GeoTIFF (Georeferenced TIFF)
Open BetaGeoTIFF er et rasterformat med indlejret georeferering. Kortet gemmes som et TIFF-billede med koordinater, projektion og metadata. De facto-standarden for georefererede rasterkort.
Vigtigste funktioner
Om formatet GeoTIFF
GeoTIFF is an ordinary TIFF with coordinates written into its tags: where the top left corner lies, what the pixel size is and which coordinate system all of it is recorded in. A GIS program opens such a file and immediately puts the picture in its place on the ground — there is nothing to georeference by hand.
A raster map is needed where vectors are excessive or awkward: an underlay beneath your own layers, a print-ready original, an overlay on a satellite image, material for interpretation and for raster algorithms.
The file contains a map page drawn in the chosen style and saved as a georeferenced image. The default resolution is 300 DPI, that is print quality; the default sheet is A4 landscape. LZW compression is lossless, yet noticeably smaller than an uncompressed TIFF.
The default coordinate system is WGS84 (EPSG:4326); the georeferencing sits in the file's own tags, so there is no need to keep any companion files alongside it.
Hvilket program åbner GeoTIFF-filer
Følgende programmer og applikationer kan åbne, redigere og arbejde med GeoTIFF (Georeferenced TIFF)-filer (.tif), der er eksporteret fra OSM2CDR:
Format specifications
- Open standard
- 2D only
- Lossless (no quality loss)
- No attributes
- Output: 1 file
- GeoTIFF (OGC) with georeferencing tags. Single .tif file; default LZW compression. Standard for GIS raster.
Hvem bruger GeoTIFF-kort
Sådan eksporterer du GeoTIFF
Sådan åbner du filen efter eksporten
- QGIS (free) — drag the .tif into the program window: the layer lands in place and the projection is detected automatically.
- ArcGIS and Global Mapper — Add Data; the raster attaches as an underlay beneath your vector layers.
- Google Earth Pro — File → Import, choose the GeoTIFF: the map lands on the globe (for heavy files the program will offer to reduce the resolution).
- GDAL — gdalinfo map.tif shows the georeferencing and the projection, and gdalwarp -t_srs EPSG:3857 map.tif out.tif reprojects the raster for a web map.
- Printing — the file is calculated for 300 DPI and goes to print as is; in Photoshop or GIMP do not change the pixel dimensions, otherwise you will lose both quality and the match to the scale.
Populære kort i GeoTIFF
Få korteksport i GeoTIFF (Georeferenced TIFF)
Download professionelle GeoTIFF-kort fra OpenStreetMap. Øjeblikkelig generering, ethvert område.
Ofte stillede spørgsmål
Sammenlign med andre formater
Relaterede formater
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