Watermark adding and extraction method in digital image

Abstract

The invention provides a watermark adding and extraction method in a digital image. The watermark adding method in the digital image comprises the steps that a target carrier image and a watermark image to be added are acquired; the target carrier image is coded; frequency domain transformation and first quantitative coding processing are performed on the obtained first color coded carrier image; singular value decomposition is performed on the watermark image, and the obtained first diagonal matrix is embedded the coded first high frequency band signals; the obtained U-matrix and the V-matrix are embedded in the coded first low frequency band signals; and a second color coded carrier image obtaining the watermark image is obtained according to the result of two times of embedding. Complete watermark information can still be extracted out of the a second color coded carrier image containing the watermark after printing and scanning, and the second color coded carrier image containing the watermark can be decoded and character information can be acquired so that the objectives of copyright protection and counterfeiting prevention through combination of the color two-dimensional codes and the digital watermark can be achieved.

Description

technical field [0001] The invention relates to the technical field of digital graphics processing, in particular to a method for adding and extracting watermarks in digital images. Background technique [0002] As an important branch of information hiding technology, digital watermarking technology is a new type of information security protection technology. The basic idea is to embed the digital information containing the author's electronic signature, date, trademark, usage rights, etc. as a watermark signal into the target carrier image of the digital work, but it will not affect the recognition of the target carrier image itself. And when necessary, the watermark can be extracted through certain technical detection means, as evidence for judging the copyright ownership of digital works and tracking and prosecuting illegal infringement. [0003] At present, there are many transformation domain digital watermarking technologies based on two-dimensional codes, but there a...

AI Technical Summary

Problems solved by technology

[0003] At present, there are many transformation domain digital watermarking technologies based on two-dimensional codes, but there are few studies on the combination of color two-dimensional codes and watermarking algorithms. At present, the transformation domain digital watermarking methods based on two-dimensional codes basically use the original watermark information, and the above-mentioned original watermark information is a meaningless binary watermark image, which has a great impact on the integrity of watermark information extraction after being subjected to geometric attacks, and affects the robustness of the watermark algorithm; digital images containing watermarks are digitally printed or After printing and scanning by the scanner, the obtained watermarked digital image is attacked by printing and scanning, and the watermark information recovered from it will become unclear, so we can only rely on subjective judgment to measure whether the watermark exists

[0004] The inventor found in the research that the two-dimensional code-based transformation domain digital watermarking method provided by the prior art is less robust, and no effective solution has been proposed for this problem

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