Research on adaptive digital watermarking based on spread spectrum
Quan Li, Xuemei Jiang, Namin Yu · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2003
In this paper, the direct-sequence spread-spectrum technique is introduced to spread watermark signal. Then by utilizing a just noticed difference threshold in spatial domain based on visual masking effect of human visual system, watermarks strength and the embedded locations can be controlled in imagae adaptively. It was shown with experiments that the digital watermark not only can guarantee the transparency, but also has good robustness to JPEG compression, median filter, sub-sampling, etc.