Vila Oriol, Boada Imma, Raba David, Farres Esteve
Graphics and Imaging Laboratory, University of Girona, 17003 Girona, Spain.
Insylo Technologies S.L., 17003 Girona, Spain.
Sensors (Basel). 2021 Mar 16;21(6):2073. doi: 10.3390/s21062073.
Although low cost red-green-blue-depth (RGB-D) cameras are factory calibrated, to meet the accuracy requirements needed in many industrial applications proper calibration strategies have to be applied. Generally, these strategies do not consider the effect of temperature on the camera measurements. The aim of this paper is to evaluate this effect considering an Orbbec Astra camera. To analyze this camera performance, an experimental study in a thermal chamber has been carried out. From this experiment, it has been seen that produced errors can be modeled as an hyperbolic paraboloid function. To compensate for this error, a two-step method that first computes the error and then corrects it has been proposed. To compute the error two possible strategies are proposed, one based on the infrared distortion map and the other on the depth map. The proposed method has been tested in an experimental scenario with different Orbbec Astra cameras and also in a real environment. In both cases, its good performance has been demonstrated. In addition, the method has been compared with the Kinect v1 achieving similar results. Therefore, the proposed method corrects the error due to temperature, is simple, requires a low computational cost and might be applicable to other similar cameras.
尽管低成本的红-绿-蓝-深度（RGB-D）相机在出厂时已进行校准，但为了满足许多工业应用所需的精度要求，必须应用适当的校准策略。一般来说，这些策略没有考虑温度对相机测量的影响。本文的目的是考虑一款奥普特 Astra 相机来评估这种影响。为了分析该相机的性能，在一个热室中进行了一项实验研究。从这个实验中可以看出，产生的误差可以建模为双曲抛物面函数。为了补偿这种误差，提出了一种两步法，首先计算误差，然后进行校正。为了计算误差，提出了两种可能的策略，一种基于红外畸变图，另一种基于深度图。所提出的方法已在使用不同奥普特 Astra 相机的实验场景以及真实环境中进行了测试。在这两种情况下，都证明了其良好的性能。此外，该方法已与 Kinect v1 进行比较，取得了相似的结果。因此，所提出的方法能够校正温度引起的误差，方法简单，计算成本低，并且可能适用于其他类似的相机。
