[GRASS-user] no nulls outside project map area
William Kyngesburye
woklist at kyngchaos.com
Fri Jun 5 16:52:32 EDT 2009
Ugh - tried it with GRASS 6.4 and I get the nulls. Looks like a GRASS
6.5 bug.
On Jun 5, 2009, at 3:43 PM, William Kyngesburye wrote:
> I started with a tiff image, in Albers projection. Imported in a
> new location in GRASS - the tiff region is rectangular with no nulls
> in the region, so the GRASS region follows the tiff region exactly.
>
> Then I projected to a latlong location. The tiff is off to one side
> of the central meridian, so the projected image appears rotated and
> stretched, as expected:
>
> <unprojected.png>
>
>
> But the the triangular areas outside the original tiff region are
> white, not null. My latlong region is larger than the image - I'm
> going to merge multiple tiled and overlapping tiffs - and there are
> nulls outside the extents of the projected area of the image.
>
> Is this expected behavior? I usually go from latlong to projected
> location, and the source latlong region is larger than the projected
> region so I don't see this.
>
> GRASS 6.5svn
-----
William Kyngesburye <kyngchaos*at*kyngchaos*dot*com>
http://www.kyngchaos.com/
"Oh, look, I seem to have fallen down a deep, dark hole. Now what
does that remind me of? Ah, yes - life."
- Marvin
More information about the grass-user
mailing list