A Comprehensive Survey on Digital Image Watermarking Techniques

Image watermarking is gaining more popularity due to the wide use of internet and multimedia applications. Image watermarking adds additional information about host image in the form of logo/audio/video or text. Main aim of watermarking is to provide copyright protection, Content authentication, Ownership identification, data integrity. Watermarking does not only protect content from modification only but also provide data integrity and content authentication. Main requirements of watermarking are high imperceptibility, Strong robustness, security, capacity that varies according to different application. Techniques in spatial domain are simple, have lower complexity and can embed more number of bits but they are not resistant to some geometric attacks. While techniques in frequency transform domain are resistant to both geometric and image processing attacks but when frequency is corrupted robustness decreases and cannot embed more number of bits because quality gets degraded. These techniques cannot embed more bits as it degrades the quality of host image. So these techniques must be used with other techniques of spatial domain which has high capacity.