[GRASS-dev] wxGUI: supervised classification tool

Rashad M mohammedrashadkm at gmail.com
Mon Feb 11 21:25:41 PST 2013


Hi All,

As I discussed with markus Netler he pointed out the idea of having a pure
pixel identification module for GRASS GIS. This will be very helful for
spectral unmixing because pure pixels are found  in the corners of PCA
space and since PCA transformed its spatial position is lost. see my other
post "reg i.pca module" where I had discussion with Nikos, Markus and
others.

So the point is it needs an interactive plot. I had gathered all other
inputs for the module and planning to start coding next week. Since its gui
and interactive scatter plot comes as a part it. I would like to know if
there is anybody working on it. If not I can make it happen as a part of
this new module


On Fri, Dec 21, 2012 at 11:18 PM, Vaclav Petras <wenzeslaus at gmail.com>wrote:

> Hi Stepan,
>
> On 21 December 2012 16:53, stepan.turek <stepan.turek at seznam.cz> wrote:
> > Hi,
> >
> > yesterday I discussed some ideas on improvement of supervised
> classification
> > capabilities in GRASS with Martin and a remote sensing researcher, who is
> > working with proprietary software.
> >
> > We came up with suggestion that useful feature for GRASS would be
> > interactive scatter plot tool which would allow to highlight pixels
> > according to chosen areas in scatter plot and also in reverse way it
> would
> > allow to highlight corresponding points in scatter plot for chosen areas
> in
> > map window.
> > Also it would plot class ellipses for training areas.
> >
> > Useful and unique feature among GIS and Imaginary software would be
> scatter
> > plot 3D mode which would allow comparison of 3 bands.
> >
> If starting from scratch, Matplotlib seems to be the right option. It
> allows to interactively select data and also draw 3D plots. Data for
> scatterplot can be obtained by r.stats -g input=map1,map2. The result
> needs to be stored and used for searching coordinates and values (i.e.
> coordinates in scatterplot). Highlighting in plot according to click
> in the map is probably possible. The other way should be also
> possible, there are some click handler sin matplotlib. Highlighting in
> map - that's probably something for your (Stepan's) new graphical
> object API.
>
> However, there is also Bivariate Scatterplot Tool available from Map
> Display. It's able to display plots for pairs of maps. The plot is
> wxplot which is not so powerful as matplotlib. I am not sure if it
> could be used more interactively.
>
> Vaclav
>
> > Stepan
> >
> > ---------- Původní zpráva ----------
> > Od: Anna Kratochvílová <kratochanna at gmail.com>
> > Datum: 20. 12. 2012
> > Předmět: Re: [GRASS-dev] wxGUI: supervised classification tool
> >
> >
> > Hi,
> >
> > On Thu, Dec 20, 2012 at 9:52 AM, Markus Neteler <neteler at osgeo.org>
> wrote:
> >> Hi,
> >>
> >> while searching for the new i.class tool I have discovered
> >> the "supervised classification tool"
> >> in Imagery -> Classify Image -> Interactive input for supervised
> >> classification
> >>
> >> Nice! /edit: I now see that it *is* the
> >> http://grasswiki.osgeo.org/wiki/WxIClass
> >>
> > Right, wxIClass (perhaps g.gui.iclass in the future), available as
> > "Interactive input for supervised classification" from the menu, is
> > intended to be an i.class replacement.
> >
> >> I tried it with NC data and loaded the Landsat2002 group.
> >> Now I would expect that I can select channels for display from
> >> the group. Perhaps something with [x] checkboxes would be
> >> good. The existing "free" choice of maps should remain of course.
> >
> > That's reasonable, other suggestions are here:
> > http://trac.osgeo.org/grass/wiki/wxGUIDevelopment/wxIClass
> >
> >>
> >> When I then digitize, it nicely opens the class dialog, ok. Then,
> >> when running, it segfaults (entire wxGUI disappears, no error msg
> >> visible).
> >
> > There have been some changes three days ago which should fix this
> > crash. If you used the latest version, we have a problem.
> >
> >>
> >> Suggestion: It may also become the tool for i.smap, just a method
> >> dialog would be needed
> >>
> >>> Run Analysis
> >> - MaxLik: i.maxlik
> >> - SMAP: i.gensigset, i.smap
> >>
> >
> > yes, something like this is planned, Stepan is collecting these ideas
> now.
> >
> > We haven't touched this tool for some time, however Martin tried to
> > use it in class with students this week and he promised to report
> > bugs.
> >
> > Anna and Vaclav
> >
> >> to make it universal. However, great to have such a tool now.
> >>
> >> Markus
> >> _______________________________________________
> >> grass-dev mailing list
> >> grass-dev at lists.osgeo.org
> >> http://lists.osgeo.org/mailman/listinfo/grass-dev
> >
> >
> > _______________________________________________
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-- 
Regards,
   Rashad
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