Adaptive Multi-resolution Halftone Image Embedding

In the publishing and printing applications, hidden data is embedded into images for copyright protection and ownership generally. Based on the multi-resolution halftone watermarking (MRHW), adaptive multi-resolution halftone watermarking algorithm (AMRHW) is proposed in the paper. According to the characteristics of the carrier image, the pixels of the watermark halftone image are embedded into the position of the minimal impact in the carrier image, and the locations of these pixels are stored in the decoding matrix. Then, the carrier image is processed by error diffusion, and thus the watermarked image is obtained. In the watermark extraction process, according to the data of the decoding matrix, the corresponding pixels are extracted and grouped together. The watermark image is viewed directly. The results show that the AMRHW can obtain better quality of the embedding than the MRHW, while the decoding matrix can ensure great security of the watermark image.