Quality-adaptive visual secret sharing by random grids
Visual secret sharing (VSS), classified into visual-cryptography (VC)-based and random-grid (RG)-based, suffers from the contrast problem that the reconstructed secret with low visual quality is not easy to recognize. Even worse, the more share images stacked, the lower visual quality of reconstructed secrets revealed. Therefore, it is promising to remove this innate drawback. In this paper, with security still kept, the light transmission of share images generated by the proposed scheme is redesigned to be higher than before such that the better visual quality of reconstructed secrets is obtained. To demonstrate the feasibility, the experimental results show the reconstructed secrets are visually recognizable and the goal that the more share images stacked, the better quality of reconstructed secrets we have is achieved.