Block-based progressive visual cryptography scheme with uniform progressive recovery and consistent background

Block-based progressive visual cryptography scheme (BPVCS) divides a secret image into non-overlapping blocks and encodes each block as sub-shadows. The final shadows for BPVCS are created by combining the associated sub-shadows. When enough shadows are superimposed, some of the secret blocks will be exposed. More information will be revealed as more shadows are used. This is referred to as progressive recovery. Hou et al. introduced a -BPVCS. Yang et al. further extended the scheme to a general scheme. However, Yang et al. -BPVCS suffers from the non-uniform progressive recovery and inconsistent background of recovered secret blocks. In this paper, we introduce a -BPVCS to address the mentioned two defects. Theoretical analysis and experimental results are provided to illustrate the benefits of the proposed approach.