Positioning vulnerable water print generating and recognizing method capable of distigushing image and watermark distortion

Abstract

The invention discloses orientation flimsy watermark generating and certificating method which can distinguish image and juggled watermark. Original image's wavelet low frequency coefficient of 4 bits is scalar quantized and used as watermark. The watermark is disturbed using random number to encrypt to improve its security. The encrypted watermark is embedded into LSB bit of original image. Original image's general picture is displayed through original watermark image's low frequency compress image recovered from watermark when certificating. Combining juggled position of image information located by difference value images with difference between image information and juggled watermark, how attacker juggled the image can be directly judged. At the premise of guaranteeing image's authenticity, switch efficiency of digital image is improved, which is helpful for digital images' application and spread. Adopting the invention, the authentication result is direct, visual effect is good, key's space is bigger and watermark algorithm is safer.

Description

Technical field [0001] The invention relates to a positioning-type fragile watermark embedding and authentication method, which is used for digital image authentication, that is, to prove the integrity and authenticity of the digital image. Background technique [0002] In recent years, with the development of computer and multimedia technology, more and more attention has been paid to the copyright protection and content authentication of digital products. It is against this background that digital watermarking is produced and has attracted extensive attention from the academic circles. The research on robust watermarking for copyright protection has been relatively in-depth, but for the content integrity authentication of digital products, that is, the credibility of transmitted multimedia data, robust watermarking technology cannot fully meet this requirement, while fragile watermarking technology can Make it happen. Fragile watermarks usually should meet the following p...

AI Technical Summary

Problems solved by technology

Its shortcoming is that it can only point out the tampering position of the watermark image (embedded watermark image), but cannot distinguish the tampering of the high seven-bit image information or the tampering of the lowest watermark

Since the tampering of image information will destroy the use value of the original image, the fragile watermarking algorithm must be able to detect and accurately locate such tampering to ensure the reliability and validity of the authentication; while the tampering of the watermark does not affect the use value of the image, this An image whose watermark has only been tampered with should pass the authentication, otherwise it will not pass the authentication indiscriminately, so that the image that could have been directly used must be retransmitted, thereby reducing the exchange efficiency of digital images, causing the real image not to be used effectively. Hinder the promotion and application of digital images

For example: if digital images used as evidence in litigation are authenticated and identified using the above methods, the requirements are too harsh and unfair; Information is viewed with suspicion, preventing the timely dissemination of news

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