Phase watermarking of digital images

摘要: A watermark is an invisible mark placed on image that can be detected when the compared with original. This designed to identify both source of as well its intended recipient. The should tolerant reasonable quality lossy compression using transform coding or vector quantization. Standard processing operations such low pass filtering, cropping, translation and rescaling not remove mark. Spread spectrum communication techniques matrix transformations used together design watermarks are robust tampering visually imperceptible. paper discusses for embedding marks in grey scale digital images. It also proposes a novel phase based method conveying information. In addition, use optimal detectors identification proposed.