Active key frame selection for 3D model reconstruction from crowdsourced geo-tagged videos

Automatic reconstruction of 3D models is attracting increasing attention in the multimedia community. Scene recovery from video sequences requires a selection of representative video frames. Most prior work adopted content-based techniques to automate key frame extraction. However, these methods take no frame geo-information into consideration and are still compute-intensive. Here we propose a new approach for key frame selection based on the geographic properties of videos. Currently, an increasing number of user-generated videos (UGVs) are collected — a trend that is driven by the ubiquitous availability of smartphones. Additionally, it has become easy to continuously acquire and fuse various sensor data (e.g., geo-spatial metadata) with video to create geo-tagged mobile videos. Our novel technique utilizes these underlying geo-metadata to select the most representative frames. Specifically, a key frame subset with minimal spatial coverage gain difference is extracted by incorporating a manifold structure into reproducing a kernel Hilbert space to analyze the spatial relationship among the frames. Our experimental results illustrate that the execution time of the 3D reconstruction is shortened while the model quality is preserved.