DCT-Based Embedded Image Compression With a New Coefficient Sorting Method

This letter presents a new sorting algorithm for the DCT-based embedded image compression. The magnitudes of DCT coefficients are estimated from the ones in the neighboring blocks, and the coefficients with larger estimates are given higher priority in encoding. This priority information is also used as contexts for arithmetic coding. The proposed method finds more significant coefficients earlier than the conventional methods, thereby providing higher coding gain.