Downloadable software for automated photo-id of harbour seals
The picture on this page illustrates the process of scanning the pelage pattern from a photo showing the left side of a harbour seal. By fitting a 3D surface model to the image the program captures a pattern that is unaffected by the camera angle or posture. It then goes on to compare the new pattern with previous patterns stored in a library and display the most likely matches. The resulting database of match results can be used to provide the usual benefits of mark/recapture studies: monitoring of population size and other parameters, determining the fate of individual animals, encouraging cooperation between different research groups and so on. The same program can also use patterns scanned from the side of the head, shoulder or ventral surfaces.
To try out the software first unzip the following "pv_folders.zip" file to your c: drive, where it will make a "c:\pv\" folder with a number of subfolders containing sample images and pattern extracts (remember to click the "use folder names" option). The "c:\pv\" folder will also contain an Access database called "pv.mdb" and two documents explaining the process of entering new images, extracting patterns from those images and comparing the patterns to the library in order to search for earlier images of the same animal.
Then open the "pv_install.zip" file and double-click the "setup.exe" program. Please answer "yes" to retain any files that would otherwise be overwritten by older files.
Finally open the "extra_install.zip" file and double-click its "setup.exe" program. When installation is complete click on "pv" in the programs list and the shortcut to the "pv.mdb" database. On the database screen click the "run pattern extraction/comparison program" button. Click the "retrieve" button to see the program fit the 3D model to the image displayed on the screen. Click "initial fit" to start the process and then click "fit" (you may need to click it a number of times to get a sensible orientation of the model). See the tutorial documents in the "c:\pv\" folder for further information on running the system.
(note: in case of problems when running the pattern extraction/comparison program from the database screen please use a shortcut to the pv.exe file instead)