New imaging mobile mapping device based on high resolution videogrammetry for large-scale outdoor 3D reconstruction

Abstract

In recent years, a new generation of instruments has appeared that are motion-based capture. These systems are based on a combination of techniques, among which LIDAR stands out. In this article we present a new proposal for a 3D model generation instrument based on videogrammetry. The prototype designed consists of two cameras connected to a computer system. One of the cameras is in charge of running VisualSLAM and guiding the user in real time at the moment of data acquisition; the other camera, with a higher resolution, saves the images and, thanks to a refined 3D-Based frame selection algorithm, processes them using automatic photogrammetric procedures, generating one or more point-clouds that are integrated to give way to a high-density and high-precision 3D colour point-cloud.The paper evaluates the proposal with four case studies: two of an urban nature and two related to historical heritage. The resulting models are confronted with the Faro Focus3D X330 laser scanner, classic photogrammetric procedures with reflex camera and Agisoft metashape software and are also confronted with precision points measured with a total station. The case studies show that the proposed system has a high capture speed, and that the accuracy of the models can be competitive in many areas of professional surveying and can be a viable alternative for the creation of instruments based on videogrammetry.