Fig. 3
From: Three Dimensional Tracking of Exploratory Behavior of Barnacle Cyprids Using Stereoscopy
Left and right camera images of the applied calibration object. Several matched points which can be used to calculate the camera models are shown in green. In our experiment, because of the limited depth of the container, only underwater points are considered (cyan line indicating the water line), in order to compensate the difference in the refractive indexes (air, water, etc.) [35]