Brandon Migdal May 7 th 2004 Rochester Institute of Technology Advisor: Dr. Carl Salvaggio Watermark Extraction Methods For Linearly Distorted Images to Maximize Signal-to-Noise Ratio Brandon Migdal May 7 th 2004 Rochester Institute of Technology Advisor: Dr. Carl Salvaggio

Outline  Embedding Process  Research  Extraction Process  Results  Future Work

Embedding Process Carrier Message … FFT Multiplication Inverse FFT Scale Amplitude Zero Mean Initial Image FFT +

Template Design  Considerations  Location Design  Reasons

Template

Template

Template

Embedding Process Carrier Message … FFT Multiplication Inverse FFT Scale Amplitude Zero Mean Initial Image FFT +

Carrier

Carrier Design  Random Phase  Generated Pseudo-Random  Scale based on Nyquist, and CSF  Reasons

Embedded Image

Distortion

Research Areas  Windowing  Subsetting

Windowing FFT Windowing Technique Substitute Into Level 3 Extraction Process

Subsetting Subset Level 3 Extraction Process +

Embedded Image Level 3 Extraction FFT Cross Correlation FFT -1 Blurring Filter SNR Extraction Level 2 Extraction Comparison Image Information Level 1 Extraction Image Information & SNR Scaling Factor X + Scaling Factor X Divided by Total Number of Image Blocks For All Image Blocks Average Image Block FFT Cross Correlation Binary Message

Results

Results

Results

Results

Future Work  Windowing  Subsetting

Reference Material  Gonzalez, R., and R. Woods, Digital Image Processing, Second Edition, 2002, New Jersey: Prentice Hall  Rabbani, M., and C. Honsinger, Data Embedding Using Phase Dispersion, IEE Seminar on Secure Images and Image Authentication Ref. No.00/039, 2000, Volume 5, pp. 1-7  Xie, H. N. Hicksa, G. Kellera, H. Huangb, and V. Kreinovich, An IDL/ENVI implementation of the FFTbased algorithm for automatic image registration, Computers & Geosciences, 2003, Volume 29, pp. 1045–1055  Signal-to-Noise Calculations, January 2004, _lectureCW/SEM_SignalNoise.html

Questions?