Research On The Height Of Urban Buildings Based On Urban IKONOS Image Shadow

With the rapid development of population and economy, urbanization process accelerated. Therefore, it is meaningful to get the urban change information for city planning and development. The target feature extraction from remote sensing image has received considerable attention in past decades, especially building extraction. Now it is still a hot topic.This thesis has studied the extraction of building height from the building shadow of IKONOS remote sensing images based on the study area of Xiamen.The thesis content is embodied as follows.1n An automatic urban building shadow extraction method is proposed. The method makes good use of shadow cast by buildings in remote sensing images, including image enhancement, mathematical morphology, image segmentation and shadow extraction. Experimental results showed that this method is fast and effective. And the shape and size of the shadow is well.2, A novel method for water removal from building shadow is proposed.In the gray-scale characteristics waters is similar to the building shadow.So building shadow detection are always influenced by the water on supervised classification. Based on characteristics of the different wavelength images, the shadows are detected by supervised classification and algebraic operations.Experimental results showed that the building shadows on the water are detected.And the method increases the detecting accuracy.3> By analysis the relationship between building shadow and sun elevation, sun azimuth, satellite elevation, satellite azimuth, this thesis suggests a calculation formula for the building height based on the shadow.The building height from shadow is extracted by method of measuring tools and average.And the height calculated value compared with measured values of the study area in Xiamen.Finally the accuracy evaluation and error analysis of the experiment result was done.