Image self-embedding semi-fragile watermark method and system based on block truncation coding

• Main Authors: GONG DAOFU, MO CHENGYU, WANG YILONG, LI ZHENYU, TAN LEI, LU HAOYU, LIU FENLIN
• Format: Patent
• Language: Chinese; English
• Published: 17.12.2021
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; IMAGE DATA PROCESSING OR GENERATION, IN GENERAL; PHYSICS

The invention discloses an image self-embedding semi-fragile watermark method based on block truncation coding. The method comprises the following steps of: watermark generation and embedding: firstly, carrying out block-level two-level division on an image, and respectively generating image blocks with the granularity of 4 * 4 and 2 * 2; then, carrying out compression coding on each 4 * 4 image block by utilizing block truncation coding to generate a recovery watermark of a 2 * 2 image block, and carrying out Hash on the recovery watermark to generate an authentication watermark of the 2 * 2 image block; finally, cascading the recovery watermark and the authentication watermark to form a self-embedded watermark, and embedding the self-embedded watermark into a 4 * 4 mapping block; tampering authentication and recovery: firstly, comparing a watermark extracted from a certain 4 * 4 image block with a watermark generated by the block, and judging whether a 2 * 2 sub-block of the image block passes authenticatio