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dev:gdal [2011/12/09 00:10]
admin
dev:gdal [2011/12/22 13:32] (current)
admin
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 Using GDAL, Dinamica EGO can write maps in the following file formats. ​ Using GDAL, Dinamica EGO can write maps in the following file formats. ​
  
-^ Description ^ Extension ^+^ Description ​((File formats marked with a star (*) do not define an extension. To workaround this limitation, Dinamica EGO invents the corresponding extension using the file format description)) ​^ Extension ^
 | VRT | .vrt | | VRT | .vrt |
 | GTiff | .tif | | GTiff | .tif |
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 | SAGA | .sdat | | SAGA | .sdat |
  
-File formats marked with a star (*) do not define an extension. To workaround this limitation, Dinamica EGO invents the corresponding extension using the file format description.+Some important notes:
  
-<​note>​ +  ​* The support to AAIGrid (.asc) in GDAL is read only. So, Dinamica EGO provides the writing capability itself. This format can read images using [[:Cell Type Type|cell types]] "​Signed 32 Bit Integer"​ and "IEEE 754 32 Bit Real"​. ​All cell types can be written, but they are automatically ​converted back to one of those formats next time Dinamica reads the image again.
-  ​* The support to AAIGrid (.asc) in GDAL is read only. So, Dinamica EGO provides the writing capability itself. This format can read and write images using [[:Cell Type Type|cell types]] "​Signed 32 Bit Integer"​ and "IEEE 754 32 Bit Real"​. ​The cell type is detected ​automatically.+
  
   * The support to ERMapper (.ers) in GDAL ignores class names. To workaround this limitation, support to reading and writing this file format is provided by Dinamica EGO itself.   * The support to ERMapper (.ers) in GDAL ignores class names. To workaround this limitation, support to reading and writing this file format is provided by Dinamica EGO itself.
-</note>+ 
 +==== GDAL Limitations ==== 
 + 
 +GDAL (and some times the underlying file format) imposes limitations on the representation of projections,​ category names, their corresponding colors and layer names. The limitations and their corresponding workaround are listed in the table below: 
 + 
 +^ Limitation ^ Workaround ^  
 +| Some file formats do not support the storage of projections ​ | Use a VRT file ((include link to file format description)) or an auxiliary PAM XML file ((include link to file format description)) to keep this information. ​ | 
 +| Several file formats do not support the storage of category names. ​ | To workaround this limitations,​ it is possible to use a VRT file or an auxiliary PAM XML file to keep this information. The ERMapper file format has the best support to category names and colors. ​ | 
 +| Several file formats do not support the storage of category colors. ​ | To workaround this limitations,​ it is possible to use a VRT file or an auxiliary PAM XML file to keep this information. The ERMapper file format has the best support to category names and colors. ​ | 
 +| Several file formats do not support the storage of layer names. ​ | To workaround this limitations,​ it is possible to use a VRT file or an auxiliary PAM XML file to keep this information. The ERMapper file format also has support to layer names. ​ | 
 +| The categories must start from 0 and their definition must be contiguous. ​ | Unfortunately,​ the only way to workaround this limitation is defining dummy categories (Dinamica does this when representing non-contiguous categories in a GDAL supported format) or using the ERMapper file format. ​ | 
 + 
 +==== Dinamica Limitation ==== 
 + 
 +Dinamica only retrieves and uses category names and colors from the first layer/band when using GDAL. All the other layers/​bands are supposed to use the same category names and colors.
  
 ===== Workdir/​folder Names ===== ===== Workdir/​folder Names =====
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 ===== Virtual Format ===== ===== Virtual Format =====
  
-GDAL support a virtual file format called [[http://​www.gdal.org/​gdal_vrttut.html|VRT]]. This format can be used to transform an image defining a different registration info, different classe names and a different color table. A example of a VRT file defined from a two unrelated image files can be found below.+GDAL support a virtual file format called [[http://​www.gdal.org/​gdal_vrttut.html|VRT]]. This format can be used to transform an image defining a different registration info, different classe names and a different color table. It can also be use to create mosaics from several different images. A example of a VRT file defined from a two unrelated image files can be found below.
  
 <file xml test.vrt>​ <file xml test.vrt>​
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 </​VRTDataset>​ </​VRTDataset>​
 </​file>  ​ </​file>  ​
 +
 +===== PAM XML Auxiliary File =====
 +
 +!!!FIXME
 +
 +===== File Filters =====
 +
 +The document below provides some information about the file filters available in the open map file and save map file dialogs:
 +
 +[[https://​docs.google.com/​document/​pub?​id=1pXhk1f8eXugA_2sQ3rqQSZV0KXPVhAtutTRD3LCh9g8]]