Dear List,
I am new user for Grass GIS. I have some questions regarding Jpg or tiff import. When I use r.in.gdal which created 3 separate files as rgb. Then I use r.patch to combine rgb. After that i.point and i.rectify. From this i have to digitize river, stream, road, etc. So my question is as follow:
Can i remove unrectified former 3 seperate rgb files?
Is there any module to import without creating rgb because this increase the memory usage? I have to import more than hundreds of scanned Jpg, tiff.
Can i crop the imported image without using other image software such as gimp or photoshop, etc?
Thanks for any hint
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U Kyaw Moe Aung, Staff Officer
Planning & Statistics Division, Forest Department, Director General’s Office
Nay Pyi Taw, Ph:095-67-405016, Fax: 095-67-405016
Dear List,
I am new user for Grass GIS. I have some questions regarding Jpg or tiff import. When I use r.in.gdal which created 3 separate files as rgb. Then I use r.patch to combine rgb. After that i.point and
What you probably want here is r.composite. It re-creates the colored raster.
i.rectify. From this i have to digitize river, stream, road, etc. So my question is as follow:
Can i remove unrectified former 3 seperate rgb files?
Yes, after r.composite you can remove them.
Is there any module to import without creating rgb because this increase the memory usage? I have to import more than hundreds of scanned Jpg, tiff.
Imported three-band tiffs will always create three separate rasters. But you can script this to loop thru your 100’s of tiff’s to import, recreate the colored raster, then delete the *.red, *.green and *.blue at each loop.
Can i crop the imported image without using other image software such as gimp or photoshop, etc?
Yes. Just set the grass region to the area you want, and run:
r.mapcalc cropped_raster=original_raster
That creates a copy of the original, cropped to the current region.
BTW, this can also be done in advance with gdal.
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Micha Silver
Arava Development Co. +972-52-3665918
[http://www.surfaces.co.il](http://www.surfaces.co.il)