Analysis of GeoTag Fields in GeoTiff
LIU Xiu guo 1, HUA Wei hua 2 (1.Faculty of Information Engineering, China University of Geosciences, Wuhan430074, China; 2.The Graduate School, China University of Geosciences, Wuhan430074, China)$$$$
GeoTiff is a special form of Tiff spec. GeoTiff 1.0 adds six GeoTags provided to describe all geographic coordinate information and projection information on the base of Tiff. Using the tags, such as pixel scale, tie points, projection types, coordinate systems etc., you can easily get the latitude and longitude from the raster space of GeoTiff image, and vice versa. Firstly, this thesis introduces three kinds of coordinate systems GeoTiff supporting and discusses the relationships of the six GeoTags; next it describes the meanings and the storing method of them. Then, the thesis gives the method and steps of the conversion between coordinates of raster space and model space according to the principle of GeoTiff image data encoding. Finally, considering the application of GeoTiff, the thesis discusses its merits and forecasts its development scope.