Multimedia Security

4	Automatic Detection and Removal of Visible Image Watermarks
Hong-Ren Su, Ya-Yun Cheng and Shin’ichi Lai

CONTENTS

4.1    Introduction

4.2    Visible Image Watermark

4.2.1    Watermark Embedding

4.2.2    Watermark Removal

4.3    Fourier-Based Image Registration

4.3.1    Rigid Transform Relationship Between Image and Fourier Domain

4.3.2    Moment Matching Approach to Estimating Rigid Transform Matrix

4.3.3    A Novel Fourier-Moment-Based Image Registration Algorithm

4.4    Iterative Refinement Process by a Distance Weighting

4.4.1    Binary Edge Image Data

4.4.2    Distance Weighting

4.4.3    Fourier-Based Image Registration Algorithm with Iterative Refinement

4.5    Visible Watermark Removal

4.5.1    Watermark Removal for Pictures