Due to expeditious use of multimedia entities in the network, there is issue to protect images from piracy. So this is required for implementation of copyright on high priority that can preserve ownership for copyright protection and protected images can be claimed by actual owner only. Digital image watermarking is the technology invented for securing images from illicit utilize. There are many watermarking techniques in spatial as well as in frequency domain like Discrete Wavelet Transform and Discrete Cosine Transform. These techniques are widely known to be more usual, robust and imperceptible. In the paper, literature review work give out about analysis of different attacks like Gaussian Blur, Salt & Pepper, Gaussian Noise, Geometric and Joint attacks on images. Also these are implemented on DWT and DCT watermarked image using Python code and after attack the performances are measured by Peak Signal to Noise Ratio(PSNR) and Normalized Correlation(NC) for surveying about robustness of images before and after attack.

Keywords : Peak Signal to Noise Ratio, Discrete Wavelet Transform, Discrete Cosine Transform