<title>Adaptive color watermarking</title>

Abstract

In digital watermarking, a major aim is to insert the maximum possible watermark signal while minimizing visibility. Many watermarking systems embed data in the luminance channel to ensure watermark survival through operations such as grayscale conversion. For these systems, one method of reducing visibility is for the luminance changes due to the watermark signal to be inserted into the colors least visible to the human visual system, while minimizing the changes in the image hue. In this paper, we develop a system that takes advantage of the low sensitivity of the human visual system to high frequency changes along the yellow-blue axis, to place most of the watermark in the yellow component of the image. We also describe how watermark detection can potentially be enhanced, by using a priori knowledge of this embedding system to intelligently examine possible watermarked images.

An Overview of Digital Video Watermarking

“…On the other hand, most techniques [63]- [70] consider the Y in the YUV color space as the watermark embedding channel. Although a watermark is embedded in the Y channel to survive color to grayscale conversion [71], recent applications have been extended to color from grayscale images or videos. As the Y channel typically contains more bits than the U channel, it may be able to accommodate a larger watermark.…”

Watermarking and Authentication of Color Images Based on Segmentation of the <italic>xyZ</italic> Color Space

“…One limit of such methods is that they embed only one dimensional color component. Thus, Kutter[11] embeds the blue component into the spatial domain, Voyatzis [22] embeds the intensity component with a binary logo into the spatial domain, Kim [9] embeds the saturation component into the spatial domain, Fleet [7] embeds the yellow-blue component into the frequency domain, Reed [15] embeds the yellow-blue component into the frequency domain, and Kundur [10] embeds the salient image components with a logo into the frequency domain.…”

“…The methods which embed color data either into the spatial domain or into the frequency domain are generally well-adapted to increase the robustness of the watermarking process [24,16,1,21] but are not well-adapted to optimize both the invisibility (imperceptibility) of the watermark and the detection probability. For example, instead of taking advantage, only of the low sensitivity of the human visual system to high frequency changes along yellow-blue axis [2,15], we strongly believe that it is more important to focuss on the low sensitivity of the human visual system to perceive small color changes whatever the hue of the color considered [8].…”

Quaternion image watermarking using the spatio-chromatic fourier coefficients analysis

“…We will demonstrate that considerable simplifications can be made to (3) and (4), and an interpretation of the QFT coefficients can be drawn if we assign the parameters a 1 …”

“…al. proposed a system that takes advantage of the low sensitivity of the human visual system to high frequency changes along the yellow-blue axis, to place most of the watermark in the yellow component of the image [3]. Bas et.…”