Size Reduction of a Share in Visual Secret Sharing Schemes

摘要

To reduce the size of a share in k-out-of-n visual secret sharing schemes, we propose a method such that the contrast is changed probabilistically. Although t (< k) shares generated with the proposed method do not leak the information on an original image, k shares provide sufficient information to recover the original image perfectly. The quality of the recovered image is nearly equal to that of previous schemes.