[fdo-internals] RFC 65 Implement Resampling for GDAL Provider

[Frank Warmerdam]

Trevor,

I skimmed the patch.  I'm slightly uptight about the concept of
instantiating a warper for each tile.  In the "gdal/frmts/vrtwarped.cc"
code I believe I created the warper once for the whole virtual result and
then just invoked poWarper->WarpRegionToBuffer() on a per tile basis but
this does mean a fair amount of extra work.  Did you examine the approach
of just using VRTWarpedDataset?  I think that was the approach I used in
QGIS at one time in history for warped rasters.

One other nit, the following line is unlikely to work well on some systems:

snprintf(buf, 255,
"MEM:::DATAPOINTER=0x%p,PIXELS=%d,LINES=%d,BANDS=4,DATATYPE=Byte,PIXELOFFSET=4,LINEOFFSET=%d,BANDOFFSET=1",
 resampledBytes,
resampledXSize, resampledYSize, resampledXSize*4);

I found for maximum portability I had to do special stuff which is now
captured in the CPLPrintPointer() function.  You might want to consider
using it.

Best regards,
Frank

On Fri, Oct 12, 2012 at 1:14 PM, Trevor Wekel
<trevor_wekel at otxsystems.com>wrote:

>  Hello list,****
>
> ** **
>
> I would like to present “RFC 65 - Implement Resampling for GDAL Provider”
> for review and comment.  I would like to add this functionality to the
> future FDO 3.8 release.  The submitted code patch also works with FDO
> 3.7... (unofficially...)****
>
> ** **
>
> http://trac.osgeo.org/fdo/wiki/FDORfc65****
>
> ** **
>
> Regards,****
>
> Trevor****
>
> _______________________________________________
> fdo-internals mailing list
> fdo-internals at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/fdo-internals
>
>


-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam,
warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Software Developer
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/fdo-internals/attachments/20121012/d420df5b/attachment.html>