A hybrid block truncation coding (BTC) is presented in this work. In the hybrid ETC, a universal codebook using Ramming codes and a differential pulse code modulation (DPCM) are employed, respectively, to the bit plane and the side information of ETC to reduce coding rate. Simulation results reveal that the performance of the proposed algorithm is only slightly worse than that of the hybrid ETC using vector quantization (VQ) techniques, but with much lower computational or hardware complexity.
