[GRASS-user] Fastest way to merge raster images in GRASS...

GRASS GRASS user
,
1

Good day,

I am very interested in finding the fastest way to merge raster images (or parts of an image) with GRASS. Now I am using r.patch, but unfortunately it is very slow for my problem.
Is there any other ways to merge raster data in GRASS?
Or may be it will be more fast to use GDAL functions directly? May be GDAL merge?

Has anyone done experiments with this kind of issues?

Thanks in advance!

2

Andranik Hayrapetyan wrote:

Good day,

Good evening/night,

I am very interested in finding the fastest way to merge raster images (or
parts of an image) with GRASS.

r.patch ?

Now I am using r.patch, but unfortunately it is very slow for my problem.

- GRASS-GIS version and Operating System please?
- How slow? How big is the region in which you are operating? ( check with
g.region -p)

You can/should match the region to the extent of all the raster to-be-merged
images, then r.patch, of course.

Is there any other ways to merge raster data in GRASS?

Maybe r.mapcalc?

Or may be it will be more fast to use GDAL functions directly? May be GDAL
merge?

Sure, you can build "mosaics" using gdal utilities. I guess you already have
had a look at <http://www.gdal.org/gdal_merge.html&gt;\.

Has anyone done experiments with this kind of issues?

r.patch always did/does its job inside GRASS.

Regards, Nikos