  The multi-sensory setups consisting of the laser scanners and cameras are
popular as the measurements complement each other and provide necessary
robustness for applications. Under dynamic conditions or when in motion, a
direct transformation (spatial calibration) and time offset between sensors
(temporal calibration) is needed to determine the correspondence between
measurements. We propose an open-source spatiotemporal calibration framework
for a camera and a 3D laser scanner. Our solution is based on commonly
available chessboard markers requiring one-minute calibration before the
operation that offers accurate and repeatable results. The framework is based
on batch optimization of point-to-plane constraints with a time offset
calibration possible by a novel continuous representation of the plane
equations based on a minimal representation in the Lie algebra and the use of
B-splines. The framework's properties are evaluated in simulation while
correctness is verified with two distinct sensory setups with Velodyne VLP-16
and SICK MRS6124 3D laser scanners.
