Medical-image robust multiple-watermark method based on DWT (Discrete Wavelet Transform) and DCT (Discrete Cosine Transform)

Abstract

The invention relates to a medical-image robust multiple-watermark method based on DWT (Discrete Wavelet Transform) and DCT (Discrete Cosine Transform). The method comprises the following steps of: firstly, carrying out embedding of multiple watermarks, wherein the step comprises (1) carrying out DWT on the original medical image, then carrying out whole-image DCT on approximation subimages, and extracting a vector which can represent the important visual feature of the original image in conversion coefficients; (2) utilizing the feature vector and the multiple watermarks to be embedded to obtain a corresponding two-valued logic sequence by virtue of a Hash function, storing the two-valued sequence in a third party and then carrying out extraction of multiple watermarks; (3) carrying out DWT on the medical image to be detected, then carrying out DCT on the approximation subimages, and finding a visual feature vector of the image to be detected; and (4) utilizing the property of the Hash function and the two-valued logic sequence stored in the third party to extract the multiple watermarks. The medical-image robust multiple-watermark method can be used for solving the problems of the geometric attack resistance and conventional attack resistance occurring in the application of the medical image so as to protect the secrecy of information of patients.

Description

technical field [0001] The invention belongs to the field of multimedia signal processing, and relates to a medical image multiple digital watermarking technology based on wavelet transform (DWT), discrete cosine transform (DCT) and image visual features, in particular to a medical image robust multiple watermarking technology based on DWT and DCT method. Background technique [0002] In recent years, with the rapid development of computer science technology and multimedia communication technology, digital information management system has played an increasingly important role in the modern medical system. With the advancement of software and hardware conditions, especially the emergence of new equipment such as high-resolution computed tomography (CT) and magnetic resonance imaging (MRI) and advanced optical scanners and the development of a series of related software, The effect of medical images has made a qualitative leap. With the popularization and application of the...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a robust multi-watermarking method for medical images based on DWT and DCT. By organically combining the visual feature vector of medical images, encryption technology and the concept of a third party, there is no need to select regions of interest. It solves the problem of quickness and capacity limitation of multi-watermark embedding and extraction, has ideal robustness and invisibility, effectively solves the problem of multiple digital watermarks in medical images, and solves the problem of multiple digital watermarks in medical image applications. The problem of resisting geometric attacks and resisting conventional attacks to protect the confidentiality of patient information

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