Method and apparatus for intra prediction within display screen
The present invention relates to a method and apparatus for intra prediction. The intra prediction method for a decoder, according to the present invention, comprises the steps of entropy-decoding a received bitstream, generating reference pixels to be used in the intra prediction of a prediction unit; generating a prediction block from the reference pixels on the basis of a prediction mode for the prediction unit and reconstructing an image from the prediction block and a residual block, which is obtained as a result of entropy encoding, wherein the reference pixels and/or the prediction block pixels are predicted on the basis of a base pixel, and the predicted pixel value can be the sum of the pixel value of the base pixel and the difference between the pixel values of the base pixel and the generated pixel.
1. A method of decoding a video signal with a decoding apparatus, the method comprising:
deriving reference samples for intra prediction of a current block based on at least one of neighboring samples adjacent to the current block;
obtaining a prediction sample of the current block by performing the intra prediction on a target sample of the current block based on a top reference sample having a same x-coordinate as the target sample and a variation relating to the reference samples, wherein the variation relating to the reference samples is representative of a difference value between a reconstructed value of a top-left reference sample whose a location is fixed regardless of a coordinate of the target sample and a reconstructed value of a left reference sample whose a location is determined dependent on the coordinate of the target sample, the left reference sample having a same y-coordinate as the target sample; and
deriving a reconstruction sample of the current block by adding the prediction sample and a residual sample relating to the current block.
2. An apparatus of decoding a video signal, the apparatus comprising:
a decoding apparatus configured to derive reference samples for intra prediction of a current block based on at least one of neighboring samples adjacent to the current block, configured to obtain a prediction sample of the current block by performing the intra prediction on a target sample of the current block based on a top reference sample having a same x-coordinate as the target sample and a variation relating to the reference samples, and configured to derive a reconstruction sample of the current block by adding the prediction sample and a residual sample relating to the current block,
wherein the variation relating to the reference samples is representative of a difference value between a reconstructed value of a top-left reference sample whose a location is regardless of a coordinate of the target sample and a reconstructed value of a left reference sample whose a location is determined dependent on the coordinate of the target sample, the left reference sample having a same y-coordinate as the target sample.