Patent ID: 11863765
Assignee: IMAGINATION TECHNOLOGIES LIMITED
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 11:
12. The method of claim 11, wherein each pixel in the block of pixels has a further value in an Alpha channel, wherein the method further comprises:
determining a set of Haar coefficients for the Alpha channel of the 2×2 quad of pixels, wherein the set of Haar coefficients for the Alpha channel comprises a plurality of differential Alpha coefficients and an average Alpha coefficient;
determining a first Alpha portion of the compressed data structure using the differential Alpha coefficients determined for the 2×2 quad of pixels, wherein the first Alpha portion comprises:
a first set of Alpha bits which indicates an order of the magnitudes of the differential Alpha coefficients; and
a second set of Alpha bits which indicates a sign and an exponent for each of one or more of the differential Alpha coefficients which are non-zero; and

determining a second Alpha portion of the compressed data structure using the average Alpha coefficient determined for the 2×2 quad of pixels.