Recovery of Watermarked Image from Geometrics Attacks using Effective Histogram Shape based Index
Mitta Divya, Murari Devakannan Kamalesh · Indian Journal of Science and Technology · 2016
Objective: The main objective of the paper is to provide security and proof of ownership to the watermarked image. Methods: Watermark is a transparent or an undetectable signature implanted inside an image to show uniqueness or proof of ownership. The illegally used images can undergo different kind of attacks namely signal processing attacks and geometric attacks. We have used Tree Based Parity Check (TBPC) algorithm to deal with these common attacks. We preprocess the host image using Gaussian filter. And using Fast Walsh-Hadamard method, we embed watermark inside an Image. Findings: We choose the Gray levels of the image by the means of secret key. Later we construct the histogram based on the gray level that is chosen. In these chosen pixels group’s watermarks are embedded. Then a secret text or code is inserted into this filtered image. To encrypt this text we use Tree Based Parity Check algorithm. Based on the secret key that is available, in the decoding phase we identify watermark pixel group and then we extract the watermarks from them. Application: The proposed system can achieve strong robustness of the image and detailed view of Bone structure in X-ray images. It can also be used to find the duplicate currency notes. Keywords: Fast Walsh-Hadamard and Tree Based Parity Check, Gaussian Filter, Image Water Marking