My question is, when tiles are merged in GRASS using a virtual mosaic created with gdalbuildvrt, will transparent map collars be preserved? I see the man page for r.external talks about the requirement to build a mask or use r.mapcalc, but I don’t understand how I would apply that to a virtual mosaic. Is it possible?
Would a certain file format handle transparent border collars better than others?
Note that I already have all my tiles as GRASS rasters in my current location, alas I tried using r.patch running in parallel for the job first but it pretty much choked on the task. My attempt was terminated due to a power outage after running several weeks trying to create around 0.5 terrapixel mosaic.
Any suggestions how to best build a mosaic would be super appreciated!
On Dec 24, 2014, at 5:10 PM, Jeshua Lacock <jeshua@3DTOPO.com> wrote:
I was following along the Large raster data processing wiki with great interest:
My question is, when tiles are merged in GRASS using a virtual mosaic created with gdalbuildvrt, will transparent map collars be preserved? I see the man page for r.external talks about the requirement to build a mask or use r.mapcalc, but I don’t understand how I would apply that to a virtual mosaic. Is
It appears that GDAL_TIFF_INTERNAL_MASK may be just what I need to use. I wonder if that option is respected using r.external? Thanks!
On Thu, Dec 25, 2014 at 2:20 AM, Jeshua Lacock <jeshua@3dtopo.com> wrote:
On Dec 24, 2014, at 5:10 PM, Jeshua Lacock <jeshua@3DTOPO.com> wrote:
I was following along the Large raster data processing wiki with great interest:
My question is, when tiles are merged in GRASS using a virtual mosaic created with gdalbuildvrt, will transparent map collars be preserved? I see the man page for r.external talks about the requirement to build a mask or use r.mapcalc, but I don’t understand how I would apply that to a virtual mosaic. Is
It appears that GDAL_TIFF_INTERNAL_MASK may be just what I need to use. I wonder if that option is respected using r.external? Thanks!
I suppose that would apply to r.external.out as it seems to be related
to the creation of GeoTIFF (see http://www.gdal.org/frmt_gtiff.html).
On Dec 26, 2014, at 2:54 PM, Markus Neteler <neteler@osgeo.org> wrote:
I suppose that would apply to r.external.out as it seems to be related
to the creation of GeoTIFF (see http://www.gdal.org/frmt_gtiff.html).
Hi Markus,
Excellent, thank you for the tip!
Note I tried again using r.patch.many with a smaller batch last night (333 billion pixel mosiac) and it ran *much* better, but I think it is stuck now.
The “Bytes Read” has been going up continuously for the r.patch processes, but the bytes written hasn’t changed in over 8 hours and appears stuck at 57%. I think I can use r.patch.many for the job but I will have to break it into smaller sub-mosiacs first.
If I understand importing a virtual mosaic correctly, I suspect using r.external with a virtual mosaic is the best way to accomplish the task at hand, but I welcome any advice!
