A basic principle of random texture anti-counterfeit technology is that the producer utilizes random feature distribution of texture elements formed in random process, to judge a product's authenticity via comparing whether it is conformity with stored random features, for purpose of anti-counterfeit. Currently, there is a fatal fault in random texture anti-counterfeit technology, which is unable to distinguish imitation deception of printed texture elements under condition of a recognition system. If printed texture elements (ink, hot-stamping and etc.) can imitate random textures while the imitation can not be distinguished by a recognition system, the faker can easily copy in large amount with low cost, which in turn will make anti-counterfeit effects of the random texture anti-counterfeit technology into uselessness or defeat.
Improving resolving power of a recognition system without cost considering can distinguish imitation deception of printed texture elements, but increased cost of a recognizer used in recognizing will certainly make promotion and utilization of the technology into difficulty. Texture elements on anti-counterfeit material shall be photographed by using a super-high power microscope for sampling and storing, and then compared also by using a super-high power microscope when recognizing, this manner is not only in very high cost for sampling, but also is difficult for carrying with the super-high power microscope, and contra-positioning and focusing is difficult when recognizing with a recognizer in very high cost.
In current technology, there is also a laser surface verification system; its principle is to radiate surface's textures of texture material by using a bunch of laser, diffused reflection lights with different intensities at multi-angles are sampled and stored by using several CCD receivers, when recognizing, the recognizers used in almost the same process of sampling and storing is adopted for sampling and comparing. This system has very high requirement on contra-positioning when recognizing, not only is the recognition distance required as the same as that when sampling and storing, but also the laser-radiation angle shall be the same, as well as sampling directions shall be all the same when recognition by using the laser surface verification system. When sampling and storing, any deviation may cause wrong judgment. And it has higher requirement on the laser surface verification system and shall be equipped with removable scanner, its operation is too strict to popularize, especially in area of civil goods.
Chinese patent CN1350260 “Anti-counterfeit method for random texture” involves an anti-counterfeit method that uses random structure texture element characteristic of material as an anti-counterfeit information carrier, which is difficult to repeatedly imitate by current technology; after process of scanning, recognizing and encrypting the random texture element images by computer, it forms another encrypted and converted image that is then directly printed onto the product of original random texture element images; the encrypted and converted image carries random feature information of the original random texture element images, and product's authenticity is identified via comparing two random texture element distribution images by using an independent recognizer equipped with corresponding decryption program. Said recognition system in this document does not involve any functions of preventing imitation deception of printed texture elements, which causes easily printing imitation of random features of their texture elements in low cost.
Chinese patent CN1430175 “An encryption anti-counterfeit method based on material characteristics” involves an encryption anti-counterfeit method based on material characteristics, including a signing treatment process to form anti-counterfeit information on safety protectors and a checking treatment process to recognize the anti-counterfeit information. It is designed based on a principle of “Complex random phenomenon is difficult to repeat and artificially control”; it can prevent copying and deceiving, and effectively recognize authenticity of a material. The signing process includes: in manufacturing process of paper for goods label or bill, tangible material is mixed to form randomly distributed texture element structure and to set a collection area of texture element structure images; the texture element structure is converted into image information able to be processed by computer, and image features are extracted from the image information by using image process method; the feature, allowable error of image recognition, and anti-deceiving information are used to prepare a bar code that is then printed onto bar code area; plaintext message is encrypting-processed by private key and via signature algorithm to form digital signature; the digital signature as an anti-counterfeit identification code is prepared onto the safety protectors. The checking treatment process is a contrary operation of the process mentioned above. The content of this document is the same as that in Chinese patent CN1350260, said recognition system either does not involve any functions on how to prevent imitation deception of the printed texture elements.
A key problem is to provide a simple, low-cost and easily operable recognition system that can check random features of texture element distribution, and prevent inherent features of texture elements from imitating by low-cost technique and method, especially deceiving and imitating by printed texture elements.