Indian Journal of Science and Technology

Abstract

Digital images are widely used and can be easily altered through the internet medium. Therefore, this article proposes a novel method of fragile watermarking to detect the image tampers. The proposed method is implemented by an edge image and chaotic Arnold map. The idea of edge detection is to make the image as a binary version and also significantly decrease the sum of information in an image and conserving the structural properties. The edge image is obtained from the watermark image using the Canny edge detection operator. The security and sensitivity of the proposed method is enhanced by employing the Arnold map before embedding the edge image. The accuracy of tamper detection depends upon the variations made in the image and it highlights a location where the tamper has been done. The quality of the watermarked image is evaluated using the metrics Peak Signal to Noise Ratio (PSNR) and Normalized Correlation (NC). The experiments were carried out to assess the performance of the proposed method for several forms of fiddling with different images. The result shows that the proposed method efficiently localizes the tampered regions. 

Keywords: Fragile Watermarking, Tamper Detection, Chaotic Map, Edge Image, PSNR, NC