Patent attributes
A method and decoding unit for decoding a compressed data structure that encodes a set of Haar coefficients for a 2×2 quad of pixels of a block of pixels. The set of Haar coefficients comprises a plurality of differential coefficients and an average coefficient. A first portion of the compressed data structure encodes the differential coefficients for the 2×2 quad of pixels. A second portion of the compressed data structure encodes the average coefficient for the 2×2 quad of pixels. The first portion of the compressed data structure is used to determine signs and exponents differential coefficients which are non-zero. The second portion of the compressed data structure is used to determine a representation of the average coefficient. The result of a weighted sum of the differential coefficients and the average coefficient for the 2×2 quad of pixels is determined using: (i) the determined signs and exponents for the differential coefficients which are non-zero, (ii) the determined representation of the average coefficient, and (iii) respective weights for the differential coefficients. The determined result is used to determine the decoded value. The determined decoded value is outputted.
