Holographic anti-counterfeiting algorithm based on shape of screen dot

Abstract

The invention relates to a holographic anti-counterfeiting algorithm based on the shape of a screen dot. The holographic anti-counterfeiting algorithm based on the shape of the screen dot comprises the steps of processing an original digital image through the minimum threshold screening technology to generate a halftone image; transforming a two-value original watermark image to generate Fourier transform encrypted holographic data, splicing the data and performing binaryzation on the data to generate a new data matrix; embedding watermarks into the generated halftone image according to the generated data matrix to obtain an screening image containing anti-counterfeiting information; performing printing, collecting the screening image, judging and extracting anti-counterfeiting information according to the shape of the screen dot, multiplying the extracted information with a randomly-encrypted phase mask hologram image, and performing inverse Fourier transform to obtain original anti-counterfeiting information. By means of the screen dot carrying the anti-counterfeiting information, special information is given to the screen dot by means of the holographic technology, and anti-counterfeiting authentication information can be extracted in a distortionless mode when any one of printing images is cropped. The holographic anti-counterfeiting algorithm based on the shape of the screen dot has strong robustness and can ensure anti-counterfeiting security and stability.

Description

technical field [0001] The invention relates to a digital watermark anti-counterfeiting technology, in particular to a holographic anti-counterfeiting algorithm based on dot shape. Background technique [0002] The encrypted holographic digital watermark does not require the participation of the original carrier image, and the original watermark image can be extracted through the correct key. Fourier transform encrypted holographic digital watermark technology modulates the original digital watermark information through double random modulation templates, and generates Fourier transform encrypted holographic digital watermark through Fourier transform holographic technology. The watermark is resistant to attack and has strong resistance to low-pass filtering and noise , shearing and other properties. [0003] At present, the embedding and extraction steps of encrypted holographic digital watermark are as follows: [0004] (1) Generation of encrypted holographic digital wat...

AI Technical Summary

Problems solved by technology

[0008] The present invention aims at the problem that the extracted information of the encrypted digital watermark is easy to be distorted, and proposes a holographic anti-counterfeiting algorithm based on the dot shape. A piece of printed image can extract anti-counterfeiting authentication information without distortion

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