A (m, m)VCS with consistent size reconstruction using full binary tree

Visual cryptography method of secret sharing suffers from pixel expansion and low contrast. Such kind of problem persist in approximately all previous existing visual cryptographic algorithm whereas there are few visual cryptographic method which tries to improve but not done with whole similarity. In this proposed method, we have designed a hierarchical visual cryptographic method which doesn´t suffer from any pixel expansion and found similar contrast as the original image. It uses the concept of full binary tree for generating share in (m, m) VCS up to n-1^th (started from zero) level of its height where only left child in left sub-tree and right child in right sub-tree are further divided. A small size binary image of factor size of one of leftmost share in left sub-tree is used to generate key by doing XOR operation with this share and resultant share works as a key in this process.