Adaptive difference expansion-based reversible image watermarking method

Abstract

The invention discloses an adaptive difference expansion-based reversible image watermarking method, which comprises a watermark embedding process, a watermark extraction process and an image recovery process; before watermarks are embedded, the original image needs to be pretreated, and the pretreatment comprises alternated division, difference calculation, image complexity calculation and parameter setting; in the embedding process, the corresponding watermarks are embedded by using adaptive expansion; additional information is embedded, and the watermark data and the additional information are mixed and embedded under a specific condition; in the extraction process, the additional information is first extracted, and the difference is calculated; the inverse operation of the adaptive difference expansion is performed, the watermark data are extracted, and the original difference is reduced; and finally, the image is reduced through the reduced difference. The method has reversibility, and can provide higher embedding capacity and better image quality, particularly under the condition of many embedded watermark data.

Description

technical field [0001] The invention relates to a method for embedding and extracting a reversible image watermark, in particular to a reversible image watermark method based on adaptive difference expansion. Background technique [0002] The digital information revolution has brought profound changes to human society and life, and various digital media works have brought new challenges while enriching people's lives. The low cost of copying and distributing digital multimedia works makes digital piracy very common. Therefore, security issues such as digital copyright protection and content integrity verification have become urgent problems to be solved. Digital watermark hides some information in digital image, text, video or audio signal, and has become an effective means to protect the security of digital media content. In most existing digital watermarking methods, the host media will be permanently changed due to the embedding of the watermark signal and cannot be rest...

AI Technical Summary

Problems solved by technology

In most existing digital watermarking methods, the host media will be permanently changed due to the embedding of the watermark signal and cannot be restored to the state before the watermark is embedded.

Although the distortion introduced by the watermark is usually not easy to be detected by the human perception system, in some special fields that require extremely high data fidelity, such as military images, medical images, satellite remote sensing images, or legal evidence images, any tiny Distortion is not allowed

Therefore, the application of digital watermarking technology in these fields has been greatly restricted.

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