A Digital Watermarking Algorithm for Anti-counterfeit in Printed Image

For inserting a digital watermarking into digital image and distilling it out exactly, the paper proposes a new algorithm of the watermarking. The algorithm of inserting and extracting digital watermarking aims at the DCT (Discrete Cosine Transform) modulus after quantization. The places of inserting watermarking are decided by the anchor points and the way of inserting watermarking is decided by the algorithm. By judge the robust of the digital watermarking, it displays the algorithm has a preferably practicability in anti-counterfeit in printed image.