Lossless progressive secret sharing for grayscale and color images

A new technique on progressive secret sharing is presented. The proposed method offers two different approaches on converting a secret image into a set of shared images. The first approach exploits the generalized random grids or bitwise level computation, whereas the second approach utilizes the eXclusive-OR (XOR) operation to generate a set of shared images. The proposed method has lossless ability in the recovery process of secret image. This scheme performs well not only for binary image, but it also gives satisfactory result for grayscale and color secret image. As results show that the proposed method yields better results compared to the former existing schemes under visual investigation and objective assessment on the recovered secret image. In addition, the proposed method does not require high computational burden in the shared image generation as well as in the secret image recovery process. Yet, it can be regarded as good candidate for applying the progressive secret sharing with lossless reconstruction constraint.