Digital Image Watermarking Scheme using Adaptive Block Division

  • Cho, Soo-Hyung (School of Electronic and Electrical Engineering, Kyungpook National University) ;
  • Jung, Tae-Yeon (School of Electronic and Electrical Engineering, Kyungpook National University) ;
  • Joung, Young-Hoon (School of Electronic and Electrical Engineering, Kyungpook National University) ;
  • Lee, Kyeong-Hwan (Department of Multimedia Engineering, Uiduk University) ;
  • Kim, Duk-Gyoo (School of Electronic and Electrical Engineering, Kyungpook National University)
  • Published : 2002.07.01

Abstract

Digital image watermarking scheme using adaptive block division is proposed. To increase the perceptual invisibility, the image is divided into blocks by local properties and the human visual system (HVS), then the significant blocks are selected in the divided blocks. The significant coefficient is determined by Weber's law in these blocks. To increase the robustness, low frequency domains of the discrete cosine transform (DCT) and the discrete wavelet transform (DWT) are used. The watermark is embedded into the selected significant blocks of the DCT's and DWT's low frequency domains with adaptive watermark strengths. The watermark strength is determined by the variance and the local properties of the significant block. The experimental results prove that the proposed scheme has a good robustness against several image processing operations (e.g. median filtering, cropping, scaling, JPEG, JPEG2000, etc.) without significant degradation of the watermarked image.

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