Affine Resistant Digital Image Watermarking Based on Template Matching

This paper proposes an affine-resistant digital image watermarking based on template matching.First,the message to be embedded is coded by using RS codes to enhance the resistance capability of noise.Watermark is embedded on the mid-frequency spectrum,and the positions are considered in a rectangle which is symmetric to one side of the Cross,while the specific embedded positions are determined by a one-way hash function. Two structural template lines are then added in the polar coordinate system for detecting any combination of the geometrical distortions.The detection and extraction is based on correlation between the embedded and recovered watermarks.The experimental results indicate that this technique has a good performance when undergoing geometrical attacks and JPEG compression.