Digital watermarking method based on 2DPCA (two-dimensional principal component analysis)

Abstract

The invention provides a digital watermarking method based on 2DPCA (two-dimensional principal component analysis), belonging to the field of digital watermarking. The method comprises the following steps of: pre-processing an image: performing various non-linear geometrical transform to the primary image to obtain a new image after each transform, extracting an image characteristic vector matrix and an image principal component matrix; watermarking pre-processing; watermarking embedding; recovering the image; and watermarking extracting. As the characteristic vector matrix which is used for extracting the image principal component matrix is unchanged, even though each valve of the image principal component matrix is changed, the fluctuation range of the data in the image principal component matrix is approximately similar; i leading out principal components are selected from the principal component matrix of the primary image; namely, weight values of i different principal components representing image information are accumulated, and the accumulation sum is within the range of 0.4-0.9; and the i leading out principal components are subjected from discrete cosine transform or Fourier transform. The invention, under the precondition of ensuring robustness and invisibility of the digital watermarking, effectively resists attack from the non-linear geometry.

Description

Technical field: [0001] The invention belongs to the field of digital watermarking, and in particular relates to a digital watermarking algorithm based on 2DPCA and capable of resisting local nonlinear geometric attacks. Background technique: [0002] The robust digital watermarking algorithm emphasizes the ability of the algorithm to resist various attacks, that is, after the carrier has experienced various intentional or unintentional operations (attacks), the watermark embedded in it can still be extracted or detected. In terms of robust image digital watermarking research, researchers have successively studied conventional signal processing attacks such as filtering and noise addition; compression attacks such as JPEG compression and JPEG2000 compression; global geometric attacks such as rotation, scaling, and translation. [0003] But in the real world, there are often local nonlinear geometric attacks. This kind of attack is very easy to implement with image processin...

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Problems solved by technology

[0003] But in the real world, there are often local nonlinear geometric attacks

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