Pallette Image Compression

Figure 1. Sample Pallette Image

This work presents a fast and efficient way for color reindexing that tends to maximize the compression performance of a palette-based image. The proposed scheme relates the index difference of neighboring pixels to the potential cost of bits. It optimizes the assignment of index values to colors in a one-step look-ahead greedy fashion. Experimental results suggest that the proposed reindexing scheme can reduce the bit rate by up to 43%, when compared to a previously proposed intensity-based color-indexing scheme. Furthermore, we show that with the proposed color re-indexing scheme, the palette-based JPEG-LS and palette-based JPEG-2000 can often outperform GIF significantly.

For details of the work, please refer to the following paper.

©Copyright by Jin Li, June 22, 2001