الفهرس | Only 14 pages are availabe for public view |
Abstract Today manipulation of multimedia (digital images or videos) has become easy due to powerful computers, advanced photo-editing software packages and high resolution capturing devices. Verifying the integrity of images and detecting traces of tampering without requiring extra prior knowledge of the image content or any embedded watermarks is an important research field. This dissertation aimed to detect the forgery in images to achieve the integrity in digital images. We introduce two techniques to detect the tampering in digital images as follows: - Investigating several techniques based on different types of Polar Harmonic Transforms (PHTs in order to evaluate the effect of transform domains in the quality of tampering detection. The good performance is in favor of Polar Sine Transform (PST)-based tamper detection method. - A hybrid robust technique for digital watermarking algorithm based on Singular Value Decomposition (SVD), integer discrete cosine transforms (Integer DCT) and chaotic 2-dimensional system is proposed. Experiments conducted show that the embedded watermarking image survives most of the common image processing attacks and geometric distortions as noise addition, JPEG compression, histogram equalization, scaling, filtering, rotation (rotating 90º, 180 º, and 270 º), etc. |