Facade Texture Generation and Mapping Using Digital Videos

Abstract

Three-dimensional (3D) building model is one of the most important components in a cyber city implementation and application. A realistic texture mapping of building models not only supplies authentic appearance of the models in visualization, it can also provide useful and sometimes critical features in complex applications. However, currently, most building models do not have sufficient and accurate texture information. In order to provide accurate texture attributes to 3D building models, this study developed a highly automated facade texture generation and mapping system for 3D building modeling. Seamless and photo-realistic texture mosaics of building facades were generated from video sequences acquired with consumer digital cameras and digital video (DV) camcorders. Extracted frame images were registered using a developed algorithm based on interest points identified semi-automatically to address concerns on the geometric alignment. A polygon-based blending algorithm based on alpha blending was then applied to integrate colors and shadings over the overlapped regions of adjacent images. As a result, the produced facade textures were continuous in both geometric outlines and color domains. Occlusions of generated facade texture mosaics were automatically identified and mended through a series of morphological operations. The corrected facade textures were mapped onto corresponding building facets correctly and efficiently using linear or parametric transformations. Test experiments conducted in this study demonstrated that the resultant building models had more complete and accurate texture attributes as well as near photo-realistic appearances. More importantly, comparing to conventional photo-based building texture mapping techniques, the developed algorithms are highly automated and provide a great advantage in large-scale cyber city implementations and visualizations.