I have a sequence of satellite images (e.g 1 in the north, other in the
center and other in south) that I want to merge in a single image. I found
three GRASS methodologies:
- r.series
- r.patch
- i.image.mosaic.
Which one is the best to perform what I need?
I'm not really familiar with i.image.mosaic, but r.patch would be the
one to use if you have three satellite images taken in sequence which
you wish to merge into a single image.
r.series is usually used to merge overlapping maps, r.patch to merge
adjoining maps.
to make r.patch easier, you can do:
g.region rast=map1,map2,map3
to extend the region settings to the outer bounds of all three maps.
> I have a sequence of satellite images (e.g 1 in the north, other in the
> center and other in south) that I want to merge in a single image. I
> found three GRASS methodologies:
> - r.series
> - r.patch
> - i.image.mosaic.
> Which one is the best to perform what I need?
Hamish:
I'm not really familiar with i.image.mosaic, but r.patch would be the
one to use if you have three satellite images taken in sequence which
you wish to merge into a single image.
r.series is usually used to merge overlapping maps, r.patch to merge
adjoining maps.
to make r.patch easier, you can do:
g.region rast=map1,map2,map3
to extend the region settings to the outer bounds of all three maps.
Something critical, if I am not wrong: the order of "map1,map2,map3" is
important (when patching overlaping maps). Check the r.patch manual.
Very good point… As far as I can see, the order is relevant in “overlapping pixels”.
About the i.image.mosaic, it was developed by Markus. I gave a look at the Script (Python version) and I’m not sure what is the advantage of this script against r.patch.
I have a sequence of satellite images (e.g 1 in the north, other in the
center and other in south) that I want to merge in a single image. I
found three GRASS methodologies:
r.series
r.patch
i.image.mosaic.
Which one is the best to perform what I need?
Hamish:
I’m not really familiar with i.image.mosaic, but r.patch would be the
one to use if you have three satellite images taken in sequence which
you wish to merge into a single image.
r.series is usually used to merge overlapping maps, r.patch to merge
adjoining maps.
to make r.patch easier, you can do:
g.region rast=map1,map2,map3
to extend the region settings to the outer bounds of all three maps.
Something critical, if I am not wrong: the order of “map1,map2,map3” is
important (when patching overlaping maps). Check the r.patch manual.
About the i.image.mosaic, it was developed by Markus. I gave a look at the
Script (Python version) and I'm not sure what is the advantage of this
script against r.patch.
I guess it's the convenience extending the colomap to all to-be-patched maps.