5 results about "Ac coefficient" patented technology

The embodiment of the application provides a transform coefficient coding method, a transform coefficient decoding method and a terminal, and belongs to the technical field of coding and decoding. The transform coefficient coding method comprises the following steps: obtaining transform coefficients corresponding to a point cloud; the transform coefficients comprise a direct current (DC) coefficient and at least two alternating current (AC) coefficients; encoding the DC coefficient according to a first order corresponding to the DC coefficient and a context probability model corresponding to the DC coefficient; encoding each AC coefficient according to a second order corresponding to each AC coefficient and a context probability model corresponding to each AC coefficient; the second order is determined based on the first order and an index of a coding point corresponding to the AC coefficient; and generating a target code stream based on the encoding result of the DC coefficient and the encoding result of each AC coefficient.

Embodiments of the present application provide a point cloud encoding method, a point cloud decoding method, an encoder, a decoder, and a storage medium. The point cloud decoding method comprises: parsing a code stream, and determining a residual value of an AC coefficient of a current transform block, wherein the current transform block belongs to a first RAHT layer, and the first RAHT layer is any one of a plurality of RAHT layers of a point cloud of a current frame; determining a reconstructed value of the AC coefficient of the current transform block on the basis of the residual value of the AC coefficient of the current transform block; determining a reconstructed attribute value of the current transform block on the basis of the reconstructed value of the AC coefficient of the current transform block; determining whether to perform a filtering operation on the first RAHT layer; and if it is determined to perform the filtering operation on the first RAHT layer, filtering the reconstructed attribute value of the current transform block on the basis of a first group of filtering coefficients.

Provided in the embodiments of the present application are a point cloud encoding method, a point cloud decoding method, an encoder, a decoder, and a storage medium. The point cloud decoding method comprises: parsing a bitstream to determine residual values of AC coefficients of one or more transform blocks in a current RAHT layer, wherein the current RAHT layer is any one of a plurality of RAHT layers of a current frame; on the basis of the residual values of the AC coefficients of the one or more transform blocks, determining reconstructed values of the AC coefficients of the one or more transform blocks; on the basis of the reconstructed values of the AC coefficients of the one or more transform blocks, determining reconstructed attribute values of the one or more transform blocks; determining whether to adjust the reconstructed attribute values in the current RAHT layer; and if it is determined to adjust the reconstructed attribute values in the current RAHT layer, adjusting the reconstructed attribute values of the one or more transform blocks on the basis of a target offset value.

The embodiment of the application provides a transform coefficient coding method, a transform coefficient decoding method and a terminal, and belongs to the technical field of coding and decoding. The transform coefficient coding method comprises the following steps: determining a first columbus order corresponding to a DC coefficient according to an amplitude corresponding to the DC coefficient in transform coefficients; in the case that the transform coefficients comprise the DC coefficient, generating a target code stream according to the first columbus order corresponding to the DC coefficient and a coding result of the DC coefficient; or in the case that the transform coefficients comprise the DC coefficient and AC coefficients, performing at least one of the following operations: generating the target code stream based on the first columbus order corresponding to the DC coefficient, the coding result of the DC coefficient and a coding result of each AC coefficient; or determining a second columbus order corresponding to the AC coefficient according to the first columbus order and an amplitude corresponding to the first AC coefficient; and generating the target code stream based on the first columbus order corresponding to the DC coefficient, the coding result of the DC coefficient and the coding result of each AC coefficient.

Embodiments of the present application provide a point cloud encoding method, a point cloud decoding method, an encoder, a decoder, and a storage medium. The point cloud decoding method comprises: parsing a code stream, and determining a residual value of an AC coefficient of a current transform block, wherein the current transform block belongs to a first RAHT layer, and the first RAHT layer is any one of a plurality of RAHT layers of a point cloud of a current frame; determining a reconstructed value of the AC coefficient of the current transform block on the basis of the residual value of the AC coefficient of the current transform block; determining a reconstructed attribute value of the current transform block on the basis of the reconstructed value of the AC coefficient of the current transform block; determining whether to perform a filtering operation on the first RAHT layer; and if it is determined to perform the filtering operation on the first RAHT layer, filtering the reconstructed attribute value of the current transform block on the basis of a first group of filtering coefficients.