Calibration and correction of vignetting effects with an application to 3D mapping
Calibration and correction of vignetting effects with an application to 3D mapping
复制标题
通过 3D 映射应用来校准和校正渐晕效果
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
M. Vincze
中科院分区：
文献类型：
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作者：
Sergey V. Alexandrov;J. Prankl;M. Zillich;M. Vincze
廉价的RGB-D传感器在机器人中无处不在。它们通常包含一个消费级彩色相机，该相机具有显著的光学非线性，通常称为渐晕效应。例如，在华硕Xtion Live Pro相机中，角落中的像素比图像中心的像素暗两倍。这会使使用这种相机构建的3D地图的视觉外观变差。我们提出了一个简单的校准方法，只需要一张白色纸作为校准对象，并允许可靠地恢复的相机的渐晕响应。我们展示了多个流行的RGB-D传感器的校准结果，并表明使用非参数响应模型去除渐晕效应会导致重建地图的颜色一致性得到改善。此外，我们展示了如何有效地补偿由相机的自动白色平衡和曝光时间控制引起的颜色变化。
Cheap RGB-D sensors are ubiquitous in robotics. They typically contain a consumer-grade color camera that suffers from significant optical nonlinearities, often referred to as vignetting effects. For example, in Asus Xtion Live Pro cameras the pixels in the corners are two times darker than those in the center of the image. This deteriorates the visual appearance of 3D maps built with such cameras. We propose a simple calibration method that only requires a sheet of white paper as a calibration object and allows to reliably recover the vignetting response of a camera. We demonstrate calibration results for multiple popular RGB-D sensors and show that removal of vignetting effects using a nonparametric response model results in improved color coherence of the reconstructed maps. Furthermore, we show how to effectively compensate color variations caused by automatic white balance and exposure time control of the camera.