[Qgis-developer] Student Projects

[Manuel Massing]

Hi Andrew,


> ==Raster reproject on the fly==
> I found a few papers on fast computation methods for geodetic coordinates.
>  I would need to find a variety of raster data sets with which to test the
> performance and accuracy of the methods.

I suspect most of the overhead in a software-resampler like gdalwarp stems
from the image resampling step.

So implementing resampling using the GPU (e.g. using anisotropic texture
mapping) would go a big way towards improving performance.

Coordinate remapping could be implemented by selectively subdividing a 
triangle mesh, i.e. a scheme where edges with the highest midpoint 
approximation error are adaptively subdivided. Using this scheme, exact
coordinate remapping is attained at vertices (via the u/v texture
coordinates), and linearly interpolated inside triangles. It is analogous to
the linear approximation of coordinate transforms as implemented in gdalwarp.

Using more advanced pixel shaders, one could then also use higher-order
interpolation schemes to lower the required number of support points.

bye,

	Manuel