Transformation and application of Google Earth images

摘要

Except using the powerful functions provided by Google Earth to browse geographic information of the world the users want to realize other practical applications through downloading the images provided by GE, for example, recognization, feature extraction and digitising some geographic information on the new images to update the old database, imagebased mapping, overlay other geographic data and realize the functions of display, query and analyse, etc. So we need clip, stitching and projection transformation to the images of GE and get accurate registration with other types of geographic information. This paper analysed the layered organizing method of GE images. That is to realize multi-view browsing and high speed transmission in internet GE uses the super-high efficiency compression technique to images and builds database in layered pyramid structure to mass muti-resolution images. The paper discusses Mercator projection principle. As an example, through processing the GE images and getting pixel value the transformation of Mercator projection and Gauss projection and the resample method of image pixel are studyed. Calculational methods for the image transformation are provided, that may provide ideas and techniques to similar GE image application.