least one of an intra prediction mode of the current block and a size of the current block,
wherein, when the intra prediction mode of the current block is a horizontal mode, the filtered prediction value is generated by applying the second filter for uppermost pixels among prediction pixels of the current block adjacent to the reference pixel value, and
wherein the second filter is applied by using at least three of reference pixel values.