Integral Curvature Representation and Matching Algorithms for Identification of Dolphins and Whales

Hendrik J. Weideman, Zachary M. Jablons, Jason Holmberg, Kiirsten Flynn, John Calambokidis, Reny B. Tyson, Jason B. Allen, Randall S. Wells, Krista Hupman, Kim Urian, Charles V. Stewart; Proceedings of the IEEE International Conference on Computer Vision (ICCV), 2017, pp. 2831-2839

Abstract


We address the problem of identifying individual cetaceans from images showing the trailing edge of their fins. Given the trailing edge from an unknown individual, we produce a ranking of known individuals from a database. The nicks and notches along the trailing edge define an indi- vidual's unique signature. We define a representation based on integral curvature that is robust to changes in viewpoint and pose, and captures the pattern of nicks and notches in a local neighborhood at multiple scales. We explore two ranking methods that use this representation. The first uses a dynamic programming time-warping algorithm to align two representations, and interprets the alignment cost as a measure of similarity. This algorithm also exploits learned spatial weights to downweight matches from regions of un- stable curvature. The second interprets the representation as a feature descriptor. Feature keypoints are defined at the local extrema of the representation. Descriptors for the set of known individuals are stored in a tree structure, which al- lows us to perform queries given the descriptors from an un- known trailing edge. We evaluate the top-k accuracy on two real-world datasets to demonstrate the effectiveness of the curvature representation, achieving top-1 accuracy scores of approximately 95% and 80% for bottlenose dolphins and humpback whales, respectively.

Related Material


[pdf] [arXiv]
[bibtex]
@InProceedings{Weideman_2017_ICCV,
author = {Weideman, Hendrik J. and Jablons, Zachary M. and Holmberg, Jason and Flynn, Kiirsten and Calambokidis, John and Tyson, Reny B. and Allen, Jason B. and Wells, Randall S. and Hupman, Krista and Urian, Kim and Stewart, Charles V.},
title = {Integral Curvature Representation and Matching Algorithms for Identification of Dolphins and Whales},
booktitle = {Proceedings of the IEEE International Conference on Computer Vision (ICCV) Workshops},
month = {Oct},
year = {2017}
}