Processing of digital photos of Crested Newts (Triturus cristatus)

Requirements for the pictures

AmphIdent tries to automatically find the ventral pattern of the newt. Because of the longish form of the animals this task is not trivial, which is why the user mostly has to improve the marking of the pattern.

In order to make the marking process as easy as possible the photos should fulfill some requirements:

  • The animals should be photographed vertically, with the head up.
  • The animals should lie as straigt as possible. Although AmphIdent is able to consider bent patterns, the marking is easier with straight bodies.
  • Take care of a good contrast between animal and background. Ideal backgrounds are as white as possible.
  • Photograph the animals with bright and even light. Sparkling or shadows on the patterns lead to errors in the detection of the spots.
  • Don't process unsharp photos.

Resolution of the photos

Example image of newt pattern suitable for individual identification via automatic pattern matching. Too small resolutions compromise the sharpness of the patterns, too large resolutions lengthen the computation time for marking the pattern.

An optimal photo contains the animal with a resolution of approximately 300x600 pixels. The resolution of the picture then depends on the size of the individual on the photo.

A sample photo

The adjacent photo is ideal. The resolution is 410x870 pixels, the background is relatively bright, and the animal lies almost straight and all spots are easily recognizable.

Click the photo to display it in original size.