Method for carrying out image-text hiding according to encrypted and converted phase position

Abstract

The invention discloses a method for carrying out image-text hiding according to an encrypted and converted phase position. The method includes the following steps: a Fresnel diffraction converting method is adopted to carry out encryption and conversion on an image-text to be hidden, so as to obtain a black-and-white stripe pattern namely a phase information pattern which is composed by the encrypted and converted phase position; on the basis of the phase information pattern, the image-text to be hidden is respectively hidden in an encoding card and a decoding card; when the encoding card and the decoding card are overlapped and aligned with each other, the hidden image-text can reappear. As the pattern of image-text information hidden in the cards is stripe-shaped, the overlapping and aligning operations of the encoding card and the decoding card can be easily realized when in reappearing; moreover, as different image-texts have different stripe shapes, the counterfeiting difficulty is enhanced and the anti-counterfeiting strength is enhanced as well. As the image-text information hidden on the decoding card or the encoding card presents the form of grating stripes of the phase information pattern, the effect of optical diffraction is achieved and the image-text hidden on the decoding card and the encoding card can reappear by laser. Anti-counterfeiting logos manufactured by the method for the two cards cannot be easily counterfeited, and the anti-counterfeiting strength is greatly enhanced.

Description

technical field [0001] The invention belongs to the anti-counterfeiting technology, and in particular relates to a method for hiding pictures and texts according to the encrypted transformation phase, which can be used for double-card anti-counterfeiting marks. The encoding and decoding cards have part of the image and text information that is hidden according to the phase of the encrypted transformation, and the overlap and alignment of the decoding card and the encoding card can clearly reproduce the hidden image and text. Background technique [0002] The traditional dual-card anti-counterfeiting mark uses the optical Moiré principle, that is, the principle that the overlapping of stripes of two periodic structures can produce a third periodic structure. In one of the periodic stripes, its phase is changed and a pattern is encoded. The pattern is hidden and cannot be discerned at ordinary times, and the pattern appears when it overlaps with another periodic stripe. This ...

AI Technical Summary

Problems solved by technology

This method is easy to imitate because the modulation of the stripes is relatively simple, and the anti-counterfeiting strength is low.

[0003] There is a randomly distributed encrypted image double-card anti-counterfeiting mark, the pattern of the hidden image information on the decoding card and the encoding card is a dot pattern, and it is difficult to align the decoding card and the encoding card during the reproduction operation

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