Processing method of reversible watermark on the basis of local positioning and ALattar integer transform

Abstract

The invention discloses a processing method of a reversible watermark on the basis of local positioning and Alattar integer transform. The method utilizes the mean value invariance of the Alattar integer transform to evaluate the local texture characteristics of an image block, and specifically, whether the image block is positioned in a smooth area or not is judged through a degree of correlation between the mean value of the certain image block and all pixels surrounding the image block. In order to keep a high visual quality, the image blocks positioned in the smooth area are subjected to watermark embedding, and the image blocks positioned in a texture complicity area are kept constant. A thought that the local texture characteristics of the image blocks are evaluated by the mean value invariance is utilized to solve the problem that a location plan can not be effectively compressed when an embedding rate is low in an Alattar method so as to realize a high PSNR (Power Signal-to-Noise Ratio) value when the embedding rate is low. In a word, the processing method can efficiently compress the location plan through the introduction of the local positioning so as to improve embedding performance.

Description

technical field [0001] The invention belongs to the field of multimedia signal processing, in particular to a reversible watermark processing method based on local positioning and Alattar integer transformation. Background technique [0002] Digital watermarking technology refers to a technology that embeds some logos or signatures in digital multimedia without being noticed. Digital watermarking technology plays a vital role in some applications, such as copyright protection, authentication, and data integrity of digital media. However, the traditional digital watermarking technology usually introduces some subtle and irreversible distortions to the carrier image, and even causes permanent distortion of the host image, but in some practical applications, it is not allowed to have an Minor permanent modifications, such as in areas such as medical, military, and judicial. Taking medical images as an example, any form of distortion is not allowed. The acquisition of any medi...

AI Technical Summary

Problems solved by technology

In Wang Xiang's method, even if a certain pixel differs greatly from its mean value, the same bit must be embedded into this pixel, so for this pixel, the embedding distortion is relatively high

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