Image Authentication Method Based on DWT In Color JPEG Images

This paper presents a novel watermarking method that embeds authentication information into color JPEG format images based on discrete wavelet transforms. This is done by first acquiring the gray values matrix from the color image, then identifying low and high frequency coefficients by using a two-dimensional discrete wavelet transform. The authentication information is embedded into the low coefficients by modifying the low coefficientspsila mean values. Experimental results have shown this algorithm to produce a robust and imperceptible watermark. Furthermore, this algorithm allows detection and identification of any alterations or damage done to the copyrighted image. Thus, this research proposes a method of watermarking that effectively counters the illegal tampering and piracy of copyrighted color JPEG images.