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Full-Text Articles in Physical Sciences and Mathematics
Mining Urban Perceptions From Social Media Data, Yu Liu, Yihong Yuan, Fan Zhang
Mining Urban Perceptions From Social Media Data, Yu Liu, Yihong Yuan, Fan Zhang
Journal of Spatial Information Science
This vision paper summaries the methods of using social media data (SMD) to measure urban perceptions. We highlight two major types of data sources (i.e., texts and imagery) and two corresponding techniques (i.e., natural language processing and computer vision). Recognizing the data quality issues of SMD, we propose three criteria for improving the reliability of SMD-based studies. In addition, integrating multi-source data is a promising approach to mitigating the data quality problems.
A Combined Gis And Stereo Vision Approach To Identify Building Pixels In Images And Determine Appropriate Color Terms, Philip James Bartie, Femke Reitsma, Steven Mills
A Combined Gis And Stereo Vision Approach To Identify Building Pixels In Images And Determine Appropriate Color Terms, Philip James Bartie, Femke Reitsma, Steven Mills
Journal of Spatial Information Science
Color information is a useful attribute to include in a building's description to assist the listener in identifying the intended target. Often this information is only available as image data and not readily accessible for use in constructing referring expressions for verbal communication. The method presented uses a GIS building polygon layer in conjunction with street-level captured imagery to provide a method to automatically filter foreground objects and select pixels which correspond to building facades. These selected pixels are then used to define the most appropriate color term for the building and corresponding fuzzy color term histogram. The technique uses …
Using Linear Features For Aerial Image Sequence Mosaiking, Caixia Wang
Using Linear Features For Aerial Image Sequence Mosaiking, Caixia Wang
Electronic Theses and Dissertations
With recent advances in sensor technology and digital image processing techniques, automatic image mosaicking has received increased attention in a variety of geospatial applications, ranging from panorama generation and video surveillance to image based rendering. The geometric transformation used to link images in a mosaic is the subject of image orientation, a fundamental photogrammetric task that represents a major research area in digital image analysis. It involves the determination of the parameters that express the location and pose of a camera at the time it captured an image. In aerial applications the typical parameters comprise two translations (along the x …
Detection And Generalization Of Spatio-Temporal Trajectories For Motion Imagery, Panayotis Partsinevelos
Detection And Generalization Of Spatio-Temporal Trajectories For Motion Imagery, Panayotis Partsinevelos
Electronic Theses and Dissertations
In today's world of vast information availability users often confront large unorganized amounts of data with limited tools for managing them. Motion imagery datasets have become increasingly popular means for exposing and disseminating information. Commonly, moving objects are of primary interest in modeling such datasets. Users may require different levels of detail mainly for visualization and further processing purposes according to the application at hand. In this thesis we exploit the geometric attributes of objects for dataset summarization by using a series of image processing and neural network tools. In order to form data summaries we select representative time instances …