Image Authentication Using Subband Coding

Abstract

In this paper, an image accreditation technique by embedding digital watermark into image is proposed. The proposed method for the digital watermarking is based on the context-based wavelet transform. First, unlike most of previous works which uses a random number of a sequence of bits, and can only be detected by employing the detecting methods. An experimental threshold is chosen and compared to determine whether a sequence of random signal is the watermark. In our approach, we embed the watermark with visual recognizable patterns into the images by modifying the frequency part of the image. In the proposed method, original image data and grey-level digital watermark are decomposed into wavelet coefficients. The performance of the proposed watermark is robust to a variety of signal distortions, such as JPEG, image cropping, sharpening, median filtering, and incorporating attacks.