Method and apparatus for processing video signals using coefficient induced prediction
AssigneesLG Electronics Inc., University of Southern California
InventorsYung-Hsuan Chao, Sehoon Yea, Antonio Ortega
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Abstract
The present invention provides a method for encoding a video signal on the basis of a graph-based lifting transform (GBLT), comprising the steps of: detecting an edge from an intra residual signal; generating a graph on the basis of the detected edge, wherein the graph includes a node and a weight link; acquiring a GBLT coefficient by performing the GBLT for the graph; quantizing the GBLT coefficient; and entropy-encoding the quantized GBLT coefficient, wherein the GBLT includes a partitioning step, a prediction step, and an update step.
Claims6
A method of encoding a video signal based on a graph-based lifting transform (GBLT), comprising:
- detecting an edge from an intra residual signal, wherein a model for the intra residual signal is designed by using a Gaussian Markov Random Field (GMRF);
- generating a graph based on the edge, wherein the graph comprises a node and a weight link;
- obtaining a GBLT coefficient by performing the GBLT for the graph;
- quantizing the GBLT coefficient;
- and
- entropy-encoding the quantized GBLT coefficient,
- wherein the GBLT comprises a split process, a prediction process, and an update process,
- wherein the split process of the GBLT is performed to minimize a Maximum A Posteriori (MAP) estimate error within a prediction set, and
- wherein the method further comprises:
- obtaining a DCT coefficient by performing a DCT on the intra residual signal;
- comparing a rate-distortion cost of the DCT coefficient with a rate-distortion cost of the GBLT coefficient;
- determining, based on the rate-distortion cost of the GBLT coefficient being smaller than the rate-distortion cost of the DCT coefficient, a mode index corresponding to the GBLT;
- and
- entropy-encoding the mode index.
A method of decoding a video signal based on a graph-based lifting transform (GBLT), comprising:
- extracting a mode index indicative of a transform method from the video signal;
- deriving a transform corresponding to the mode index, wherein the transform indicates one of a DCT and the GBLT;
- performing an inverse transform for an intra residual signal based on the transform;
- and
- generating a reconstructed signal by adding the inverse-transformed intra residual signal to a prediction signal,
- wherein a model for the intra residual signal is designed by using a Gaussian Markov Random Field (GMRF),
- wherein the mode index is determined by comparing a rate-distortion cost of a DCT coefficient with a rate-distortion cost of a GBLT coefficient, and
- wherein a split process of the GBLT is performed to minimize a Maximum A Posteriori (MAP) estimate error within a prediction set.
An apparatus for encoding a video signal based on a graph-based lifting transform (GBLT), comprising:
- a processor configured to:
- detect an edge from an intra residual signal, wherein a model for the intra residual signal is designed by using a Gaussian Markov Random Field (GMRF);
- generate a graph based on the detected edge and obtaining a graph-based lifting transform (GBLT) coefficient by performing the GBLT for the graph;
- quantize the GBLT coefficient;
- and
- perform entropy encoding for the quantized GBLT coefficient,
- wherein the GBLT comprises a split process, a prediction process, and an update process,
- wherein the split process of the GBLT is performed to minimize a Maximum A Posteriori (MAP) estimate error within a prediction set, and
- wherein the processor is further configured to:
- obtain a DCT coefficient by performing a DCT on the intra residual signal;
- compare a rate-distortion cost of the DCT coefficient with a rate-distortion cost of the GBLT coefficient;
- determine, based on the rate-distortion cost of the GBLT coefficient being smaller than the rate-distortion cost of the DCT coefficient, a mode index corresponding to the GBLT;
- and
- entropy-encode the mode index.
An apparatus for decoding a video signal based on a graph-based lifting transform (GBLT), comprising:
- a processor configured to:
- extract a mode index indicative of a transform method from the video signal;
- derive a transform corresponding to the mode index and perform an inverse transform for an intra residual signal based on the transform;
- and
- generate a reconstructed signal by adding the inverse-transformed intra residual signal to a prediction signal,
- wherein a model for the intra residual signal is designed by using a Gaussian Markov Random Field (GMRF), and
- wherein the transform indicates one of a DCT and the GBLT,
- wherein the mode index is determined by comparing a rate-distortion cost of a DCT coefficient with a rate-distortion cost of a GBLT coefficient, and
- wherein a split process of the GBLT is performed to minimize a Maximum A Posteriori (MAP) estimate error within a prediction set.
Dependencies are inferred from the claim text.