Patent ID: 8478060

Claim:
A method for compressing an image, the method comprising associating perceptual importance parameters with pixels of the image, applying a transform on the image, partitioning the transformed image into code blocks and partitioning a given code block into sub-blocks, using an average of the perceptual importance parameters of the pixels, to which the coefficients of the given code block correspond, for determining a preliminary truncation bit plane for said given code block, encoding coefficient bits of said given code block together from a most significant bit plane towards a least significant bit plane, wherein encoding of coefficient bits is truncated individually at sub-block dependent truncation bit planes, each of said sub-block dependent truncation bit planes being dependent on the perceptual importance parameters associated with pixels to which the coefficients of the respective sub-block correspond, wherein the encoding of coefficients of at least one sub-block is truncated at an advanced truncation bit plane and encoding of coefficients comprised in at least another sub-block is truncated at a reduced truncation bit plane wherein an average truncation bit plane of the sub-blocks corresponds to said preliminary truncation bit plane.