Video-Based Point Cloud Generation Using Multiple Action Cameras

Abstract

ABSTRACT:Due to the development of action cameras, the use of video technology for collecting geo-spatial data becomes an important trend. The objective of this study is to compare the image-mode and video-mode of multiple action cameras for 3D point clouds generation. Frame images are acquired from discrete camera stations while videos are taken from continuous trajectories. The proposed method includes five major parts: (1) camera calibration, (2) video conversion and alignment, (3) orientation modelling, (4) dense matching, and (5) evaluation. As the action cameras usually have large FOV in wide viewing mode, camera calibration plays an important role to calibrate the effect of lens distortion before image matching. Once the camera has been calibrated, the author use these action cameras to take video in an indoor environment. The videos are further converted into multiple frame images based on the frame rates. In order to overcome the time synchronous issues in between videos from different viewpoints, an additional timer APP is used to determine the time shift factor between cameras in time alignment. A structure form motion (SfM) technique is utilized to obtain the image orientations. Then, semi-global matching (SGM) algorithm is adopted to obtain dense 3D point clouds. The preliminary results indicated that the 3D points from 4K video are similar to 12MP images, but the data acquisition performance of 4K video is more efficient than 12MP digital images.

Evaluation of the Quality of Action Cameras With Wide-Angle Lenses in Uav Photogrammetry

“…An increase in accuracy of factor 2 could be achieved using the undistorted images. Similar investigations using the GoPro Hero4 are presented by Teo (2015) using Photomodeler and Agisoft PhotoScan. The application of an action camera on a low-cost aerial vehicle is analysed by Ballarin et al (2015).…”

Calibration Low-Cost Cameras with Wide-Angle Lenses for Measurements

“…In case of calibration procedures it is possible to adopt the assumptions similar to the calibration action cameras like GoPro Hero 4 which are equipped in wide-angle (fisheye) lenses. To this time several research work related to the calibration and application of these cameras in the photogrammetric perfected has been carried out [8], [25], [26]. In above articles results relating to calibration of the GoPro Hero 3 and GoPro Hero 4 cameras and of their uses to photogrammetric goals were discussed.…”

Geometrical Network Model Generation Using Point Cloud Data for Indoor Navigation

“…These indoor positioning techniques are required to satisfy positioning accuracy, availability, continuity, and cost. In three-dimensional (3D) model generation in indoor mapping, there are various approaches, such as 3D modeling using building drawings, 3D model generation from point clouds using a terrestrial laser scanner and mobile laser scanning systems with a simultaneous localization and mapping algorithm (Nakagawa et al 2014), 3D model generation from point clouds using a time-of-flight area scanner (Henry et al 2012), and 3D texture model generation based on structure from motion, multi-view stereo, and photogrammetry (Teo, 2015). In all these approaches, there are technical issues to be discussed, such as the 3D measurement accuracy, model generation accuracy, processing speed and processing cost.…”