| 摘要 |
A method of manipulating spectral content of a block of pixels for compression includes the step (620) of classifying each pixel within a selected block (110) of pixels as relevant (114) or irrelevant (112). A forward transform is applied (720) to the selected block to generate a coefficient block. The coefficient values are modified (754) to generate a modified coefficient block subject to a set of pre-determined constraints including a constraint that the relevant pixels have a same value in an inverse transformation of the modified coefficient block as in the selected block. Proceeding (740) in a reverse zig zag coefficient order, the method is repeated for other coefficients having non-zero quantized values. |
