Multi-secrets visual secret sharing

Visual secret sharing (VSS) is the well-known technique that encodes a secret image into several share images and, afterward, decodes the secret by superimposing the share images and recognizing by the human visual system. In this paper, a multi-secrets VSS which is extended from traditional VSS is presented. The codebook of traditional (2,2) VSS is adopted to generate share images macroblock by macroblock in such a way that multiple secret images are turned into only two share images and decode all the secrets one by one by stacking two of share images in a way of shifting.