A Novel Technique to Encrypt the Digital Image Based On Hybrid DCT And DWT And Bilateral Smoothing

In image Steganography the information is hidden exclusively in images. Steganography is the art and science of secret communication. It is the practice of encoding/embedding secret information in a manner such that the existence of the information is invisible. Steganalysis is the breaking of Steganography and is the science of detecting hidden information. The main objective of steganalysis is to break Steganography and the detection of stego image. Almost all steganalysis algorithms depend on Steganography algorithms introducing statistical differences between cover and stego image. Similar techniques can also realize large-capacity embedding for Steganography. Candidate transforms include discrete cosine Transform (DCT), discrete wavelet transform (DWT), and discrete Fourier transform (DFT). By being embedded in the transform domain, the hidden data resides in more robust areas, spread across the entire image, and provides better resistance against signal processing. The Work is carried out with the objectives to find out the best image Steganography method among the Discrete Cosine Transform, Discrete Wavelet Transform, Hybrid Transform and Novel Transform method with application of bilateral smoothing for denoising purpose on the basis of its factors like Peak Signal to Noise Ratio, Mean Square Error, Normalized Absolute Error and Correlation .The primary objective of my current work is to increase PSNR and decrease MSE and NAE of the image.