Digital Signal Processing Final Project Proposal R 資工碩一 馬智釗 Reference : “Rotation, scale, and translation resilient digital watermarking based on complex exponential function”, S. Pholsomboon, S. Vongpradhip

Digital Watermarking Embed information about copyright or ownership without introducing of visible change on digital media. Embed information about copyright or ownership without introducing of visible change on digital media. - protect multimedia data from piracy. A robust digital watermark must be recognizable although the embedded media have been transformed. A robust digital watermark must be recognizable although the embedded media have been transformed. - cropping, blurring, JPEG compression. - geometrically transformation (RST)

Spread Spectrum Use DFT to transform an image, and add watermark on frequency domain. Use DFT to transform an image, and add watermark on frequency domain.

Proposed Watermark Circular-shaped. Circular-shaped. Fixed frequency, Fixed frequency, random phase. Each ring’s phase Each ring’s phase represent the code of watermark.

Watermark Embedding The watermarked image is obtained by applying IDFT on frequency domain. The watermarked image is obtained by applying IDFT on frequency domain.

Robustness Invariant to rotation and translation. Invariant to rotation and translation. Resilient to scaling. Resilient to scaling. - based on properties of Fourier transformation Watermark can be detected after performing other transformation. Watermark can be detected after performing other transformation. - JPEG compression - printing and scanning - watermark counterfeiting (random seeds)