[GRASSLIST:5484] GRASS image processing

GRASS GRASS user
1

Dear Grasslisters,

I'm going to do some image processing of Landsat and ASTER
Images. I'm a bit confused, because everybody in my environment
is using ErdasImagine. So, could anybody please tell me about
the capabilities and possibilities, pertaining to Image Processing Tools, provided by GRASS in comparison to ErdasImagine or ENVI.

Thank's a lot!

With best regards,

Grit

--
Grit Schuster, Environmental Scientist

Department of Physical Geography
Albert-Ludwigs Univeristy Freiburg
Werderring 4
D-79085 Freiburg

phone: +49-(0)761-2039124
fax: +49-(0)761-203-3596
email: grit.schuster@geographie.uni-freiburg.de
www: http://www.geographie.uni-freiburg.de/ipg/gkgl/gk.htm

2

From my experience, I think ERDAS is much more easier to use, more user

friendly. If you are comfortable w/ GRASS its the way to go (much more
powerful), but ERDAS is more intuitive (the Field Guide/ manual is also
really good). Don't know much about ENVI !

Dear Grasslisters,

I'm going to do some image processing of Landsat and ASTER
Images. I'm a bit confused, because everybody in my environment
is using ErdasImagine. So, could anybody please tell me about
the capabilities and possibilities, pertaining to Image Processing
Tools, provided by GRASS in comparison to ErdasImagine or ENVI.

Thank's a lot!

With best regards,

Grit

--
Grit Schuster, Environmental Scientist

Department of Physical Geography
Albert-Ludwigs Univeristy Freiburg
Werderring 4
D-79085 Freiburg

phone: +49-(0)761-2039124
fax: +49-(0)761-203-3596
email: grit.schuster@geographie.uni-freiburg.de
www: http://www.geographie.uni-freiburg.de/ipg/gkgl/gk.htm

3

I don't have much expeience with Erdas, but I have had limited exposure to ENVI. To my knowledge the tools available in ENVI for spectral unmixing are unmatched in any other tool. I know that some of that work can be done in GRASS in combination with a product I think called GOBI. In fact I believe Markus did some of that work for his PhD. In the case of GRASS however, these tools are not integrated into a simple easy to use package the way it is in ENVI.

I can't say anything about the other image processing functions in any of these tools.

T

On Sat, 22 Jan 2005 11:39:32 +0100
Grit Schuster <grit.schuster@geographie.uni-freiburg.de> wrote:

Dear Grasslisters,

I'm going to do some image processing of Landsat and ASTER
Images. I'm a bit confused, because everybody in my environment
is using ErdasImagine. So, could anybody please tell me about
the capabilities and possibilities, pertaining to Image Processing
Tools, provided by GRASS in comparison to ErdasImagine or ENVI.

Thank's a lot!

With best regards,

Grit

--
Trevor Wiens
twiens@interbaun.com

The significant problems that we face cannot be solved at the same
level of thinking we were at when we created them.
(Albert Einstein)

4

Grit,

I've used Imagine a bit and seen ENVI but not used it. Grass has fairly
complete image processing tools, especially in that image processing is
seamlessly integrated with high-end GIS and visualization rather than being
a separate program. This means a suite of raster manipulation tools,
including a map calculator and image fusion, can be applied to imagery. All
GRASS modules are scriptable, so that shell scripts (also perl or python for
the more sophisticated) can be written that automate many complex,
multi-step tasks and run in GRASS with a nice GUI.

A description of the dedicated image analysis modules in the current GRASS
6.0.0 beta1 distribution can be found at

<http://grass.itc.it/grass60/manuals/html60_user/imagery.html&gt;

You should also look at the much larger suite of raster processing modules
that can be applied to images. Descriptions can be found at

<http://grass.itc.it/grass60/manuals/html60_user/raster.html&gt;

Display options are found at
<http://grass.itc.it/grass60/manuals/html60_user/display.html&gt; including
histogramming.

N-dimensional visualization is available via the integrated NVIZ module
<http://grass.itc.it/gdp/nviz/nviz_toc.html&gt;\. NVIZ and GRASS 6 also support
true 3-D volumetric modeling and display (see
<http://grass.itc.it/grid3d/index.html&gt;\).

I'm hoping to finish a more up-to-date screenshot page by sometime next week
to show the current look of GRASS 6.

Several other very nice (and free software) tools for image manipulation
that are free are:
Multispec (Purdue & NASA <http://dynamo.ecn.purdue.edu/~biehl/MultiSpec/&gt;\),
Hypercube (US Army <http://www.tec.army.mil/Hypercube/&gt;\),
ImageJ (NIH <http://rsb.info.nih.gov/ij/&gt;\), and
GIMP <http://www.gimp.org/&gt;

Cheers,
Michael Barton

____________________
C. Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
PO Box 872402
Arizona State University
Tempe, AZ 85287-2402
USA

Phone: 480-965-6262
Fax: 480-965-7671
www: <www.public.asu.edu/~cmbarton>

On 1/22/05 3:39 AM, "Grit Schuster"
<grit.schuster@geographie.uni-freiburg.de> wrote:

Dear Grasslisters,

I'm going to do some image processing of Landsat and ASTER
Images. I'm a bit confused, because everybody in my environment
is using ErdasImagine. So, could anybody please tell me about
the capabilities and possibilities, pertaining to Image Processing
Tools, provided by GRASS in comparison to ErdasImagine or ENVI.

Thank's a lot!

With best regards,

Grit