Photographic paper classification via local radius index metric

The ability to recognize different types of photographic paper can be useful when attributing photographs to specific photographers or eras. This paper uses the recently developed texture feature, Local Radius Index (LRI), and the similarity metrics based on it, to classify photographic papers, from raking light photos of such. The results show that LRI leads to better classification of photographic papers than previous methods. They also suggest the ability to distinguish photographic papers by brand/style and reflectance.