The hiding of digital watermarks has been an interesting problem for many researchers
in recent years. Although many watermarking techniques were proposed successfully to
deal with both bi-level and gray-level watermarks, it is necessary to develop a robust
watermarking method for the color watermarks.
The purpose of this proposal is to develop a frequency-domain-based watermarking
method in which the color watermarks can be treated. In the proposed method, the YUV
color system is first combined with the discrete cosine transformation, and then the color
images in the time domain are transformed into the frequency domain. After the proper
treatment, the frequency coefficients of the color watermarks are hidden into the
middle-low- frequency coefficients of the color images. In the hiding process, the
robustness of the middle-low- frequency is developed into a favorable property to resist the
ravages of various image processing. Finally, a series of experiments will be conducted to
verify the practical efficacy of our purpose.