Abstract: In this paper, hybrid approach is introduced where a process known as ‘watermark’ is enabled to mark digital pictures with undetectable secrete information that are invisible by using principal component analysis and discrete wavelet transform to provide a complete copyright protection system. The concept of key dependent basis function and its application is introduced to secure robust watermarking for copyright protection and to design a secure public black-box watermark detectors which shows high imperceptibility and performance where no noticeable difference is seen between watermarked and original image.