PhotoId-Whale: Blue whale dorsal fin classification for mobile devices

• Published in: PLOS ONE
• Main Authors: Ramos-Arredondo, Rosa I., Carvajal-Gámez, Blanca E., Gendron, Diane, Gallegos-Funes, Francisco J., Mújica-Vargas, Dante, Rosas-Fernández, J. B.
• Format: Text
• Language: English
• Published: Public Library of Science 2020
• Subjects: Research Article; Baja; Tegra; Blue whale
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7549799/; http://www.ncbi.nlm.nih.gov/pubmed/33044975; https://doi.org/10.1371/journal.pone.0237570

Photo-identification (photo-id) is a method used in field studies by biologists to monitor animals according to their density, movement patterns and behavior, with the aim of predicting and preventing ecological risks. However, these methods can introduce subjectivity when manually classifying an individual animal, creating uncertainty or inaccuracy in the data as a result of the human criteria involved. One of the main objectives in photo-id is to implement an automated mechanism that is free of biases, portable, and easy to use. The main aim of this work is to develop an autonomous and portable photo-id system through the optimization of image classification algorithms that have high statistical dependence, with the goal of classifying dorsal fin images of the blue whale through offline information processing on a mobile platform. The new proposed methodology is based on the Scale Invariant Feature Transform (SIFT) that, in conjunction with statistical discriminators such as the variance and the standard deviation, fits the extracted data and selects the closest pixels that comprise the edges of the dorsal fin of the blue whale. In this way, we ensure the elimination of the most common external factors that could affect the quality of the image, thus avoiding the elimination of relevant sections of the dorsal fin. The photo-id method presented in this work has been developed using blue whale images collected off the coast of Baja California Sur. The results shown have qualitatively and quantitatively validated the method in terms of its sensitivity, specificity and accuracy on the Jetson Tegra TK1 mobile platform. The solution optimizes classic SIFT, balancing the results obtained with the computational cost, provides a more economical form of processing and obtains a portable system that could be beneficial for field studies through mobile platforms, making it available to scientists, government and the general public.