Partial secret image sharing for (k,n) threshold based on image inpainting

The traditional (k,n) threshold secret image sharing (SIS) schemes dealt with the full secret image neglecting the possible situation that only part of the secret image needs protection. However, in some applications, only target part of the secret image may need to be protected while other parts may be not in a full image. In this paper, we consider the partial secret image sharing (PSIS) issue as well as propose a PSIS scheme for (k,n) threshold based on image inpainting and linear congruence (LC)-based SIS. The full secret image including the secret target part and other parts will be recovered by collecting any k or more shadow images, which can be further reconstructed losslessly by adding all the inpainted meaningful shadow images. Furthermore, the proposed scheme can share irregular target in a progressive way. Experiments are conducted to evaluate the efficiency of the proposed scheme.