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| GeoCommunity Mailing List |
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| Mailing List Archives |
| Subject: | Re: GISList: de facto standards |
| Date: |
08/02/2003 09:10:01 PM |
| From: |
Frank Warmerdam |
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viktoras wrote:
>
> Hi ,
>
> I would like to ask what universal data formats (both "old" and
> "new", binary or ASCII) should be used to ensure portability of digital
> maps - both raster and vector among most of the available GIS software
> without a risk of information loss.
>
> Thanks in advance
> Viktoras
Viktoras,
You haven't provided much in the way of constraints on this request.
If you are looking for current formats for raster and vector data that are
widely supported in GIS applications I would suggest Shapefiles for vector
and GeoTIFF for raster. Both are very widely supported (though to varying
degrees), and reasonably compact binary formats.
There are some data model limitations of these formats, especially for shapefiles.
For instance, each shapefile set must have only one geometry type (arc, polygon,
point) and shapefiles use dbf files for attributes which can only have short
field names (11 characters long at most?). Coordinate system support in
applications reading shapefiles will vary, with most ignoring shapefile
.prj files which may take two forms, Arc/Info 7.x format and ArcGIS format
(an ESRI specific form of OpenGIS Well Known Text). Also, shapefiles carry no
presentation information, so it is good for transporting raw GIS layers, but not
final map presentations or CAD drawings with complex drawing characteristics.
Shapefiles make a good lowest common denominator format, but if you have a
sophisticated data model it may be hard to provide it in shapefile format.
GeoTIFF has pretty good coordinate system support, but for some many
applications will ignore the coordinate system and only pick up the
georeferencing coordinates. In general TIFF and GeoTIFF are quite flexible,
but the more esoteric the options you use the less applications that will
support the files properly.
My opinion of course, your milage may vary ... better advice can be provided
if you give more specific requirements.
Best regards,
--
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up | Frank Warmerdam, warmerdam@pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush | Geospatial Programmer for Rent
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