基于网点形状的半色调信息组合防伪算法

研究基于不同网点形状的半色调信息组合防伪算法,获取能实现最佳防伪效果的网点形状组合。将圆形、方形、菱形网点两两组合形成6种结合方案；对防伪信息部分作二值化处理,提供调制信号作为加网过程中网点选择的依据,获取带有隐藏信息的半色调图像；利用模板匹配法生成网点匹配模板,提取防伪信息并进行主客观评价。研究结果表明,圆形-菱形网点组合生成的半色调图像与原图更为接近,且其防伪信息的隐蔽性好,提取的防伪信息与原信息的结构相似度较高。网点形状组合的择优选取保障了图像信息的准确再现,并提高了防伪性能。

Combined Halftone Information Anti-counterfeit Algorithm Based on Dot Shape

In order to study the halftone anti-counterfeit algorithm based on different dot shape and obtain different printing dot combination which can achieve the best anti-fake effect,experiment selected circular,square and rhombus dot shape to form six combination schemes.Then the anti-counterfeit information was binarized to be the modulation signal as the basis of dot shape selection in the process of halftone,thus acquiring the halftone image with hidden information. Template matching method was used to generate dot matching template to extract the anti-counterfeit information,and achieved subjective and objective evaluation of the information.The results showed that halftone image generated by the round-diamond dot shape combination was closer to original image,and its anti-counterfeiting information had better concealment.Besides,extracted information was highly similar to original information.The selection of dot shape combination ensures the accurate reproduction of image and provides better anti-counterfeiting performance.