Image watermark retrieval based on majority voting from different color spaces
Thitiporn Pramoun, Narong Mettripun, Thumrongrat Amornraksa · 2011
In this paper, a new watermark retrieval method is proposed to be used in the digital watermarking based on the modification of image pixels in order to improve the accuracy of the retrieval watermark and simultaneously enhance the robustness of the embedded watermark. Conceptually, different color spaces usually display different discriminating energy. The watermark embedded in blue component of RGB color space can thus be retrieved from other components in different color spaces i.e. YCbCr and YIQ. Since the quality of watermark in blue components is sometimes better and worse than the one dispersed to the components in different color spaces, majority voting from three different color spaces is used to decide the true value of retrieved watermark bit. The experimental results on a set of standard testing images show the improved accuracy of the retrieved watermark compared to the watermarking scheme with the existing retrieval method. The enhanced robustness of the embedded watermark against various attacks is also evaluated and compared.