GeoTIFF

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A GeoTIFF is a special form of a TIFF image, i.e. a file format for storing image data ( file name extension .geotiff , often just .tif ). Since the TIF format allows loss-free storage, it is well suited for processing geographic data, since satellite and aerial images or other raster data often require a high level of imaging accuracy.

The specialty of GeoTIFF compared to the normal TIF format is that special data about the georeference is embedded in the image file in addition to the visible raster data. This includes coordinates for georeferencing the image section and for the map projection used : The file contains specific information about the coordinate reference system .

In contrast to GeoJPEG or normal TIF format, the information is not stored in a separate file ( world file ), but directly in the meta tags of the image, whereby six tags are used for the geographic information. If necessary, these tags can be expanded to include additional fields.

GeoTIFF files can be compressed with all algorithms that are possible for the TIF format, in addition to various lossless methods, also with lossy JPEG compression, with which a significant reduction in file size can be achieved at the expense of image quality. However, not every application supports all compression algorithms permitted by the TIF format.

The initiative to create the GeoTIFF format goes back to the Intergraph company . This topic has been dealt with since the early 1990s and a large number of companies and representatives of government organizations have been won over as supporters. They include well-known companies and institutions in the GIS sector such as ESRI , ERDAS and the USGS . GeoTIFF has developed as a quasi-standard for displaying raster data and is supported by most GIS programs that process raster data as well as some image editing programs. The image information can be displayed in any program that supports the normal TIFF standard.

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