A new wavelet content-based watermarking technique

This paper proposes a new quality-controlled watermark embedding method. The proposed technique is based on a block classification approach in the wavelet domain, which utilizes the characteristics of the human vision system (HVS). The watermark strength and the spread of the signal into a block are controlled by block activity measurements. A block distortion index, based on the block energy (activity), is calculated as an energy measurement of the embed watermark. A classification based on this distortion index is used as a pre-processor to the watermark embedding process. Computer simulation results show the superior performance of the technique for preserving the high quality of watermarked images. The algorithm is also shown to be robust to a variety of image processing operations.