[GRASS-user] unexpected i.pansharpen results

[Nikos Alexandris]

Nikos Alexandris wrote:

[chewed up message by the "System" :D  -- apologies for re-posting!]


# 4)  i.pansharpen -- all of them, three methods -- from my history

### Brovey

   18  31.Jul.13 [ 15:54:36 ] i.pansharpen sharpen=brovey pan=Pan_Radiance 
ms1=Blue_Radiance ms2=Green_Radiance ms3=Red_Radiance 
output=sharp_brovey_Radiance

   19  31.Jul.13 [ 15:54:46 ] i.pansharpen sharpen=brovey pan=Pan_ToAR 
ms1=Blue_ToAR 
ms2=Green_ToAR ms3=Red_ToAR output=sharp_brovey_ToAR

   24  31.Jul.13 [ 15:59:16 ] i.pansharpen sharpen=brovey pan=Pan_DNs 
ms1=Blue_DNs 
ms2=Green_DNs ms3=Red_DNs output=sharp_brovey_DNs


### PCA

   59  31.Jul.13 [ 16:09:53 ] i.pansharpen sharpen=pca pan=Pan_DNs 
ms1=Blue_DNs 
ms2=Green_DNs ms3=Red_DNs output=sharp_pca_DNs

   60  31.Jul.13 [ 16:22:03 ] i.pansharpen sharpen=pca pan=Pan_Radiance 
ms1=Blue_Radiance 
ms2=Green_Radiance ms3=Red_Radiance output=sharp_pca_Radiance

   61  31.Jul.13 [ 16:27:28 ] i.pansharpen sharpen=pca pan=Pan_ToAR 
ms1=Blue_ToAR 
ms2=Green_ToAR ms3=Red_ToAR output=sharp_pca_ToAR


### IHS

   62  31.Jul.13 [ 16:35:12 ] i.pansharpen sharpen=ihs pan=Pan_ToAR 
ms1=Blue_ToAR 
ms2=Green_ToAR ms3=Red_ToAR output=sharp_ihs_ToAR

   63  31.Jul.13 [ 16:37:21 ] i.pansharpen sharpen=ihs pan=Pan_Radiance 
ms1=Blue_Radiance 
ms2=Green_Radiance ms3=Red_Radiance output=sharp_ihs_Radiance

   64  31.Jul.13 [ 16:39:32 ] i.pansharpen sharpen=ihs pan=Pan_DNs 
ms1=Blue_DNs 
ms2=Green_DNs ms3=Red_DNs output=sharp_ihs_DNs



# 5) Let's look at the numbers

for SHARP in `g.mlist rast pat=sharp*`; do r.info -mr ${SHARP}; done

min=36.2130177514793
max=153
title= (sharp_brovey_DNs_blue)

min=0
max=112.211538461538
title= (sharp_brovey_DNs_green)

min=0
max=107.968559837728
title= (sharp_brovey_DNs_red)

min=7.93864844473524
max=102.4232751775
title= (sharp_brovey_Radiance_blue)

min=0
max=87.5889521289036
title= (sharp_brovey_Radiance_green)

min=0
max=74.435557812593
title= (sharp_brovey_Radiance_red)

min=0
max=0.398724812575096
title= (sharp_brovey_ToAR_blue)

min=0
max=0.335289700449259
title= (sharp_brovey_ToAR_green)

min=0
max=0.476377949923749
title= (sharp_brovey_ToAR_red)

min=0
max=255
title=Image blue (sharp_ihs_DNs_blue)

min=0
max=255
title=Image green (sharp_ihs_DNs_green)

min=0
max=255
title=Image red (sharp_ihs_DNs_red)

min=0
max=255
title=Image blue (sharp_ihs_Radiance_blue)

min=0
max=254
title=Image green (sharp_ihs_Radiance_green)

min=0
max=254
title=Image red (sharp_ihs_Radiance_red)

min=0
max=2
title=Image blue (sharp_ihs_ToAR_blue)

min=0
max=2
title=Image green (sharp_ihs_ToAR_green)

min=0
max=2
title=Image red (sharp_ihs_ToAR_red)

min=177.072681268903
max=490.188522572706
title= (sharp_pca_DNs_blue)

min=174.855236596567
max=415.384343723085
title= (sharp_pca_DNs_green)

min=-71.4712772318356
max=390.53877906274
title= (sharp_pca_DNs_red)

min=38.0505369148222
max=189.658927814102
title= (sharp_pca_Radiance_blue)

min=24.8653625573439
max=215.672403116314
title= (sharp_pca_Radiance_green)

min=-13.7969488642255
max=113.557246501694
title= (sharp_pca_Radiance_red)

min=0.0506311311052859
max=0.660054986167671
title= (sharp_pca_ToAR_blue)

min=0.0146679903931977
max=0.832078269086436
title= (sharp_pca_ToAR_green)

min=-0.0646181045289202
max=0.451095521435642
title= (sharp_pca_ToAR_red)



At least for some of the above results, it is obvious that something isn't 
right.



# 6)  I use the script copy-pasted in ... the next message... in G64 (...I 
wish I could use frames in G7 :-p) to get some overviews, without and with 
"i.landsat.rgb -p"

Will upload screenshots uploaded in trac -- if possible.



Summary

In almost all -- actually, in all of them! -- there are NULL cells introduced 
there where they did not exist before.  I don't use a MASK. I have set up the 
region before running i.pansharpen to match the extent of the Red band, for 
example (resolution is taken care by the module).


Nikos