Multi-channel data hiding scheme for color images

This paper presents a new watermarking technique in the spatial domain expressly devised for color images, which is based on transmit diversity techniques. The RGB tones of color images are considered as three independent slowly fading channels. Modulated by different pseudo-random sequences and interleavers, the same watermark in different forms is put into three color channels simultaneously. This scenario makes up the weakness in single color channel schemes that a single color channel is prone to severe fading. HVS characteristics of the three color channels are separately considered. We use two extraction methods: one is by comparing the energy strength of the three channels, the other is by accumulating the energy of three channels. Experimental results demonstrate the unmistakable advantage of our new approach over algorithms operating on single color channels. In contrast to the present spatial watermarking schemes, this algorithm is considerably robust to many intentional and unintentional attacks.