METHOD AND APPARATUS FOR DETERMINING A CONTEXT MODEL FOR TRANSFORM COEFFICIENT LEVEL ENTROPY ENCODING AND DECODING

摘要

Provided are a method and apparatus for determining a context model for entropy encoding and decoding of a transformation coefficient. According to the method and apparatus, a context set index ctxset is obtained based on color component information of a transformation unit, a location of a current subset, and whether there is a significant transformation coefficient having a value greater than a first critical value in a previous subset, and a context offset c1 is obtained based on a length of a previous transformation coefficient having consecutive 1s. Also, a context index ctxids for entropy encoding and decoding of a first critical value flag is determined based on the obtained context set index and the context offset.

主权项

1. A method of determining a context model for entropy encoding and decoding of a transformation coefficient level, the method comprising:
splitting a transformation unit into subsets having a predetermined size and obtaining a significant transformation coefficient that is included in each of the subsets and is not 0; obtaining a context set index for determining a context set used in entropy encoding and decoding of a first critical value flag indicating whether the significant transformation coefficient from among a plurality of context sets including a plurality of contexts has a value greater than a first critical value, based on color component information of a transformation unit, location information of a first subset in which the significant transformation coefficient is included, and whether there is a significant transformation coefficient having a value greater than the first critical value in a second subset that is processed before the first subset; obtaining a context offset for determining one of a plurality of contexts included in a context set used in entropy encoding and decoding of the first critical value flag based on a length of a previous transformation coefficient having consecutive 1s; and obtaining a context index indicating a context used in entropy encoding or decoding of the first critical value flag by using the context set index and the context offset.