Blind and robust watermarking scheme combining bimodal distribution structure with iterative selection method

Abstract

To protect the ownership, a blind and robust watermarking scheme is devised by the coefficients of the discrete cosine transform. In the embedding process, the absolute differences of discrete cosine transform coefficients are divided into two groups according to the watermark. That’s to say, the shape of the absolute difference histogram is modulated to build a bimodal structure. In the extraction process, an adaptive threshold is calculated with an iterative selection method. To our knowledge, it is the first time to take advantage of the robust characteristic in a particular shape. Besides, several attack experiments including JPEG compression, cropping, resizing and blurring are performed. The results in attack experiments and comparison experiments demonstrate the superiority of the proposed blind watermarking scheme.