A watermarking technique based on JPEG quantization table

Abstract

JPEG compression is a common processing when sending an image via the Internet, thus how to protect the ownership of an image after JPEG compression is a very important issue. In this paper, we propose a watermarking scheme which has a good capacity and imperceptibility and especially robust to the JPEG compression. First the host image is divided into 8 x 8 blocks and candidate blocks are determined based on the number of edge point of ± 45º lines. By observing the standard JPEG quantization table, pairs of positions with same quantization scale are chosen for candidate blocks of the host image for embedding the watermark information. The proposed method is also extended to the video watermarking. The experimental results show our method is robust against many kinds of general attacks, especially JPEG and MPEG compression, and the performance of imperceptibility is equally well.