摘要：Images are considered to be natural carriers of information, and a large
number of images are created, exchanged and are made available online. Apart from
creating new images, the availability of number of duplicate copies of images is a
critical problem. Hashing based image copy detection techniques are a promising
alternative to address this problem. In this approach, a hash is constructed by using
a set of unique features extracted from the image for identification. This article
provides a comprehensive review of the state-of-the-art image hashing techniques.
The reviewed techniques are categorized by the mechanism used and compared
across a set of functional & performance parameters. The article finally highlights
the current issues faced by such systems and possible future directions to motivate
further research work.
关键词：Image forensics; Digital watermarking; Image copy detection; Hashing;
based image copy detection.
