Markov Matrix and Entropy based Tamper Detection Technique for Text Images

Abstract

In this paper, a novel watermarking technique for the tamper detection of text images is pro-posed. Entropy of every sentence is computed and converted to Unicode Zero Width Characters (ZWCs) by using a lookup table. These ZWCs values are embedded at the end of every sentence after terminator. On receiver side, entropy value embedded in every sentence is extracted and converted to numerical form using the same lookup table. Entropy of every sentence is re-calculated and compared with extracted values for tamper detection. Comparison of technique with existing state-of-art techniques shows the effectiveness of the proposed technique.