[GRASSLIST:122] Re: making a "true-color" landsat composite

[Dylan Beaudette]

Thanks again Markus:

your new i.landsat.rgb script did wonders on these images!

examples:

original made with r.composite:
http://casoilresource.lawr.ucdavis.edu/drupal/node/217

new one made with i.landsat.rgb:
http://casoilresource.lawr.ucdavis.edu/drupal/node/216

Cheers!

Dylan

On 3/14/06, Dylan Beaudette <dylan.beaudette at gmail.com> wrote:
> Ian,
>
> Thanks for the pointers. In the past, I was not performing any
> "enhancements"
> to the landsat scenes as there were so many of them, and they looked good
> enough. However with Markus' latest script, I think that I will re-compile
> arizona! good thing that I hadn't started on Nevada yet!
>
> Cheers,
>
> Dylan
>
> On Tuesday 14 March 2006 12:44 pm, Ian MacMillan wrote:
> > Dylan, I am not sure if you have this problem, but you might want to
> > watch out with the colors when you patch landsat tiles together.  The
> > colors tend to get screwy since the the shots were each taken at
> > different times of day, different days of the year, etc.  I have found
> > that it is best to enhance each tile separately, then patch them
> > together at the end, rather than patching all band 1's, all band 2's
> > etc.  You probably already knew this, but thought I would add my two
> > cents.
> >
> > -Ian
> >
> > On Mar 14, 2006, at 10:04 AM, Dylan Beaudette wrote:
> > > Markus,
> > >
> > > Nice images!
> > >
> > > a couple things:
> > >
> > > 1. the link at the top of the page had some interesting polar plots.
> > > For hard copy I found that ps.rose in the GMT suite produces excellent
> > > results as well:
> > > http://169.237.35.250/~dylan/NPS/day100.png
> > >
> > > 2. the color boost technique -- is your script available on the GRASS
> > > wiki somewhere, or in the grass scripts dir in a recent CVS branch?
> > >
> > > This looks like it will do the trick, now the only problem is that I
> > > have just put together the entire state of Arizona with the poor
> > > looking imagery!
> > >
> > > thanks for the tips,
> > >
> > > Dylan
> > >
> > > On 3/14/06, Markus Neteler <neteler at itc.it> wrote:
> > >> Dylan Beaudette wrote:
> > >>> Hi everyone,
> > >>>
> > >>> I was working on constructing some "true color" landsat composite
> > >>> images today
> > >>> from bands 3,2,1 -- and came across some strange inconsistencies.
> > >>> Data from
> > >>> one source produces "nice" true color images:
> > >>>
> > >>> http://casoilresource.lawr.ucdavis.edu/drupal/node/211
> > >>>
> > >>> whereas, another source produces somewhat muddy true color
> > >>> composites. I tried
> > >>> playing a bit with an equalized grey colormap for each band via
> > >>> r.colors
> > >>> color=grey.eq with the following results:
> > >>>
> > >>> http://casoilresource.lawr.ucdavis.edu/drupal/node/215
> > >>>
> > >>>
> > >>> Does anyone have any tips on how to tweak color ramps for the
> > >>> various bands so
> > >>> as to get a better looking "true color" composite?
> > >>
> > >> how do you like this LANDSAT:
> > >>  http://mpa.itc.it/markus/grass61/demos/
> > >>  -> LANDSAT 7 color boost
> > >> ?
> > >>
> > >> Markus
> >
> > -------------------------------------------------------------
> > This message has been scanned by Postini anti-virus software.
>
> --
> Dylan Beaudette
> Soils and Biogeochemistry Graduate Group
> University of California at Davis
> 530.754.7341
>
>