Image Authentication Using Digital Watermarking

Watermarking is a technology used to embed some kind of information inside a digital content (text, image, audio or video) using different techniques. The embedded information depends upon the application. Watermark should be robust and imperceptible. Robustness of watermark can be explained in terms of successful recovery of watermark from recovered content which may contain different types of noises and compression effects. After recovering the watermark, the recovered and original watermarks are compared by calculating of similarity factor (SMF) of these two watermarks. If the similarity factor is closer to one than we can conclude that the content is original and/or authenticated. This paper entails the study of watermarking technique and delve deeper to improve the robustness of the image. To achieve this, a detailed insight is provided into few techniques explaining each one as a comprehensive step by step procedure and calculating SMF and Peak signal to Noise ratio (PSNR) for different samples considering various attacks.