Reversible watermark method for image certification

Abstract

The invention relates to a reversible watermark method used in image identification, belonging to multimedia information safety technique, wherein the invention modifies high-frequency sub-band histogram to embed the SHA-256 Haxi value of original image and the data used to recover image into high-frequency sub-band; via replacing the most low bit plane of low-frequency sub-band to embed the useful watermark into low-frequency sub-band; based on extracted watermark or the differential value picture between extracted watermark and former watermark to process falsification check and positioning; comparing extracted Haxi value and the Haxi value of returned image to process content completeness check. The invention can resist false impact, check and position falsification, to return original image without aberration.

Description

technical field [0001] The invention belongs to the technical field of multimedia signal processing, and in particular relates to a reversible watermark method for image authentication, which has a large embedding capacity, can resist forgery attacks, and has the function of tampering and positioning. Background technique [0002] Digital images have been widely used, but they are easily tampered or even forged during transmission and storage. It has become a need for the information society to authenticate the authenticity and integrity of digital image content, especially in military, medical, and news Image authentication is essential for sensitive and precious image applications such as publishing. [0003] Digital watermarking technology can be used for image authentication, and has received great attention from researchers. Through the search, the relevant comparable authorized patents are as follows: [0004] [1] J.M.Barton, "Method and apparatus for embedding authe...

AI Technical Summary

Problems solved by technology

The methods of the first and second types use lossless compression technology, so the amount of calculation is large, and the system implementation is more complicated. For pictures with complex textures, lossless compression technology cannot provide enough embedding capacity, so it is often difficult to be practical

However, the method of patent [2] in the third method leads to poor visual quality of the image to be certified, because the change of the edge pixel value is too large

For image authentication methods and technologies, tampering location is a very important content and function. Unfortunately, in the existing literature and patents we know, except Celik method can provide tampering location function, other methods cannot provide tampering location function

The Celik method adopts a content-based, self-adaptive, lossless image compression encoding and decoding method, and the embedded capacity is small. For pictures with complex textures, it is difficult to apply lossless compression technology, and it is not suitable for pictures with complex textures.

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