Spiral unique sequence: A new rotation invariant feature for small-size image block matching

Matching features of all image overlapping blocks is a common method to explore duplicated regions. In this way, the block size should be small in order to detect small forgery regions. The problem is how to extract a robust feature for small block size against rotation and compression. In this paper, a new spatial domain feature for block size 8×8 pixels namely Spiral Unique Sequence (SUS) is proposed. The experimental results and SUS feature matching demonstrate that this feature is robust against rotation and compression.