[GRASS-user] troubles with i.landsat.rgb and d.rgb

GRASS GRASS user
1

Hello-

I have used r.ing.dal to import different Landsat TIFF images, and am now
trying to superimpose red, green, and blue spectral bandsto get "real
colour" images.

I am under the impression that I need to use i.landsat.rgb to auto-balance
the colours of the LANDSAT images I am using. I am using a PC, and when I
run the command:

i.landsat.rgb red=020.020.2000.055_B30 green=020.020.2000.055_B20
blue=020.020.2000.055_B10

a microsoft windows window pops up that informs me " r.univar.exe has
stopped working- a problem caused the program to stop working correctly.
Windows will close the program and notify you if a solution is available".
As long as I continue to run the i.landsat.rgb command, this window
continues to pop up.

Have I made a mistake somewhere??

Also, once (if?) I do get i.landsat.rgb to work, will the map display window
automatically show me the superimposed images??

Also, I have tried just running d.rgb on the same images:

d.rgb red=020.020.2000.103_B30 blue=020.020.2000.103_B20
green=020.020.2000.103_B10

with results:

PNG: GRASS_TRUECOLOR status: TRUE

PNG: collecting to file: F:/grassdata/path20/PERMANENT/.tmp/412.0.ppm,

     GRASS_WIDTH=535, GRASS_HEIGHT=484

but nothing shows up in my map display window. How do I display the results
of this??

I am very new to GRASS, so any advice would be much appreciated. Thanks
very much for the help,

Renae Mackas
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2

Renae Mackas wrote:

I have used r.ing.dal to import different Landsat TIFF images, and am now
trying to superimpose red, green, and blue spectral bandsto get "real
colour" images.

I am under the impression that I need to use i.landsat.rgb to
auto-balance the colours of the LANDSAT images I am using.

you do not "need" to use i.landsat.rgb, it just helps brighten things up
if the image comes out rather dark. example:
  http://bambi.otago.ac.nz/hamish/grass/landsat/

I am using a PC,

does that mean you are running MS Windows? native or cygwin version?
(sorry to be overly pedantic, but consider that many run linux on a PC,
and that historically many/most? GRASS users use some flavour of Linux)

and when I run the command:
i.landsat.rgb red=020.020.2000.055_B30
   green=020.020.2000.055_B20
   blue=020.020.2000.055_B10

a microsoft windows window pops up that informs me " r.univar.exe has
stopped working- a problem caused the program to stop working correctly.
Windows will close the program and notify you if a solution is vailable".
As long as I continue to run the i.landsat.rgb command,
this window continues to pop up.

can you run "r.univar 020.020.2000.055_B10" from the command prompt?

Have I made a mistake somewhere??

don't really know. might be an install problem.

can you view the scene ok in QGIS? (www.qgis.org)

Also, once (if?) I do get i.landsat.rgb to work, will the map display
window automatically show me the superimposed images??

no. if you are currently viewing the layers you have to do a "hard"
redraw as the GUI isn't aware that the colors have changed behind its
back and the existing view may be partially cached.

Also, I have tried just running d.rgb on the same images:

d.rgb red=020.020.2000.103_B30 blue=020.020.2000.103_B20
green=020.020.2000.103_B10

if this is the native build d.rgb shouldn't work from the command prompt,
as there are no xmon to draw to (d.mon + UNIX's X-Windows). Instead use
the 'Add RGB or HIS layer' button from the GIS manager.
the cygwin version uses X-Windows (aka X11) and so allows xmons.

good luck,
Hamish

3

Thanks for your input, and sorry for the delayed response Hamish, I've been
away for the last while and haven't had much chance to work with Grass.

Hamish wrote:

Renae Mackas wrote:

I have used r.ing.dal to import different Landsat TIFF images, and am now
trying to superimpose red, green, and blue spectral bandsto get "real
colour" images.

I am under the impression that I need to use i.landsat.rgb to
auto-balance the colours of the LANDSAT images I am using.

you do not "need" to use i.landsat.rgb, it just helps brighten things up
if the image comes out rather dark. example:
  http://bambi.otago.ac.nz/hamish/grass/landsat/

The reason that I wanted to try and use i.landsat.rgb is that when I have
been doing r.composite with the Landsat images, the resulting composite
images come out with a coloured tinge to them (I am putting together
images of sea ice formations, and most r.composite images come out with a
pinkish/purple tinge). I thought I might be able to avoid this using
i.landsat.rgb. Perhaps this was an incorrect assumption?

I am using a PC, using the native version.

does that mean you are running MS Windows? native or cygwin version?
(sorry to be overly pedantic, but consider that many run linux on a PC,
and that historically many/most? GRASS users use some flavour of Linux)

Yes, I am using MS windows, using the native version

and when I run the command:
i.landsat.rgb red=020.020.2000.055_B30
   green=020.020.2000.055_B20
   blue=020.020.2000.055_B10

a microsoft windows window pops up that informs me " r.univar.exe has
stopped working- a problem caused the program to stop working correctly.
Windows will close the program and notify you if a solution is vailable".
As long as I continue to run the i.landsat.rgb command,
this window continues to pop up.

can you run "r.univar 020.020.2000.055_B10" from the command prompt?

Yes, I could run this.

Have I made a mistake somewhere??

don't really know. might be an install problem.

can you view the scene ok in QGIS? (www.qgis.org)

Also, once (if?) I do get i.landsat.rgb to work, will the map display
window automatically show me the superimposed images??

no. if you are currently viewing the layers you have to do a "hard"
redraw as the GUI isn't aware that the colors have changed behind its
back and the existing view may be partially cached.

How do I do a "hard" redraw to be able to see the result of i.landsat.rgb?
What I ultimately want is a mosaic image of multiple Landsat images. If I
do end up using i.landsat.rgb, do end up doing the "hard redraw" with my
final mosaiced image, or do I have to do it seperately with each image
that I want to put into the mosaic?

Also, I have tried just running d.rgb on the same images:

d.rgb red=020.020.2000.103_B30 blue=020.020.2000.103_B20
green=020.020.2000.103_B10

if this is the native build d.rgb shouldn't work from the command prompt,
as there are no xmon to draw to (d.mon + UNIX's X-Windows). Instead use
the 'Add RGB or HIS layer' button from the GIS manager.
the cygwin version uses X-Windows (aka X11) and so allows xmons.

I tried using the button, and it displayed well, thank you.

good luck,
Hamish

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