Transform Based Digital Image Watermarking Techniques for Image Authentication

In the past few years many new techniques and concepts based on data hiding have been introduced for image authentication and copy right protection. With a lot of information available on various search engines, to protect the ownership of information is a crucial area of research. Digital watermarking is a popular technique that is used for copyright protection and authentication. Digital watermarking is hiding the information inside a digital media. This paper attempts to first introduce general idea behind digital watermarking as well as some of its basic characteristics followed by describing some applications of watermarking techniques. In spatial domain, LeastSignificant Bit (LSB), Patchwork algorithm and Texture mapping coding method and in the transform domain, Discrete Fourier Transform (DFT), Discrete Cosine Transform (DCT), Discrete Wavelet Transform (DWT) has been discussed. In this paper it can be proposed frequency domain watermarking using DCT and watermark is embedded in the Mid Frequency Band of DCT. Keywords— watermarking, authentication, copy right protection, (LSB), Discrete Cosine Transform, Discrete Wavelet Transform.