Le mardi 15 juillet 2014 20:33:32, Michael Aschenbeck a écrit : > Hello, > > I'm trying to follow the warp tutorial (http://www.gdal.org/warptut.html) > to do a general warp. However, I'm not getting any good results. > > I first recreated the example in the warp tutorial by first implementing > the bottom portion modified to output an RGB image, then implementing the > top portion with GDALGenImgProjTransform as written. This worked fine. > > Second, I tried to create my own, most basic, transformation: > > int identityTransform(void *pTransformerArg,int bDstToSrc, int nPointCount, > double *x, double *y, double *z, int *panSuccess) > { > return 1; > } > > i.e. it does not modify any coordinates. So I changed: > eErr = GDALSuggestedWarpOutput( poDataset, GDALGenImgProjTransform, > hTransformArg, adfDstGeoTransform, &nPixels, &nLines ); > to: > GDALTransformerFunc myTransformer = &identityTransform; > eErr = GDALSuggestedWarpOutput( poDataset, myTransformer, hTransformArg, > adfDstGeoTransform, &nPixels, &nLines ); > > > and > //psWarpOptions->pfnTransformer = GDALGenImgProjTransform; > to: > psWarpOptions->pfnTransformer = myTransformer; > > I expect to get the same image back but all i get is two vertical lines > with unreasonable georeferenced coordinates. I'm hoping someone can show > me where I'm going wrong, or guide me to an example of a custom > GDALTransformerFunc to use as a template. > > Thank you in advance for any help you can give!
Why not using gdalwarp directly, or re-using its source code ? -- Geospatial professional services http://even.rouault.free.fr/services.html _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
