[GRASS-user] Mosaic Images

[Hamish]

Chethan wrote:
> When I try to mosaic landsat images(just one band) which
> belong to adjacent
> path-rows they do not mosaic properly. It appears as in the
> attached
> screenshot. I have tried changing the order of images but
> just the
> overlapping image changed. I have tried r.patch as well as
> i.image.mosaic
> with region encompassing both the scenes. However if I
> mosaic the same
> images in ERDAS Imagine there are no issues. Mosaiced 
> image will be simply
> perfect except for brightness differences. ERDAS also
> provides options like
> histogram matching to sort out such issues. So what is the
> way to mosaic
> images in GRASS? Also is there any way to use specify
> options like
> resampling, histogram matching in the process?
...
> http://osgeo-org.1803224.n2.nabble.com/file/n6108043/mosaic.png

[sorry about yahoo's linewrap]


the d.what.rast or the query tool to check to see if the black image
boundaries are in fact NULL, or if they are 0. If they are 0 use the
r.null module to set them to NULL, then try again.


Hamish