JP2021002797A5 - - Google Patents

Claims (10)

An image decoding device that reversely converts the conversion coefficient for each conversion unit.
A second conversion unit that applies the inverse secondary conversion to the above conversion coefficients,
It is provided with a first conversion unit that applies an inverse core conversion to the conversion coefficient after conversion by the second conversion unit.
The second conversion unit includes either or both of the first syntax, which is a syntax indicating the secondary transformation decoded from the coded data, and the first variable, which is a variable derived from the intra prediction mode . An image decoding device characterized in that a one-dimensional conversion coefficient after secondary conversion is set to a two-dimensional conversion coefficient . The second conversion unit uses the first syntax and / or both of the first variables to set the one-dimensional conversion coefficient to the two-dimensional conversion coefficient. The image decoding apparatus according to claim 1, wherein the range is switched. The second conversion unit uses the first syntax and / or both of the first variables to derive a second variable, which is a variable indicating the arrangement of the variables after the secondary conversion. The image decoding apparatus according to claim 1 , wherein the one-dimensional conversion coefficient is set to the two-dimensional conversion coefficient by using the second variable . The second conversion unit uses the coordinates x or y of the two-dimensional conversion coefficient and the values at the coordinates x or y of a predetermined table to convert the one-dimensional conversion coefficient into the two-dimensional. The image decoding apparatus according to any one of claims 1 to 3, wherein the conversion coefficient is set or not set . The image decoding apparatus according to claim 3, wherein the second conversion unit switches a predetermined table according to the second variable . The image decoding apparatus according to claim 2 , wherein the second conversion unit switches whether the coordinates that are arguments of a predetermined table are x-coordinates or y-coordinates according to the intra-prediction mode . The second conversion unit sets a range symmetric with respect to 90-degree rotation and a range not symmetric as a range for performing secondary conversion for setting the one-dimensional conversion coefficient to the two-dimensional conversion coefficient. The image decoding apparatus according to any one of claims 1 to 6, wherein the image decoding apparatus is used . An image coding device that converts the predicted residuals for each conversion unit.
The first conversion unit that applies the core conversion to the predicted residual,
In an image coding apparatus including a second conversion unit that applies a secondary conversion to the conversion coefficient after conversion by the first conversion unit.
The second conversion unit is one-dimensional after the secondary conversion by one or both of the first syntax, which is a syntax indicating the secondary conversion, and the first variable, which is a variable derived by the intra prediction mode . An image coding apparatus characterized in that a conversion coefficient is set to a two-dimensional conversion coefficient . The second conversion unit uses one or both of the first syntax and the first variable to perform a secondary conversion that sets the one-dimensional conversion coefficient to the two-dimensional conversion coefficient. The image coding apparatus according to claim 8, wherein the range is switched. The second conversion unit uses the first syntax and / or both of the first variables to derive a second variable, which is a variable indicating the arrangement of the variables after the secondary conversion. The image coding apparatus according to claim 8, wherein the one-dimensional conversion coefficient is set to the two-dimensional conversion coefficient by using the second variable .