Tae-Hyun Hwang

MPEG-7 metadata for video-based GIS applications

In this paper, we present a MPEG-7 metadata scheme designed for a video-based Geographic Information System (VideoGIS). Recently, VideoGIS have been developed for integrated management of spatial data such as map, 3D graphic, still image, and video to provide better and more realistic information of spatial objects. Main functions of VideoGIS are to calculate 3D geographic position of a spatial object and to search image and video that correspond to the object. In this paper, a MPEG-7 metadata scheme is proposed for emerging Location-Based Services (LBS), e.g., tourist information and restaurant reservation services, which becomes more and more popular in emerging mobile environments.

An advanced approach for navigation and image sensor integration for land vehicle navigation

In the last couple of decades, the demands of navigation technology have been increasing and the technology has been expanded in several application areas including automated car navigation and mobile mapping systems. However, there has been little research and study on the integration of GPS, IMU, and image sensors such as CCDs, and video cameras. This paper aims at aiding inertial navigation sensors with image sensor measurements and distance measurements even in an environment with no GPS assistance. Using an extended Kalman filtering technique, a novel integration scheme, a multi-modal approach, is presented in this paper for various sensors such as IMU, GPS, odometer, and CCD cameras to improve positioning accuracy. Experimental results show that the proposed multimodal approach can be used to enhance positioning accuracy during GPS outages.

Generation of video metadata supporting video-GIS integration

Geospatial information expressed by video can provide more realistic and comprehensible information that cannot be obtained from digital map. We introduce video and integrate it to CIS by supporting video-map cross reference and bidirectional search. To support content-based search of geospatial objects appearing on video, we generate video metadata that has necessary information of geospatial objects. The most important part of the video metadata is outline of object on video frame. The outline of an object varies frame to frame, and thus should be generated for every frame in which the object appears. Because the object moves rapidly between video frames collected with 1-second interval, object tracking cannot be easily done by simple algorithm. In this paper, we devise a semi-automatic object tracking method by combining photogrammetric solution with image-based method.

Updating geospatial database: an automatic approach combining photogrammetry and computer vision techniques

In this paper, we suggest an automatic approach based on photogrammetry and computer vision techniques to build and update geospatial database more effectively. Stereo image or video is spotlighted as a useful media for constructing and representing geospatial database. We can acquire coordinates of geospatial objects appearing in image frames captured by camera with mobile mapping system, but quite a lot of manual input are required. We suggest a change detection method for geospatial objects in video frames by combining computer vision technique and photogrammetry. With the suggested scheme, we can make the construction and update process more efficient and reduce the update cost of geospatial database.

A framework of augmented reality for geotagged videos

In this paper, we present a prototype system and a framework for the implementation of augmented reality system for a geotagged video. In the proposed system, a live video is captured by a mobile phone and the corresponding geo-coordinates and orientation parameters are recorded at the same time. Based on the parameters, the information about buildings around the center position of the mobile phone is obtained from a database called V-World (http://map.vworld.kr) that is an open platform built by Korean government and freely available through the online. More specifically, the keyhole markup language (KML) is used for the description of the parameters for a captured video, and a detailed description about a chosen building, e.g., the name and the height of the building are obtained from V-World and overlaid on the video. The proposed approach is based on a database freely available through the online and a new database is not required to be constructed for the service, which is very essential to provide augmented reality services.

An indexing method for spatial object in video using image processing and photogrammetry

To support video-map cross-reference and bi-directional search, it is necessary to index spatial object with regard to each video frame. However, it costs a great deal of effort to index spatial objects in all frames of video whose frame rate is about 30 frames/second. Therefore, we index spatial object only about 1 random frame per second, and index the spatial object in other frames by interpolation. However, when processing video frames with 1-second interval, the low spatial redundancy of spatial objects in the video makes the indexing of spatial objects difficult because object tracking is nearly impossible only with image-based method. In this paper, we devise an efficient indexing method for spatial objects in video frame, by combining photogrammetric solution with image-based method. The suggested method can efficiently index spatial object in video frames and support content-based retrieval of spatial object in video