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  • Research Article
  • Open Access

Embedding Color Watermarks in Color Images

EURASIP Journal on Advances in Signal Processing20032003:548941

  • Received: 17 May 2002
  • Published:


Robust watermarking with oblivious detection is essential to practical copyright protection of digital images. Effective exploitation of the characteristics of human visual perception to color stimuli helps to develop the watermarking scheme that fills the requirement. In this paper, an oblivious watermarking scheme that embeds color watermarks in color images is proposed. Through color gamut analysis and quantizer design, color watermarks are embedded by modifying quantization indices of color pixels without resulting in perceivable distortion. Only a small amount of information including the specification of color gamut, quantizer stepsize, and color tables is required to extract the watermark. Experimental results show that the proposed watermarking scheme is computationally simple and quite robust in face of various attacks such as cropping, low-pass filtering, white-noise addition, scaling, and JPEG compression with high compression ratios.


  • robust and transparent watermarking
  • oblivious watermark detection
  • uniform color space
  • color quantization
  • just noticeable color difference

Authors’ Affiliations

Department of Electrical Engineering, Tatung University, 40 Chungshan North Road, 3rd Section, Taipei, 104, Taiwan
Opto-Electronics & System Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan


© Copyright © 2003 Hindawi Publishing Corporation 2003