, Volume 26, Issue 4, pp 443-446

A simple method using a single video camera to determine the three-dimensional position of a fish

Abstract

In the present paper, we describe a method for recording the coordinates of a fish in an aquarium in a three-dimensional space, using a single video camera and a mirror. We use photogrammetic equations for this, considering the image obtained in the mirror as a virtual image obtained by a second camera. A transformation of the coordinate system is required to express the obtained coordinates in anx,y,z system defined by the edges of the aquarium. The accuracy of the proposed method was estimated, and errors in extreme conditions were found to be 0.8% to 1.2 %, compared with the dimensions of the aquarium used in the test.

We thank Vitor Almada, Pedro Ré, and Lucas Noldus for commenting on the manuscript, and Hunter Halder, who reviewed the English. We would also like to thank two anonymous referees for their constructive criticism. During the preparation of this paper, the authors were supported by a grant from Junta Nacional de Investigação Científica e Tecnológica (JNICT).