Watermarking technique to enhance image security in cloud computing

With the rapid growth of internet, the various digital methods have been proposed to protect the multimedia information from the non-authorized accesses use and change. Among all the proposed methods the watermarking technique is the most common technique for protecting the multimedia data for unauthorized access. A novel method is proposed which deals with secure extraction of data by utilizing transform-based image watermarking techniques. The image is embedded with a watermark using a combination of Discrete Cosine Transform (DCT), Discrete Fourier Transform (DFT) and Discrete Wavelet Transform (DWT) in this scheme. The conventional transforms are applied in an optimized mode in these schemes in different spatial regions of the image to embed a watermark. The scheme is subjected to Signal processing attacks and Geometric attack to test against the robustness of the image. The watermarking of image is made secure by testing against unauthorized detection techniques employed by attackers. This is realized by a correlation-based detector applied to the scheme. Experimental results show that the watermarked image is robust and secure against Signal Processing attacks, Geometric attacks and unauthorized Detection attacks. The water marking methods have been categorized as spatial domain method and frequency domain method. In spatial domain method we modify the lower order bits of cover image to embed the water mark. To embed the water mark in the image simply changes the coefficient value of these transforms according to the watermark and the inverse transform is applied to the original image. These methods are too complicated and require more computational power. These methods are also provides more reverts to the security attacks. The method is GLCM technique.