Digital watermark method against geometrical attack based on image characteristic region

Abstract

A digital watermark method resisting against geometric attack includes relating watermark information to image character region, generating local character region with invariance on geometric attack by utilizing most stable Harris character point in image, making said region to be round character region by image normalization, carrying out two-stages of wavelet transforms on these round character regions, selecting revision coefficient regions to embed watermark at the second stage wavelet transform and realizing watermark-embedding. The method for picking up watermark is also disclosed.

Description

technical field [0001] The present invention relates to the technical field of information security, specifically a digital watermarking method, which can effectively resist geometric attacks such as translation, rotation, and local shearing, as well as conventional signal processing attacks, and can be used for digital images on the Internet. Copyright Protection. Background technique [0002] The rapid development of computer technology and Internet technology makes it easy for people to share resources. The use of digital images, audio and video has also greatly facilitated their widespread dissemination on the Internet, but at the same time it has also created a serious problem of copyright protection. Digital watermarking technology is considered to be an advantageous means of copyright protection for digital images. It embeds certain copyright information into images and extracts them as proof of copyright owners when copyright disputes occur. Since the early 1990s, ...

AI Technical Summary

Problems solved by technology

[0011] (2) In the watermark embedding process, the original watermark needs to be converted into the same size and shape as the triangle image block, and the triangle image block needs to be transformed into the same size and shape as the original watermark during watermark detection. These two processes There is an interpolation operation in , which leads to difference errors and affects the detection of watermarks

Therefore, when the image is attacked by noise, filtering, etc., it will directly affect the watermark information, so the algorithm has poor performance for such attacks

When the image is subjected to geometric attacks such as rotation and scaling, the error caused by interpolation will also have a direct impact on watermark detection.

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