Anti-Counterfeiting Technologies for Digital Halftone Images Based on Moire Methods

Moire effect is a special optical phenomenon caused by the interference of light. In the printing industry, it is also called Moire phenomenon which is caused by superposition of the multicolor printing dots for halftone images. Now it is widely used in the anti-counterfeiting areas. In this paper, we firstly introduce the basic principle of Moire effect. Then we describe several main applications of the Moire effect in the field of halftone image security. We review the main types of Moire-based anti-counterfeiting methods, compare them, and explain how they can be used for such security applications. It will provide the necessary technical information for the persons that in anti-counterfeiting area.