Method and apparatus for processing video signal on basis of combination of pixel recursive coding and transform coding
The present invention provides a method for encoding a video signal by using an enhanced prediction signal, the method comprising the steps of: generating a prediction signal for a current block, wherein the prediction signal is generated by applying a prediction weight to a reconstructed pixel of the current block and a pixel of a motion-compensated previously decoded block; obtaining an optimal quantized transform coefficient for the current block through rate-distortion optimization, on the basis of the prediction signal; and performing entropy encoding of the optimal quantized transform coefficient.
1. A method for encoding a video signal by an apparatus for encoding the video signal using an enhanced prediction signal, comprising:
generating a prediction signal for a current block, wherein the prediction signal is generated by applying a prediction weight to a reconstructed pixel of the current block and a pixel of a motion-compensated previously decoded block;
obtaining an optimal quantized transform coefficient for the current block by a rate-distortion optimization based on the prediction signal; and
entropy-encoding the optimal quantized transform coefficient,
wherein the prediction weight is generated based on a predetermined block type.
2. The method of claim 1 , wherein:
the predetermined block type is divided into a plurality of categories, and
the plurality of categories comprises at least one of a horizontal type, a vertical type, a diagonal type, a non-diagonal type or a smooth type.
3. The method of claim 2 , wherein the plurality of categories is classified based on a score obtained by filtering the motion-compensated previously decoded block.
4. The method of claim 3 , wherein:
a 5-tap flattening filter is used to determine a score of the smooth type, and
a 3-tap directional filter is used to determine a score of remaining types.
5. The method of claim 1 , further comprising
transmitting a pixel recursive transform flag indicating whether the optimal quantized transform coefficient is obtained by the rate-distortion optimization based on the prediction signal.
6. A method for decoding a video signal by an apparatus for decoding the video signal using an enhanced prediction signal, comprising:
entropy-decoding the video signal;
inverse-quantizing the entropy-decoded video signal to obtain a transform coefficient;
reconstructing a residual signal by performing an inverse-transform on the transform coefficient;
generating a prediction signal for a current block of the video signal; and
reconstructing the video signal by adding the reconstructed residual signal to the prediction signal,
wherein the prediction signal is generated by applying a prediction weight to a reconstructed pixel of the current block and a pixel of a motion-compensated previously decoded block, and
wherein the prediction weight is generated based on a predetermined block type.
7. The method of claim 6 , wherein:
the predetermined block type is divided into a plurality of categories, and
the plurality of categories comprises at least one of a horizontal type, a vertical type, a diagonal type, a non-diagonal type or a smooth type.
8. The method of claim 7 , wherein the plurality of categories is classified based on a score obtained by filtering the motion-compensated previously decoded block.
9. The method of claim 8 , wherein:
a 5-tap flattening filter is used to determine a score of the smooth type, and
a 3-tap directional filter is used to determine a score of remaining types.
10. The method of claim 6 , further comprising
transmitting a pixel recursive transform flag indicating whether the optimal quantized transform coefficient is obtained by the rate-distortion optimization based on the prediction signal.
11. An apparatus for encoding a video signal using an enhanced prediction signal, comprising:
a prediction unit to generate a prediction signal for a current block;
a transform unit to obtain an optimal quantized transform coefficient for the current block by a rate-distortion optimization based on the prediction signal; and
an entropy encoding unit to entropy-encode the optimal quantized transform coefficient,
wherein the prediction signal is generated by applying a prediction weight to a reconstructed pixel of the current block and a pixel of a motion-compensated previously decoded block, and
wherein the prediction weight is generated based on a predetermined block type.
12. The apparatus of claim 11 , wherein the transform unit transmits a pixel recursive transform flag indicating whether the optimal quantized transform coefficient is obtained by the rate-distortion optimization based on the prediction signal.
13. An apparatus for decoding a video signal using an enhanced prediction signal, comprising:
an entropy decoding unit to entropy-decode the video signal;
a dequantization unit to obtain a transform coefficient by inverse-quantizing the entropy-decoded video signal;
a transform unit to reconstruct a residual signal by performing an inverse transform on the transform coefficient;
a prediction unit to generate a prediction signal for a current block of the video signal; and
a reconstruction unit to reconstruct the video signal by adding the reconstructed residual signal to the prediction signal,
wherein the prediction signal is generated by applying a prediction weight to a reconstructed pixel of the current block and a pixel of a motion-compensated previously decoded block, and
wherein the prediction weight is generated based on a predetermined block type.