Publication

Abstract : pAuthenticity and integrity of digital media is of primary concern in transmission and reception of multimedia data. Wenbsp;propose a digital image watermarking scheme that dependsnbsp;solely on the secrecy of the security key and not that of thenbsp;watermarking algorithm. The proposed digital watermarkingnbsp;scheme is based upon Discrete Cosine Transform and usesnbsp;properties of the transform to achieve the least visiblenbsp;distortion in the watermarked image. The proposed techniquenbsp;involves a unique method for spreading, embedding andnbsp;extracting the watermark. It allows for five separate levels ofnbsp;security, all of which must be affirmed to. The watermarkednbsp;images were subjected to image cropping, JPEG lossynbsp;compression and other destructive attacks with a minimumnbsp;level of 65% extraction. The proposed technique also supportsnbsp;implementation using Discrete Wavelet Transforms (DWT).nbsp;Keywords: Digital Watermarking, quantization, iscretenbsp;Cosine Transform, Discrete Wavelet Transform/p