[Qgis-user] map collars

[Chris h]

On Wednesday 18 March 2009 16:07:18 MS wrote:
> I realize this goes into other software on a qgis list, but I wonder
> with GDAL or GRASS one can accomplish this.
>
> It is really a raster clip that would work well, especially if the
> next step is mosaic'ing the rasters.  Are these quad ma

The charts are NOAA BSB rasters.

Posted the same questions to the grass list and the response was positive:
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>> WIth r.in.poly you could "digitize" the area of interest, then use
>> r.mask to remove the outside area, then r.patch everything.
>> With a small script you could generate the ASCII polygon file
>> for r.in.poly based on the map extent.
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Standalone gdal will not do it, especially if you want to automate the process 
and have concerns with the osmerander bug which in a marine charting 
environment could be rather interesting. The charts will in fact be tiled and 
made available via mapserver wms. 

The only issue for me is that I must learn each step with each application. 
Hence I went the easy route first to see what can be done with qgis. 

There is a very good new program out for creating tiles, maptiler.org and need 
to see and learn if the datum and projection can be changed. Its basically a 
front end to galtiler. 

Thanks for all the suggestions. 


-- 
/ch