A multi-view annotation tool for people detection evaluation

In this paper we introduce a novel multi-view annotation tool for generating 3D ground truth data of the real location of people in the scene. The proposed tool allows the user to accurately select the ground occupancy of people by aligning an oriented rectangle on the ground plane. In addition, the height of the people can also be adjusted. In order to achieve precise ground truth data the user is aided by the video frames of multiple synchronized and calibrated cameras. Finally, the 3D annotation data can be easily converted to 2D image positions using the available calibration matrices. One key advantage of the proposed technique is that different methods can be compared against each other, whether they estimate the real world ground position of people or the 2D position on the camera images. Therefore, we defined two different error metrics, which quantitatively evaluate the estimated positions. We used the proposed tool to annotate two publicly available datasets, and evaluated the metrics on two state of the art algorithms.