DWT-SVD robust blind watermark method based on multilevel DCT

Abstract

The invention relates to a DWT-SVD robust blind watermark method based on multilevel DCT. The method comprises a watermark embedding method and a watermark extraction method. The watermark embedding method includes the steps that discrete waterlet transformation is conducted on an original image, a low-frequency sub-band of the original image is divided into small blocks, multilevel DCT is conducted on each small block, chaotic encryption is conducted on watermarks to be embedded, multilevel DCT coefficients of each small block form a new matrix, and the encrypted watermarks are embedded into a singular value matrix of each new matrix. The watermark extraction method is the inverse process of the watermark embedding method and includes the steps of extraction of the encrypted watermarks and decryption and restoration of the watermarks through secret keys. According to the method, by the combination of the advantages of DWT and SVD on the digital watermark respect and the utilization of the energy concentration characteristic of multilevel DCT, data of which values are large are acquired, the embedded capacity of the watermarks is increased, the characteristic of being good in robustness is still maintained, and the problem of conflicts between the capacity of the watermarks and robustness is well solved.

Description

technical field [0001] The invention belongs to the technical field of information security, in particular to a discrete wavelet transform and singular value decomposition (DWT-SVD) robust watermarking method based on multilevel discrete cosine transform (DCT). Background technique [0002] Because of its important application value in copyright protection and content authentication, digital watermarking technology has become a research hotspot in information hiding technology. Digital watermarking technology embeds information such as numbers, serial numbers, text, and image logos into the media, and modifies the carrier as little as possible during the embedding process to achieve the strongest robustness. When the watermarked media is attacked After that, the watermark can still be recovered or the existence of the watermark can be detected. With the rapid development of information security requirements, invisible watermarking is getting more and more researchers' atten...

AI Technical Summary

Problems solved by technology

Most of the existing robust watermarking algorithms only consider the robustness, while sacrificing the watermarking capacity, so it has a negative impact on the large-scale practical promotion of such algorithms