Abstract: Multipurpose watermarking, which has the property of both robust and semi-fragile watermarking, can realize two or more purposes in one algorithm, e.g. copyright protection and content authentication usually. It can be classified into multi-segment and single-segment watermark embedding. The latter is better in invisibility, but more challenging than the former. A multi-purpose image watermarking algorithm with single-segment watermark embedding for progressive transmission was proposed. It embedded a watermark abstracted from original image into middle and low-frequency coefficients of block DCT transform. In the watermark embedding process, the intensity of watermark could be dynamically adjusted according to the local texture and highlight intensity of the host image. In this way, the algorithm could fast perform copyright protection and locate spiteful tamper. The intensive experimental results show that our algorithm meets our expectation that copyright protection and locating spiteful tamper can be carried out at the same time.

Key words: multipurpose watermarking, progressive transmission, JPEG, human visual system (HVS)