[gdal-dev] Raster to vector conversions....

[Joaquim Luis]

On 01-07-2014 21:07, William Hudspeth wrote:
> Hello,
>
> I am trying to find a method of converting a raster grid to a polygon 
> vector that does NOT aggregate adjacent pixels that share the same Z 
> value. In other words, I would like the output vector to be a grid of 
> polygons where the number of polygons is equal to the number of pixels 
> in the source raster file, and where the polygon attribute values 
> reflect the pixel Z value. The script gdal_polygonize does not seem to 
> be able to do this. Any other ideas on how this might be accomplished??
>
> Thanks, Bill

Hi, I'm not sure I got what you want do but see if this pseudo-algo works

1- create one mask with 1's at the cells with the values you want to 
compute a border off, and 0's for the others
2- compute and dump the 0.5 contour

How to do it? Sorry, I know only a GMT recipe but I'm sure that if this 
solves your problem others will tell how to do it with GDAL.

Joaquim