On Fri, Nov 9, 2012 at 2:48 PM, Even Rouault <even.roua...@mines-paris.org> wrote:
> ok, I see what happens. In _3 and _4 cases, the BSB driver manages to compute > a geotransform from the GCPs and then assigns a projection, in addition to the > GCP projection. > In the _1 and _2 cases, the BSB driver doesn't manage to compute the > geotranform from the GCPs (which is a known issue sometimes with this driver, > presumably because it has a too strict tolerance in the computation of the > geotransform from the GCPs), so the projection is only reported by the > GetGCPProjection() method, which the gdalsrsinfo never queries. > > In all cases, gdalinfo does show the projection and/or GCP projection. > > Perhaps gdalsrsinfo should also query the GCP projection if no regular > projection is reported. I've wondered for ages about this driver -- the *.kap files have redundant info -- the projection definition and related info is enough (always? or only north-up?) to provide a complete projection and geotransform, but there are also the set of GCPs. I've never checked to see if they always match to a good tolerance, and I don't know what GDAL does with the redundant info. >From your note, it sounds like GDAL prefers the GCP transform -- is that so? and I'm not sure that's the best option -- presumably the info in the header is exact? Why not prefer that? -Chris -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception chris.bar...@noaa.gov _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
