WATERMARKING FOR STILL IMAGES

Abstract

The need for electronic watermarking development as an electronic distribution of copyright material becomes prevalent. This watermarking technique has been more popularly used for electronic copyright protection. Best encryption and decryption algorithms have been used for security and authentication purpose, but watermarking technique with encryption and decryption provides an additional robustness. Watermarking technique should be considered as a communication problem in which a signal carrying some information is transmitted through a noisy channel, where the noise is the original image itself, unknown to the receiver. Watermark verification can be seen as a statistical decision problem, firstly to detect the very presence of the watermark, and then estimate the information it can optimally carry. In this dissertation work the study of watermark insertion algorithms, the performance of adaptive wiener filter for the watermark information, and its performance for various watermarked images with different pulse amplitudes and various attacks have been considered. This filter is used to estimate the original image from watermarked image, which is considered to be as noise in statistical analysis to determine probability of detection and probability of false alarm. iii