Embedding and extraction method of medical image zero watermark based on real fractional Fourier transform

Abstract

The invention discloses a medical image zero watermarking embedding and extracting method based on real fractional Fourier transform and belongs to the technical field of information safety and image processing. According to the medical image zero watermarking embedding and extracting method based on the real fractional Fourier transform, the own characteristics of an image are utilized for structuring watermark information rather than modified, it is guaranteed that original image information does not change in the embedding process of a watermark, the embedded information amount is large, and the demands of authenticity and reliability of medical images are met. The method combines the real fractional Fourier transform theory, the image encryption theory and the zero watermarking technology, on the premise that high fidelity characteristics of the medical images are guaranteed, the robustness and the safety of the watermark are taken into consideration, the algorithm is simple and fast, realization cost is low, and the method has high practical value.

Description

technical field [0001] The invention belongs to the technical fields of information security and image processing, and in particular relates to a zero-watermark embedding and extraction method of medical images based on real-fractional Fourier transform. Background technique [0002] With the continuous development of Internet technology, digital multimedia products are more and more vulnerable to malicious attacks and illegal misappropriation in the process of storage, dissemination, and use; for digital multimedia products, how to effectively and conveniently protect copyrights has become an urgent problem to be solved. digital watermarking technology is an effective method to realize copyright protection, and its basic idea is to secretly embed valuable information in digital multimedia information without affecting the use of digital multimedia, so as to achieve the purpose of copyright protection of digital products . [0003] As an important basis for clinical diagnos...

AI Technical Summary

Problems solved by technology

Since the common digital watermarking technology more or less changes the characteristics of the original image and cannot meet the high-fidelity requirements of medical images, it is urgent to seek a new means of copyright protection for medical images.

[0004] The existing methods for medical image copyright protection mainly include: reversible medical watermarking algorithm, medical watermarking algorithm based on non-interest region, compressed domain watermarking algorithm, etc.; reversible medical watermarking algorithm mainly adopts a reversible thinking mode, that is, in After the watermark is extracted, the image can be restored to its original state without distortion, thereby eliminating the distortion caused by watermark embedding; although reversible digital watermarking has its own advantages, the amount of data that can be embedded is small, and the safety factor is not high , the protection of medical images only exists during the transmission process. Once it reaches the terminal, it will return to the original state and no longer have a protective effect; the medical watermarking algorithm based on the non-interest area is to embed the watermark information in the non-interest area of ​​the medical image ; Since most medical images have a black background, the amount of information hiding is very limited, and the process of finding non-interest regions of medical images is very cumbersome, which usually requires manual intervention, which increases the complexity and workload of the algorithm; The medical watermarking algorithm is to embed the watermark in the compressed domain, that is, to embed the watermark directly into the coded compressed bit stream

The advantage of this algorithm is that it avoids a large number of encoding and decoding processes, so the computational complexity is low, it will not cause the decline in the quality of medical image data, and it will give full play to the advantages of time; however, due to the limitation of the compression bit rate In addition to the amount of data embedded in the watermark, the embedding method is also limited by the corresponding image compression algorithm standard.

Images