CPC H04N 19/122 (2014.11) [H04N 19/167 (2014.11); H04N 19/176 (2014.11); H04N 19/61 (2014.11)] | 3 Claims |
1. A method for decoding an image signal by an apparatus, comprising:
determining an input length and an output length of a non-separable transform based on a height and a width of a current block;
determining a non-separable transform matrix related to the input length and the output length of the non-separable transform;
applying the non-separable transform matrix for coefficients of the current block, a number of the coefficients being related to the input length of the non-separable transform; and
performing primary inverse transform on the coefficients for which the non-separable transform is applied,
wherein the input length and the output length of the non-separable transform are determined separately,
wherein the size of the non-separable transform matrix is determined as one of four predefined sizes, based on the height and the width of the current block,
wherein the input length of the non-separable transform is determined as 16 and the output length of the non-separable transform is greater than the input length of the non-separable transform, based on that both the height and the width of the current block are greater than 8, and
wherein the input length of the non-separable transform is determined as 8 and the output length of the non-separable transform is greater than the input length of the non-separable transform, based on that both the height and the width of the current block are equal to 8.
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