[gdal-dev] Polygonize from C# ?

[Jay Jennings]

I see, thanks.  But since I have satellite images, this part of the doc is alarming: "...For non-thematic raster data (such as satellite images) 
the result will essentially be one small polygon per pixel, and memory and output layer sizes will be substantial. The algorithm is primarily 
intended for relatively simple thematic imagery, masks, and classification results".

I just want one polygon enclosing the non-zero pixels (or alternatively, enclosing the zero pixels, then I could do a geometric 
difference).  Is there any way to trick the method into doing that, to maybe avoid the heavy resource needs ?


-----Original Message-----
From: Even Rouault [mailto:even.rouault at mines-paris.org] 
Sent: Friday, April 22, 2011 11:45 AM
To: Jay Jennings
Cc: gdal-dev at lists.osgeo.org
Subject: Re: [gdal-dev] Polygonize from C# ?

Selon Jay Jennings <Jennings.Jay at geoeye.com>:

Generally, refering to the C/C++ doc is a good way of finding the info :

See http://gdal.org/gdal__alg_8h.html#3f522a9035d3512b5d414fb4752671b1

> Hi list,
> Can anyone point to any guidance or (preferably) examples on using
> GDAL.Polygonize() with C# bindings ?  I see what the interface is, but there
> are some unexplained parameters, e.g. "string[] options".
>
> My eventual goal is to open a raster and produce a WKT POLYGON string
> enclosing the "good" (non-NoData) area of the raster.  Thanks.
>
> .........................................................
> Jay Jennings
> Senior Software Developer
> (NASDAQ: GEOY)
> jennings.jay at geoeye.com
>
>
>
>
>