Network camera apparatus, network camera server and digital video recorder for preventing forgery and alteration of a digital image, and apparatus for authenticating the digital image from said apparatus, and method thereof

摘要

The present invention discloses a network camera apparatus, network camera server and digital video recorder which makes it possible to prevent a digital image from being forged or altered by embedding a watermark into an image signal input through a camera in a real time. Two types of watermark, i.e. a robust watermark for authenticating whether the image is original image or not and a fragile watermark whether the image is forged or altered or where the forgery or alteration of image takes place. An authentication apparatus for authenticating the watermark-embedded image is further disclosed.