Hi,
Please can someone assist me in viewing SPOT5 imagery in "normal" colours.
I've got some SPOT5 imagery that I want to convert to (close to) real
colour, and am told that:
Band 1 is green
Band 2 is red
Band 3 is NIR
band 4 is shortwave IR
* I found two different methods* for creating pseudo-Blue. (or pseudo RGB)
Blue = 0.7*Green + 0.24*Red - 0.15*NIR
* and the other was:*
Blue = 0.85*Band 1 - 0.15*Band3
Green = 0.65*Band 1 + 0.35*Band 3
Red = Band 2
so they are fairly similar (assuming the second one has the same band order
as my image).
I use gdal_calc.py to create the 3 separate band-tif images and then
gdal_merge.py to create my two variants of the RGB tiffs.
When I open these images in QGIS 2.0.1, they are brownish rather that
pseudo RGB
I have set the 'style' to multiband colour, "loaded" the min/max values and
then set contrast to "Stretch to Min/Max".
I have also tried various combinations of the 3 bands in case gdal_merge.py
doesn't honour file-order to band order.
Can anyone offer a solution to this issue?
Thanks and regards,
Zoltan.
===========================================
Zoltan Szecsei PrGISc [PGP0031]
Geograph (Pty) Ltd.
GIS and Photogrammetric Services
===========================================
* FYI My script is as follows:*
# 20140307 - Zls do bandmath to create create synthetic RGB
TIFin="3229AA"
gdal_calc.py -A ${TIFin}.tif --A_band=1\
-B ${TIFin}.tif --B_band=2\
-C ${TIFin}.tif --C_band=3\
-D ${TIFin}.tif --D_band=4\
--outfile=${TIFin}r.tif\
--overwrite\
--calc="B"
#
gdal_calc.py -A ${TIFin}.tif --A_band=1\
-B ${TIFin}.tif --B_band=2\
-C ${TIFin}.tif --C_band=3\
-D ${TIFin}.tif --D_band=4\
--outfile=${TIFin}g.tif\
--overwrite\
--calc="A"
# --calc="(A*0.65)+(C*0.35)"
#
gdal_calc.py -A ${TIFin}.tif --A_band=1\
-B ${TIFin}.tif --B_band=2\
-C ${TIFin}.tif --C_band=3\
-D ${TIFin}.tif --D_band=4\
--outfile=${TIFin}b.tif\
--overwrite\
--calc="(A*0.7)+(B*0.24)-(C*0.14)"
# --calc="(A*0.85)-(C*0.15)"
#
rm -f ${TIFin}rgbx.tif > /dev/null 2> /dev/null
gdal_merge.py -o ${TIFin}rgbx.tif\
-separate\
${TIFin}r.tif\
${TIFin}g.tif\
${TIFin}b.tif
--
--
Check the OTB FAQ at
http://www.orfeo-toolbox.org/FAQ.html
You received this message because you are subscribed to the Google
Groups "otb-users" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/otb-users?hl=en
---
You received this message because you are subscribed to the Google Groups
"otb-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
