Region based QIM digital watermarking scheme for image database in DCT domain

This paper proposes a region based digital watermarking scheme to serve the purpose of copyright protection and integrity verification of image database using discrete cosine transform (DCT). The objective is achieved by embedding watermark into visually significant regions of the image(s) using quantization index modulation (QIM). The main contributions of this work are, (1) the use of quad tree decomposition for image segmentation to find visually significant regions, and (2) the use of image database as a single entity for watermarking, instead of watermarking on individual image, so that integrity of the database is checked. Simulation results validate the above claims. Simulation results also show that the proposed scheme is robust and secured against a wide range of attacks available in StirMark 4.0 package. (C) 2011 Elsevier Ltd. All rights reserved.