Digital Image Watermarking in Regions of Interest

Most existing watermarking techniques embed watermarks into the entire image without taking the image content into account. For many applications, a certain portion of an image is more important than the other regions, which is often called the region of interest (ROI). In this work, we develop two wavelet-based watermarking schemes which exploit both frequency- and spatial-domain information to embed invisible and robust watermark. The first scheme requires the original image and the priori information of ROI during watermark extraction. The second scheme does not require the knowledge of the original image and ROI in the retrieval process. In addition to enforcing copyright protection on digital images, the proposed interactive ROI watermarking schemes can be used as data labeling to assist content retrieval in multimedia archiving. Experimental results show that the embedded watermark is robust against various attacks with more protection on ROI.