[Gdal-dev] GDAL data model, caching, GDALProjDef

[Jim Julian]

Hi Derrick,

    Without the use of an (usually) expensive GIS program you would have to
improvise. You may be better off treating the data in image form. Use GDAL
to convert a DEM for the same quadrangle as your topo to a GeoTiff and
resample to the same SCALE (not the SIZE, check the world files). This will
make the DEM a template with which you can perform unions/intersections
etc. Think of the images as arrays then this will make more sense. You still
need to write or find the software to do these operations, but I don't believe
there is much difficulty. Python has an imaging library(PIL) which might be
of some help.

                                                                   Jim Julian

At 02:08 PM 2/16/03 -0500, you wrote:

>1) Is there a way I'm overlooking to decollar collared maps (in GeoTIFF
>form) or is it expected that an external program would be used for this? I
>understand that the georeferencing is insufficient to know where the image
>corners are, but I have other data which can be used for this.