QIM DATA HIDING FOR TAMPER DETECTION AND CORRECTION IN DIGITAL IMAGES USING WAVELET TRANSFORM

This paper proposes a tamper detection and correction scheme using semi-fragile data hiding that aims to achieve high perceptual quality of images at the end-user even after malicious modification. The objective is achieved by embedding an external binary signature as well a low-resolution version of the image (image digest) by modulating integer wavelet coefficients using quantization index modulation (QIM). Half-toning technique is used to obtain image digest from the low-resolution version of the image. The receiver extracts the binary signature from the watermarked image for tamper detection while the extracted image digest is used to correct the tampered region. Unlike previously proposed techniques, this novel approach distinguishes malicious changes from various common image processing operations more efficiently and also correct tapered regions effectively. We compare the performance of the proposed method in term of probability of miss and false alarm with the same for the some of the existing semi-fragile watermarking techniques to demonstrate the success and potential of the present one.