Watermarking Based on Balanced Incomplete Block Designs

Abstract

Watermarking is a digital rights protection approach capable of associating information about media within the digital content during the whole lifetime of the contents. Representing messages by watermarks is the first essential stage for watermarking. In previous works, watermarks are generally designed by directly encoding messages into vectors. When more than one bit of information should be embedded, it is time consuming to identify a correct watermark in a large set of possible ones. In this work, a mathematical structure called balanced incomplete block designs (BIBD) is introduced to achieve watermark design. The purposes are to generate non-orthogonal vectors based on a smaller set of orthogonal ones and to reduce search time at the stage of watermark detection. Experimental results on real images are given to show the feasibility of the method, and discussions on future works are made.