A pvo digital watermarking method based on block merging strategy

Abstract

The invention belongs to the technical field of digital watermarking and discloses a PVO digital watermarking method based on a blocking merging strategy. The method comprises steps of carrying out embedding of PVO on blocks whose complexity degree is smaller than T1; merging the first layer: calculating the complexity degree of merged blocks again and carrying out embedding of the PVO according to a threshold value T2; merging the second layer: for blocks failing to meeting requirements, merging blocks meeting requirements into a 4*4 block according to position relations between adjacent blocks; and calculating the complexity degree of merged blocks again and carrying out embedding of the PVO according to a threshold value T3. According to the invention, by calculating the similarity, the blocks are merged layer by layer from small to big, so dynamic control of the size of the blocks is achieved, relativity of pixels in the blocks is effectively improved, it is achieved that less image distortion is acquired under the same embedding capacity, the peal signal to noise ratio PSNR of images after embedding is greatly increased and the method can be used for reversible hiding of secret information.

Description

technical field [0001] The invention belongs to the technical field of digital watermarking, in particular to a PVO digital watermarking method based on block merging strategies. Background technique [0002] In recent years, in the fields of military, medical, remote sensing image processing, etc., the original image is analyzed and studied, and the reversible watermarking technology is proposed by adjusting the information of the human eye to the insensitive area in the image. After extracting the watermark, the original image can be restored without error; one of the techniques of pixel value sorting (PVO) has received a lot of attention. After the original image is divided into blocks of equal size, the pixels in the given block are divided into The values ​​are sorted, and then data embedding is achieved by modifying the maximum and minimum values ​​of each chunk. For a given embedding capacity, the optimal block size is finally searched to minimize the embedding disto...

AI Technical Summary

Problems solved by technology

PVO embedding performance has a significant correlation with its chunk size; using a fixed chunking scheme greatly limits the capability of the scheme

[0003] To sum up, the problem existing in the existing technology is: in the PVO watermarking scheme, the fixed block scheme greatly limits the ability of the scheme

PVO embedding performance has a clear correlation with the block size. Using larger blocks can get higher performance, but it leads to a reduction in embedding capacity; in order to meet higher embedding capacity, smaller blocks must be used. resulting in reduced image quality

Images