Mode adaptive intra prediction smoothing in video coding
A method for decoding an encoded video bit stream in a video decoder is provided that includes decoding an intra prediction mode for a block of pixels encoded in the video bit stream, determining, based on the intra prediction mode, whether or not a smoothing filter is to be applied to reference pixel values used for intra prediction of the block, applying a smoothing filter to the reference pixel values when a result of the determining is that a smoothing filter is to be applied, and performing intra prediction according to the intra prediction mode using the smoothed reference pixel values to generate a predicted block of pixels.
1. A method for decoding an encoded video bit stream in a video decoder, the method comprising:
decoding an intra prediction mode for a block of pixels encoded in the video bit stream;
determining, based on the intra prediction mode, whether or not a smoothing filter is to be applied to reference pixel values used for intra prediction of the block;
selecting a smoothing filter to be applied to the reference pixel values from a plurality of smoothing filters based on the intra prediction mode in response to determining that the smoothing filter is to be applied;
applying the selected smoothing filter to the reference pixel values to generate smoothed reference pixel values in response to determining that the smoothing filter is to be applied; and
performing intra prediction according to the intra prediction mode using the smoothed reference pixel values to generate a predicted block of pixels.
2. The method of claim 1 , wherein the determining is further based on a smoothing flag encoded in the video bit stream.
3. The method of claim 1 , wherein the smoothing filter consists of a [1 2 1] filter, a [1 1 4 1 1] filter, and a [1] filter.