IWT-Schur-based region-of-interest reversible watermark embedding and extracting method

Abstract

The invention relates to an IWT-Schur-based region-of-interest reversible watermark embedding and extracting method. The method comprises steps of during watermark embedding, firstly, performing wavelet decomposition on a carrier image, screening to obtain a region-of-interest coefficient of each component, then encrypting the watermark by using Arnold transformation, carrying out integer wavelettransformation on the scrambled watermark to obtain a series of sub-bands, and finally, correspondingly embedding each sub-band of the watermark into each sub-band ROI of the carrier image by using matrix Schur decomposition. Compared with the prior art, the method has the advantages that nondestructive recovery of the region of interest is guaranteed, it is guaranteed that the watermark is completely embedded into the whole region of interest, and the watermark can better adapt to the ROI coding characteristic.

Description

technical field [0001] The invention relates to the field of computer information security, in particular to an IWT-Schur-based reversible watermark embedding and extraction method for an area of ​​interest. Background technique [0002] With the development of digital multimedia technology, JPEG2000 compression standard came into being with superior performance. The JPEG2000 standard should meet the application requirements of compressed images. It has the incomparable performance of JPEG compression. It is based on wavelet transform, and its core is embedded block coding with optimized truncation (EBCOT), which supports lossless and Lossy compression. JPEG2000 supports region-of-interest coding, that is, it supports different coding precisions for each part of the image. In addition, there are many advantages in performance: (1) ROI coding, JPEG2000 supports different coding precisions for different regions in the same image. (2) Progressive transmission, including four...

AI Technical Summary

Problems solved by technology

Most of these algorithms embed the watermark by changing the wavelet coefficients, for example, add the watermark sequence in two ways in the ROI background area (region of background, ROB), and finally extract the watermark information in the form of the mean value. However, the embedding position of this method is selected in The optimal truncation of the embedded block encoding module, the watermark module can easily affect the normal encoding and decoding process of JPEG2000, and the embedding cost is relatively high

In addition, existing technologies include embedding data such as patient health records as watermarks into regions of interest. This scheme can accurately detect and locate tampered regions within ROIs and completely restore the original ROIs, but this method is only For medical images, not suitable for JPEG2000 images

The algorithm of using Harris-Laplace operator to detect feature points and construct and screen regions of interest is one of the common algorithms in recent years. It uses block truncation coding technology based on point diffusion to extract ROI features, and combines ROI features and watermarks to generate keys. Realize zero watermark, although this method can effectively protect image ROI data and improve robustness, but this method is greatly affected by cropping processing, which limits its application

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