Watermarking Algorithm for Color Images Based on Quaternion Frequency Modulation
Desheng Fu · 2011
Separate channel techniques performed on color images have the disadvantage of less ability to show connection between each channel during image processing.A new method to process color images with quaternion Fourier transform was put forward in this paper.Firstly,ununiformity of each unit quaternion block in host image was calcula-ted to pick up the potential block adaptively.Secondly,frequency matrix of host color image was obtained by using quaternion Fourier transforms.After that,the water marks were embedded into the amplitude of AC coefficient.Experimental results show that the image distortions from the watermark are spread into the three channels of a color host image and the proposed watermarking algorithm realizes a better trade off between imperceptibility and robustness.