Perceptual image compression via adaptive block- based super-resolution directed down-sampling

In this paper, we propose a novel perceptual image coding scheme via adaptive block-based super-resolution directed down-sampling. At the encoder side, for each macroblock of a given image, Rate Distortion Optimization (RDO) determines whether it is encoded at the original or down-sampled resolution. The down-sampling process is directed by super-resolution, which generates the down-sampled block by minimizing the reconstruction errors between the original macroblock and the one restored by the corresponding super-resolution method. At the decoder side, in order to reduce the complexity, the super-resolution method reconstructs the full-resolution macroblock in the DCT domain together with the inverse DCT. Experimental results have demonstrated that the proposed method can produce higher quality images in terms of both PSNR and visual quality compared with the existing methods.