Content Authentication and Forge Detection using Perceptual Hash for Image Database

Abstract

Popularity of digital technology is very high. Number of digital images are being created and stored every day. This introduces a problem for managing image databases and security of images. One cannot determine if an image already exists in a database without exhaustively searching through all the entries. Further complication arises from the fact that two images appearing identical to the human eye may have distinct digital representations, making it difficult to compare a pair of images. Also the security of database server is questionable. The proposed framework provides the content authentication and forges detection of image. This can be done by generating perceptual image hash using SIFT algorithm, Perceptual image hash also known as perceptual image signature. It has been proposed as a primitive method to solve problems of image content authentication. The perceptual image hash is generated by using the perceptual features that are in accordance with human’s visual characteristics. It allows tampering of images to permissible extent e.g. improving slight brightness or contrast in image. A perceptual image hash is expected to be able to survive unintentional distortion and reject malicious tampering within an acceptable extend .Therefore it provides a more efficient approach to analyzing changes of image perceptual content and make sure database server is authenticated or not.