Self Embedding Watermarking Using Halftoning Technique

This paper proposes a self-embedding watermarking scheme for digital images. It exploits a digital halftoning technique to transform the host image to a halftone image, in which the content features of the host image are well preserved. This halftone image is utilized as an approximate or compressed version of the host image and further adopted as a watermark. Unlike most available self-embedding watermarking techniques, in which watermark embedding, tamper detection and image recovery are block-wise-based, our scheme is a pixel-wise and block-wise composite scheme. That is, the watermark is pixel-wise permuted and embedded in the least-significant-bit plane of the host image, while in tamper detection and image recovery, a block-wise strategy is employed. This pixel-wise and block-wise complementary mechanism can overcome a common disadvantage of previous block-wise-based self-embedding watermarking techniques. Our scheme can be used for tamper detection and alteration location. Moreover, the tampered area can be approximately recovered using the extracted watermark. Experimental results demonstrate the effectiveness of the proposed scheme.