Lossless image compression using adjustable fractional line-buffer

Video frame memory compression has gained increased popularity in video processing ICs to save external memory storage size and reduce memory access bandwidth. This technique is especially important in portable devices where efficient use of energy is critical for the deployment of video applications. In this paper, we propose a low-complexity lossless image compression method that uses only a fraction of one line-buffer. The proposed method first employs integer wavelet transform (IWT), and then low-frequency coefficients prediction of each segment based on those from the segment in the line above, and last Golomb-Rice (GR) encoding to achieve low-cost and highly efficient compression. Simulation results demonstrate that the proposed method gives a compression ratio comparable with the existing state-of-the-art low-complexity methods while significantly lowering the internal memory cost and keeping the complexity low.