Geometric Invariant Digital Image Watermarking Scheme Based on Feature Points Detector and Histogram Distribution

A robust and geometric invariant digital image watermarking scheme based on SIFT Based Feature Points Detector (SIFT_FPD) and histogram distribution is proposed in this paper. The SIFT_FPD is proposed to extract geometric invariant feature points from the host image for watermark embedding; and the descriptor is generated subsequently. With the feature extraction procedure, the circular regions centered at the extracted feature points and with the given radius are defined as embedding regions. For watermark embedding, some pixels are moved to form a specific pattern in the intensity-level histogram distribution in each embedding region, to indicate the watermark. For watermark extraction, the embedded regions are generated with the descriptor and according to the intensity-level histogram distribution in each region, the watermark can be extracted. Experimental results show that the proposed scheme is very robust against geometric distortion such as rotation, scaling, cropping, and affine transformation; and common signal processing, such as JPEG compression, median filtering, and Gaussian low-pass filtering.