Kallol Bhattacharya

Abstract: Development of computer networking generates many benefits in cyber world. Due to this great advancement, nowadays networking facilities are available at very low cost. But unfortunately this easy access becomes a threat to information security. Watermarking is a technique that is very often used in image processing to trace copyrighted products. It can also be used to trace products which are illegally distributed without permission. In our research work, a new technique for invisible watermarking of images using alpha blending has been proposed. Alpha blending is used to display an alpha bitmap and an alpha bitmap is that one which has transparent and semi-transparent pixels. We have worked on color image and gray scale image. Gray scale image is used as watermark image which is kept hidden in the main scale image by different values of alpha in alpha blending method. This technique is actually done on each plane of the color image. The resulting image contains the information of color image and gray scale images but the main image is unseen to others. PSNR values are also calculated to check the robustness of the reconstructed image. Applying some post-processing work, this can be used in image steganography also.

Abstract: Hiding data in an image become a very successful technique to communicate with end users, blinding the interpreter’s intention. Various algorithms have been analyzed on the basis of masking the content within the coordinates of the images or in the color of the images used. Few advanced developed complex algorithms to hide the content in the values of the colors to ensure or guarantee robustness of the data hidden. In this research, a simple technique called alpha blending is used to hide the data in an image and its impact is analyzed for different alpha values. The unavoidable impact of noise on the transmitted carrier image was formulated and studied by many researchers using various available algorithms. In this regard: the same is analyzed using alpha blending in thermal images.