[postgis-users] line simplication

Daniel Morissette morissette at dmsolutions.ca
Wed Jan 8 08:21:38 PST 2003

"Eric L. Blevins" wrote:
> A simplification function that accepts the geometry and a factor of how much
> to simplify will be very usefull to anyone using applications like
> mapserver.
> With this function I think I could decrease the rendering time of my maps by
> an order of magnitude while still producing quality maps.

Just a quick note to let you know that MapServer already 'simplifies'
the shapes before passing them to the rendering code so the gain in
performance may not be as big as you expect.  With a simplify()
function at the database end you would slightly reduce the time to
transfer the shapes from PostGIS to MapServer and to package them as
shapeObj initially in MapServer, but you would not save any time in the
rendering code since MapServer already does its own simplification based
on the pixel size of the output image.

 Daniel Morissette               morissette at dmsolutions.ca
 DM Solutions Group              http://www.dmsolutions.ca/

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