In this paper we propose a content based multibit watermarking method robust to print–scan
attack. A method to extract feature points, robust in terms of watermarking, is proposed. The
location of the watermark is tied to a coordinate system defined by robust feature points. A
message sequence is mapped to a directional angle of periodic patterns, which are
scattered and embedded into triangles in permuted locations. In watermark extraction, an
interplay between feature extraction and watermarking ensures reliability and a multibit …