An affine invariant curve matching method for photo-identification of marine mammals

Individual identification of marine mammals is of interest to marine biologists. This paper aims at the recognition of the edges associated with marine mammals whose pictures are taken under affine transformations. The introduced affine curve matching method uses the area of mismatch between a query and a database curve. This area is obtained by optimally aligning the curves based on the minimum affine distance involving their distinguishing points. The method is applied to databases of sea lions, gray whales, and dolphins, and its performance is compared with two other affine curve matching methods. The results show that the introduced curve matching approach outperforms the other approaches and thus further reduces the search time for identifying an individual. The developed method is of general purpose as it can be used for other affine curve matching applications.