Semi-automated photograph matching tool developed in collaborative workshop

Quite a bit of the work undertaken at the Plant Conservation Unit has to do with repeat historical photography and the number of sites where repeat photographs have been made by staff and students of the PCU now stands at over 1500.  Once the repeat photograph has been taken, however, it is a fairly laborious process to match the repeat with the original image.  Until now, that is. 

Colleagues and students from the School of Computational and Applied Mathematics at the University of the Witwatersrand and from the Department of Statistical Sciences at UCT  recently met up to develop a semi-automated tool for matching two photographs.  Their activities formed part of a five day annual workshop held under the auspices of WIT’s Mathematics in Industry Study Group (MISGSA) held at the African Institute for Mathematical Sciences (AIMS) in Muizenberg this year.  Sam Jack from the Plant Conservation Unit outlined the broader interest and ecological context for using repeat photography in global change research while students Xichavo Vukeya, Matimba Shingange and Atlegang Molubi applied their mathematical skill and dexterity of trying to develop a quick and easy-to-use tool for matching two images.  Byron Jacobs, Dario Fanucchi and Ian Durbach moderated their work which was presented on Friday 16 January 2015 at AIMS. 

The results are very encouraging and the working model shown during the student’s presentation will go a long way to cutting down on the time taken to match sometimes large number of repeat photographs.  The next steps are to iron out a few of the minor problems and then to integrate this approach with the rePhotoSA website so that all those citizen scientists involved in repeating the historical photographs will have an automated tool to help them match the photographs.  We look forward to when this tool can be fully integrated into the PCU’s database of repeat photographs.

AIMS students and tutors: (from left to right) Xichavo Vukeya, Matimba Shingange, Atlegang Molubi, Sam Jack (PCU), Byron Jacobs, Dario Fanucchi, Ian Durbach (Photo M.T. Hoffman)

Article by M.T. Hoffman