Figure 6.

Polarization distance in image polarimetry for the tail of a stomatopod Odontodactylus latirostris. (a) Example of standard image polarimetry. E-vector axis (middle) and degree (right) of polarized light were calculated from four original images (one of which is shown on the left) taken through linear polaroid filters at 0°, 45° and 90°. Note that any areas with a degree of polarized light less than 5% are assigned black. (b) Photographs taken through horizontal and vertical linear polaroid filters (left) are first filtered to match a polarization sensitivity S_p of 10 (see text for calculation) and then used to compute polarization distance (right) for all pixels relative to the background area b (left dotted rectangle). In this example, the uropods of the stomatopod are highly linearly polarized, and so have a large polarization distance (grey) relative to the unpolarized background (white).