Binocular camera trap for wildlife detection

By Zhongke Xu, Liang Sun, Xinwei Wang, Han Dong, Pingshun Lei, Yan Zhou. 2019

Camera traps are commonly used in wildlife monitoring. Traditionally camera traps only capture 2D images of wildlife moving in front of them. However, size information of wildlife is lost, which is vital to determine their ages and genders. To solve this problem, this paper develops a binocular camera trap based on stereo imaging for wildlife detection. The camera trap consists of two cameras, motion sensors, a photosensitive sensor and infrared illumination with the central wavelength of 940nm. Motion sensors output triggers to cameras when animals move past, and then pictures are captured from two different perspectives simultaneously. Meanwhile the photosensitive sensor perceives ambient illumination to control infrared illumination. In this way, the camera trap provides both 2D images of wildlife and their size information obtained by binocular vision. In addition, different from normal binocular cameras placed horizontally, these two cameras are set vertically for the convenience of installation and the expansion of dynamic measure range. As verification, we develop a prototype binocular camera trap to measure a human’s height that is 178cm, and the estimation error approaches 2cm at the distance of 5m.