Placing anurans in water can improve photo-based individual identification
Fig 2
Agile frog individuals with various skin tones photographed after paper-towel drying (top) and under water (bottom).
For each individual, the two images were captured a few seconds apart, using the same light source, while avoiding direct-light exposure to minimise reflections. Note how submerging in water decreases skin glossiness and shadows caused by uneven body surface, overall improving the perception of contrast between skin tone and pigment patterns. For illustration purposes on this figure, we applied the same exposure curve across all images in RawTherapee (referred to as ‘baseline’ on S2 Fig), and cropped them subsequently.