Enhanced images watermarking based on amplitude modulation

摘要

This paper presents an image watermarking method with blind detection based on amplitude modulation. Basically, the watermark embedding is performed by modifying the pixel values in the blue channel of an image, while the watermark retrieval is achieved by using a prediction technique based on a linear combination of nearby pixel values around the embedded pixels. Based on the analysis results, three different methods are proposed to enhance the watermark retrieval performance, i.e. by balancing watermark bits around the embedding pixels, by properly tuning the strength of embedding watermark, by modifying the method of pixel prediction. Experimental results show that the watermarking scheme implementing our methods achieves significant improvements over the existing schemes. Remarkable improvements are still obtained even if various types of attacks are applied.