[GRASS-user] mosaicing classified images

[maning sambale]

But the landsat images are of different dates and in some case different years.

I found some mosaicing debates here:
http://www.faqs.org/faqs/sci/Satellite-Imagery-FAQ/part3/section-14.html

2 schools of thought appear:
1. Mosaic image then classify
2. Classify individual images then mosaic

I am following the great grass developer Michael Shapiro's (is he the
grass developer?) advice on option 2.

On Wed, Jan 21, 2009 at 7:16 PM, Markus Neteler <neteler at osgeo.org> wrote:
> On Wed, Jan 7, 2009 at 4:04 AM, maning sambale
> <emmanuel.sambale at gmail.com> wrote:
>> Hi,
>> I have a series of classified rasters from different landsat images
>> (various dates).  I want to moasic/stitch them to a one raster.  The
>> problem is there are subtle differences in the classified output. Any
>> advise in mosaicing them?
>
> (I am afraid that it is easier to first mosaic (e.g., with OSSIM), then
>  do the classification...)
>
> You could vectorize the raster areas and then try some SQL
> magic to match close polygons. Also v.clean to remove tiny
> areas from the map if needed.
>
> Markus
>



-- 
cheers,
maning
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