Automatic Marker-free Registration of Terrestrial Laser Scans Using Reflectance Features

In our paper we explore the application of the SIFT method on terrestrial laser scan data. The energy of the backscattered laser light is represented in a reflectance image. This representation of the data can be directly used with standard SIFT implementations. We show that the extracted features are good candidates for registration. Furthermore, we show that feature matching based on the feature descriptor gives a sufficient initial configuration for registration of terrestrial laser scans. From the resulting set of matches, we compute the rigid body transform for a pair-wise registration. We show that the approach can be extended to not only automatically register terrestrial laser scans, but also automatically register intensity images taken with a separate camera to the laser data.