A Robust Multiple Watermarking Scheme for Still Image using DWT, DCT and Spread Spectrum.

Wen-Yuan Chen Chin-Hsing Chen Jzau-Sheng Lin A Robust Multiple Watermarking Scheme for Still Image using DWT, DCT and Spread Spectrum. 668-671 2002 conf/jcis/2002 JCIS db/conf/jcis/jcis2002.html#ChenCL02