[Gdal-dev] projected bounding box

Jonathan Coles jonathan at intevation.de
Mon Jul 14 12:51:46 EDT 2003

On Mon, 2003-07-14 at 18:39, Ed McNierney wrote:
> This is a tricky problem to solve in a general case, 
> and has been the source of a number of software bugs 
> I've met along the way!

Hopefully, in the future, not with Thuban ;)

> To do it right, you need to take EACH POINT along
> each of the edges of the output bounding box (rectangle)
> and reproject it back into the source projection.  For 
> each edge you calculate the appropriate minimum/maximum 
> value in the input projection.

I was afraid of this response.

> it might be easier for you to take your specific application and calculate
> a "buffer" value.  
> This is obviously a special-case solution, but it's 
> probably a lot simpler and faster than trying to solve 
> the general problem.

That's the problem, this isn't a special case situation. It should
really work with any projection anywhere on the globe. It certainly is
something for me to think about though. Perhaps I can come up with a way
that will guarantee a good buffer value. Thanks for your thoughts.


 Jonathan Coles                                jonathan at intevation.de
 Intevation GmbH                             http://www.intevation.de

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
Url : http://lists.osgeo.org/pipermail/gdal-dev/attachments/20030714/c107a4d7/attachment.bin

More information about the Gdal-dev mailing list