Color image-adaptive watermarking

A novel scheme for the watermarking of colour images is presented in this communication. The first objective is to find the most suitable alternative to RGB color space, which is highly correlated. Colour spaces with linear relation to RGB colour space with uncorrelated components are found to be most suitable for watermarking applications. Second objective is to make the scheme adaptive to oˆc$80a˚ colour image. This is achieved by keeping the PSNR in a predefined quality range, while timing the watermark strength parameter. Watermark detection is fast and blind, i.e. only the watermark generation and coefficient randomization keys are needed, and not the original image. The presented results demonstrate the robustness of the method against some common image processing attacks such as compression, scaling, uniform or gaussian noise addition, median filtering, cropping and multiple watermarking.