METHOD AND APPARATUS FOR SELECTING A SCAN PATH FOR THE ELEMENTS OF A BLOCK IN SPATIAL DOMAIN PICTURE ENCODING AND DECODING

摘要

International image or video coding standards uses hybrid coding, wherein a picture is separated into pixel blocks on which predictive coding, transform coding and entropy coding is employed. The transform coding is effective because the prediction error samples are correlated in the frequency domain. However, when the prediction quality is getting better and better, spatial domain coding becomes more effective than transform coding. According to the invention, it is first determined in which corner of a current block the first non-zero amplitude value is located. Based on the related zeroes run length value in that block, a pre-defined scan path is selected, i.e. a context-based adaptive scan mode is used.