[postgis-devel] Geometry->Raster (rendering)

strk strk at keybit.net
Wed Jan 26 07:04:56 PST 2011


Hi Pierre,
today Norman was reporting a use case which seemed
to call for raster rendering: creation of an "heat" map,
that is a raster showing vectorial features occurrences.

My idea was you'd initialize an empty raster and iteratively
render each vector on top, with each vector adding some value
to the pixels.

Now, I was looking in the RASTER plan for such a "render-to-raster"
function but haven't found one. With the CHIP type I did make this
kind of interface:

  Draw(CHIP, geometry, operation)

Where 'operation' could be Set, Add, Multiply.

The code (the C part) is still in there (lwgeom_chip.c)
and works for points and lines (no polygons yet).

Now, question is... will such interface be available for RASTER
as well, or how else would one go to do that map ?

--strk;

  ()   Free GIS & Flash consultant/developer
  /\   http://strk.keybit.net/services.html



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