An automated program to find animals and crop photographs for individual recognition

Detailed data on individual animals are critical to ecological and evolutionary studies, but attaching identifying marks can alter individual fates and behavior leading to biases in parameter estimates and ethical issues. Individual-recognition software has been developed to assist in identifying many species from non-invasive photographic data. These programs utilize algorithms to find unique individual characteristics and compare images to a catalogue of known individuals. Currently, all applications for individual identification require manual processing to crop images so only the area of interest remains, or the area of interest must be manually delineated in each image. Thus, one of the main bottlenecks in processing data from photographic capture-recapture surveys is in cropping to an area of interest so that matching algorithms can identify the individual. Here, we describe the development and testing of an automated cropping program. The methods and techniques we describe are broadly applicable to any system where raw photos must be cropped down to a specific area of interest before pattern recognition software can be used for individual identification. We developed and tested the program for use with identification photos of wild giraffes.



Work Title An automated program to find animals and crop photographs for individual recognition
Open Access
  1. Patrick Buehler
  2. Bill Carroll
  3. Ashish Bhatia
  4. Vivek Gupta
  5. Derek E. Lee
  1. Animal detection
  2. Capture-recapture
  3. Computer vision
  4. Histogram of oriented gradients
  5. Image processing
  6. Individual identification
  7. Photo identification
License In Copyright (Rights Reserved)
Work Type Article
  1. Ecological Informatics
Publication Date February 4, 2019
Publisher Identifier (DOI)
Deposited July 12, 2023




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Work History

Version 1

  • Created
  • Added Buehler_et_al_2019_cropping.pdf
  • Added Creator Patrick Buehler
  • Added Creator Bill Carroll
  • Added Creator Ashish Bhatia
  • Added Creator Vivek Gupta
  • Added Creator Derek E. Lee
  • Published
  • Updated Keyword, Publication Date Show Changes
    • Animal detection, Capture-recapture, Computer vision, Histogram of oriented gradients, Image processing, Individual identification, Photo identification
    Publication Date
    • 2019-03-01
    • 2019-02-04
  • Updated