[GRASS-dev] i.pansharpen and Landsat 8

[Nikos Alexandris]

On Wed, Oct 23, 2013 at 10:09 AM, Yann Chemin<ychemin at gmail.com>  wrote:

> >> Using L8 with i.pansharpen gives nodata output, is it assuming 8-bit
> >> datasets?


On 23/10/13 12:48, Markus Neteler wrote:

> > I didn't have such problems, see
> > http://courses.neteler.org/processing-landsat-8-data-in-grass-gis-7-rgb-co
> > mposites-and-pan-sharpening/


On Wednesday 23 of October 2013 15:13:48 Moritz Lennert wrote:

> In the first part of that tutorial, you run i.landsat.toar on the data.
> Could that make a difference ?

I (re-)tested here by using the same bands that were already converted to Top 
of Canopy Reflectance (based on DOS1). The outputs are not NULLs. However, I 
don't like the look of it, even after rebalancing.

--%<---
G70 [ mangroves_monitoring / bengalis_island_utm_48n @LC81260592013137LGN01 ] 
: ~ [12/134]
> r.info -r B.ToCR.DOS1.2
min=0.0279806868991949
max=0.0887139433548827
[Raster MASK present]

G70 [ mangroves_monitoring / bengalis_island_utm_48n @LC81260592013137LGN01 ] 
: ~ [13/135]
> !!:s/2/3
r.info -r B.ToCR.DOS1.3
min=0.162416309747371
max=0.826031487626996
[Raster MASK present]
G70 [ mangroves_monitoring / bengalis_island_utm_48n @LC81260592013137LGN01 ] 
: ~ [14/136]
> !!:s/3/5
r.info -r B.ToCR.DOS1.5
min=0.12789699116205
max=1.01093695749278
[Raster MASK present]
G70 [ mangroves_monitoring / bengalis_island_utm_48n @LC81260592013137LGN01 ] 
: ~ [15/137]
> !!:s/5/8
r.info -r B.ToCR.DOS1.8
min=0.156489372272025
max=0.839101471394332
[Raster MASK present]
--->%--

and

--%<---
for Sharp in `g.mlist rast pat=sharpen_ToCR*`  ;  do r.info "${Sharp}" -r  ;  
done

min=0
max=0
min=0
max=2
min=0
max=2
[Raster MASK present]
--->%--

I think this is a Floating Point vs. Integers values issue here (if I recall 
from the discussion in ticket #2048).

Nikos