Re: [GRASS-user] Mosaic Images
On Tue, Mar 8, 2011 at 10:45 AM, Hamish wrote: > 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. As an alternative, you can use r.clump2 from GRASS-Addons and flood-fill areas (here, the "black" boundary" using the coordinate parameter. Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Mosaic Images
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 ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] Mosaic Images
Greetings! 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? Thanks and regards, Chethan S. http://osgeo-org.1803224.n2.nabble.com/file/n6108043/mosaic.png -- View this message in context: http://osgeo-org.1803224.n2.nabble.com/Mosaic-Images-tp6108043p6108043.html Sent from the Grass - Users mailing list archive at Nabble.com. ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
