Encrypted holographic watermark algorithm of transform domain based on copyright protection

• Main Authors: SUN LIUJIE, ZHANG LEIHONG, LI MENGTAO, WANG HONGLAI
• Format: Patent
• Language: Chinese; English
• Published: 09.11.2011
• Subjects: CALCULATING; COMPUTING; COUNTING; IMAGE DATA PROCESSING OR GENERATION, IN GENERAL; PHYSICS

The invention relates to an encrypted holographic watermark algorithm of a transform domain based on copyright protection, comprising the following steps of: carrying out random double-phase modulation on watermark information to generate a watermark holographic image; then carrying out 4*4 partitioning on an L component of a carrier image in a Lab space; carrying out DCT (Discrete Cosine Transformation) conversion on each partition; extracting a middle-low frequency coefficient of each matrix to form a new matrix and carrying out wavelet decomposition on the new matrix; embedding the watermark holographic image into the middle-low frequency wavelet coefficient to obtain an embedded colorful image; and then extracting the watermark image again by directionally operating the steps. The watermark has good invisibility and higher safety by carrying out random double-phase encryption on the watermark image; and the original image is not needed in the step of extracting the watermark image, and the watermark belon