Research Article

Weighted Polynomial-Based Secret Image Sharing Scheme with Lossless Recovery

Algorithm 2

The recover procedure of the weighted polynomial-based SIS scheme.
(1)Input: shadow images and the corresponding participant serial number ,
(2)Output: the original secret image
(3)Step 1. Repeat Steps 2–4 for each pixel of the shadow image, where .
(4)Step 2. Judge whether the share pixel value is invalid value 0 or 255. Only if it is valid, it will participate in the recovery.
(5)Step 3. Calculate Lagrange interpolation in the field of by the formula . Then, set to obtain .
(6)Step 4. .
(7)Step 5. Output the recovered image .