Research On New Technology Of Forgery Detection For Printed Materials

In this paper, the applications of Machine-Readable labels and photo watermarking technique in anti-counterfeit of presswork are lucubrated. The paper's main contents are given as following:1. Anti-damaging two-dimensional barcode is designed and accomplished based on the principle of optical Fourier Transform and multilevel recording. It has been proved with anti-damaging and practicability of Machine-Readable multilevel 2D barcode. It has been indicated that information in barcode can be detected accurately with the algorithm proposed in this paper given the damaged part taking up over 30% of the total proportion.2. The fading effect of 2D color barcodes is analyzed with the Ultraviolet Ageing Test. A barcodes detection method of self-adaptive threshold is presented based on RGB model and the principle of probability and statistics. It has been indicated that the self-adaptive threshold method is able to correct the color fading effectively and reduce the error rate of the faded label to 0.05 percent (25 hours Ultraviolet Ageing Test).3. With the platform of Matlab, three kinds of algorithms which are anti-printing and anti–scanning effectively are being validated. The advantages and problems existed of different algorithm used in ID photos are analyzed and compared. Taking advantage of three algorithms given above in withstanding scanning and printing influence, a digital watermarking algorithm based on coefficients of intermediate frequency Discrete Fourier Transform is proposed. It has been proved in the experiment that much more digital information can be embedded in small areas and the requirement for certificates Anti-counterfeiting is satisfied in withstanding scanning and printing influence.Compared with the method of forgery detection of printed image, the advantages of highly safe, low cost and easy to carry out are provided with the certificates anti-counterfeiting technique based on the combination of Machine-Readable two-dimensional barcode and ID photo watermark.