Transformation domain printing-scanning resistant digital watermarking method based on computer-generated holography

Abstract

The invention relates to a transformation domain printing-scanning resistant digital watermarking method based on computer-generated holography. The method integrates QR two-dimension codes, double random phase modulation encryption technique, a conjugate symmetry prolongation Fourier computer-generated holography technique and a wavelet transform technique, adopts the QR two-dimension codes as original watermarking information, preprocessed QR two-dimension code information is used for two-value watermarking so as to perform double random phase modulation encryption, finally the conjugate symmetry prolongation Fourier computer-generated holography technique is utilized to calculate amplitudes and phase information of complex images so as to obtain a watermarking hologram after holography technique records are encrypted. An image obtained by performing holographic decryption and double random phase modulation decryption on the hologram generated in the mode is free of noise, and the robustness of a watermarking algorithm is improved. The safety of the watermarking algorithm is improved by using the double random phase modulation encryption technique. The QR two-dimension codes form a two-value image and can carry copyright information and enable accurate copyright owner or group positioning to be possible.

Description

technical field [0001] The invention relates to a digital watermarking technology, in particular to a transform domain anti-printing and scanning digital watermarking method based on computational holography. Background technique [0002] In recent years, with the rapid development of computer and network communication technology, more and more attention has been paid to the copyright protection of digital products. However, copyright protection and anti-counterfeiting issues of printed matter are equally important. Research on digital watermarking technology against printing and scanning can carry out copyright protection on printed matter. It provides another new way for the copyright protection of printed matter. Since the watermark information hidden in the printed matter is severely damaged after secondary copying and scanning, it cannot be detected, so it can also be used as a means of anti-counterfeiting. Since the printing of images containing watermarks does not ...

AI Technical Summary

Problems solved by technology

[0004] The present invention aims at the problems existing in the robustness and objective evaluation of existing algorithms, and proposes a transformation domain anti-printing and scanning digital watermarking method based on computational holography. The present invention overcomes the defect of noise under the premise of ensuring safety , the noise interference is theoretically 0, so that the watermarking technology can accurately extract the QR two-dimensional code, enhance the robustness and security of the watermarking algorithm, and also provide an objective evaluation standard

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