A (k, n) threshold secret image sharing scheme, abbreviated as (k, n)-TSISS, splits a secret image into n shadow images in such a way that any k shadow images can be used to reconstruct the secret image exactly. In 2002, for (k, n)-TSISS, Thien and Lin reduced the size of each shadow image to 1 k of the original secret image. Their main technique is by adopting all coefficients of a (k − 1)-deg...