Re: Rasters, Vectors and spatial databases
Jose Gomez-Dans <[email protected]>
| Newsgroups | gmane.comp.gis.freegis |
|---|---|
| Message-ID | <[email protected]> |
Hi Frank, Thank you very much for your prompt reply. It is really very appreciated! > OGR, the vector side of GDAL/OGR can support Oracle Spatial, > so in if you build it carefully to include Oracle support you could use > OGR to extract the polygon(s) from Oracle. Either at the commandline > with ogr2ogr, using the C++ API or perhaps from Python. OK, this looks like a doable possibility. There's also a C interface to OGR, is there not? > I'm not sure what you have been using to rasterize he polygons so > far, but I do know of folks doing this sort of thing with MapServer. > The whole process could also be automated in GRASS which includes > GDAL raster access and OGR vector access as well as good polygon > rasterization for masking, and sophisticated sorts of raster analysis. > You might need to be somewhat handy with shell scripting to automate > it in GRASS. I think my colleagues working ont he GIS side have used some propietary software, but rasterisation is problematic for a number of reasons, and needs a fair bit of user input. Ideally, I would like to have the polygon edges, and select the pixel values which lie within said polygon. I have coded similar algorithms in the past, but have found that my implementation was *ahem* not optimal :), and I was thinking that there ought to be a better implementation. OSSIM has an implementation (see <http://www.remotesensing.org/doxygen/ossim/classossimPolygon.html#a27>), so this could be re-implemented (given it is free software) for our purposes. I was actually wondering whether GDAL and OGR are connected somehow. Again, thank you for your comments, José