Colour spaces effects on improved discrete wavelet transform‐based digital image watermarking using Arnold transform map

The most digital image watermarking algorithms have nearly always been realised in red, green and blue (RGB) colour space. In this study, a secure, robust and imperceptible CDMA image watermarking scheme which uses discrete wavelet transform is proposed and tested in eight colour spaces RGB, YCbCr, JPEG‐YCbCr, YIQ, YUV, hue, saturation, intensity, hue, saturation, value and CIELab to determine which colour space is more effective in watermarking algorithms based on correlation techniques and provides a result which does not differ immeasurably from the original with respect to imperceptibility and robustness. In the proposed scheme, a scrambled binary image by Arnold transform map, after encryption, is embedded into sub‐images of the first channel wavelet decomposition of intended colour space using block processing technique. The experimental results show that the proposed approach provides extra imperceptibility, security and robustness against JPEG compression and different noise attacks compared to the similar proposed methods in earlier works.