Cost Effective Block Truncation Coding for Color Image Compression

In this paper, a cost effective block truncation coding (CE-BTC) using low cost approach is presented for color image compression. To reduce the bit rate of the basic BTC, selected single bit-map is employed to represent the edge information of the coding block in the proposed CE-BTC. Moreover, a previous proposed algorithm, adaptive quantization coding (AQC), is used to compress the two representative levels further. In order to achieve low cost, the CE-BTC reduces the line buffer memory usage to a half with the limited PSNR losing of 0.02dB compared with the optimal approach. Simulation results show that the proposed CE-BTC outperforms vector quantization-BTC up to 3 dB in PSNR. The comparison with our previous research AHIC also shows that an improvement of 0.425 dB in average PSNR is achieved by the CE-BTC.