Progressive JPEG decoding system

摘要

An apparatus and a method for efficient decoding progressive JPEG bitstreams are invented. This invention provides a memory-efficient progressive JPEG decoding method with minimal memory requirements. Instead of storing all the DCT coefficients of at particular decoding scan, a portion of DCT coefficients and the non-zero coefficient indicators for the rest of the DCT coefficients are stored in either original data format or in a compressed format. The memory requirement for decoding progressive JPEG pictures can be minimized according to the resolution of display devices in the real applications.