A method for digital image compression using Discrete Wavelet Transform DWT

摘要

Methods, apparatuses and computer program products for encoding and decoding transform coefficients are disclosed. An digital image (102) is input to a transform block (110), which preferably employs a discrete wavelet transform. A bit rearrangement block (120) codes bit sequences representing resulting transform coefficients (112) in an efficient fashion. The bit arrangement block (120) selects a portion of the coefficients as a region (200). The significance of each bitplane of the region (200) is scanned from most towards least significant bitplanes, and first and second tokens are provided for each insignificant and significant bitplanes until determining a significant bitplane. This region is then partitioned into subregions (210-216), which are each set as the selected region. This processing is repeated until a minimum bit level is reached, or the selected region has a specified size. The coefficients of specified-size regions (200-216) are coded and provided in a coded representation (122). IMAGE