Perceptual image coding

Classical transform based coders performed excellently in reducing statistical redundancies. However, reduction of statistical redundancies does not always correspond to the reduction of psychovisual redundancies. The removal of visually redundant information has potential advantages. First, it ensures that only visually important information is encoded, thus maintaining visual quality. Second, discarding visually redundant information leads to better compression performance. Therefore, incorporating properties of the HVS to coding structures is seen as a beneficial step in enhancing the visual performance of image coders.