Hello Michele, I haven't tried myself, but have you seen Markus's blog from some time ago??
http://courses.neteler.org/processing-landsat-8-data-in-grass-gis-7-rgb-composites-and-pan-sharpening/ Maybe useful :) Best, Vero 2016-07-18 12:00 GMT-03:00 Michele Toma <[email protected]>: > Hi everyone, > > > > I was wondering if anyone had any suggestions or workarounds to the issue > that I am having with pansharpening Landsat imagery? My email below has the > steps that I took to attempt to pansharpen, but once I create a natural > color image and run the pansharpen tool, I end up with distorted colors. > Are there any other methods that I should try? > > > > Thanks in advance, > > > > Michele > > > > *From:* grass-user [mailto:[email protected]] *On Behalf > Of *Michele Toma > *Sent:* Wednesday, July 13, 2016 5:39 PM > *To:* [email protected] > *Subject:* [GRASS-user] Pansharpening Landsat 8 Imagery > > > > Hi everyone, > > > > I am having difficulty with pansharpening Landsat 8 imagery using this > tutorial: http://planet.qgis.org/planet/tag/landsat/. I am able to create > a natural color image, but the pansharpening results in images with > distorted colors. > > > > Here are the steps that I have followed: > > > > 1. Import all Landsat 8 bands to GRASS 7.0.4 > > a. r.in.gdal > input=C:\Users\Michele\Desktop\LC81100362016082LGN00\LC81100362016082LGN00_B1.TIF > output=LC81100362016082LGN00_B1 -k -e > > 2. Converted digital number data to reflectance using i.landsat.toar > > a. i.landsat.toar input=LC81100362016082LGN00_B > output=LC81100362016082LGN00_refl > metfile=C:\Users\Michele\Desktop\LC81100362016082LGN00\LC81100362016082LGN00_MTL.txt > sensor=oli8 date=2016-03-22 > > 3. Color balanced using i.colors.enhance for bands 4, 3, 2 as RGB > respectively > > a. i.colors.enhance red=LC81100362016082LGN00_refl4@Osaka > green=LC81100362016082LGN00_refl3@Osaka > blue=LC81100362016082LGN00_refl2@Osaka > > 4. Displayed RGB map using bands 4, 3, 2 (I get a really great > natural color image) > > 5. Pansharpened bands 4, 3, 2 using band 8 as the panchromatic band > with the IHS method > > a. i.pansharpen red=LC81100362016082LGN00_refl4@Osaka > green=LC81100362016082LGN00_refl3@Osaka > blue=LC81100362016082LGN00_refl2@Osaka > pan=LC81100362016082LGN00_refl8@Osaka output=LC81100362016082LGN00_ihs > method=ihs > > 6. Displayed RGB map with the “pansharpened” bands for 4, 3, 2 > > 7. Result: An image that is entirely gray (I found this link that > says to use i.fusion.hpf, but following those instructions, I get “'make' > is not recognized as an internal or external command, operable program or > batch file.” > http://gis.stackexchange.com/questions/111763/pan-sharpen-landsat-8-using-grass-7 > Am I supposed to use the GUI for this?) > > > > From searching online, I have found that the i.pansharpen module doesn’t > take 16 bit imagery (which Landsat imagery is) but rather 8 bit. I found > this link ( > http://gis.stackexchange.com/questions/39174/how-to-color-balance-false-composites-of-pan-sharpened-landsat-images-in-grass/67319#67319) > that says to rescale the image. I attempted this twice: > > > > 1. When I run it on the bands produced after running the > i.landsat.toar module, I get numbers such as min=-0.00813278402972343 and > max=1.58301384751301. After rescaling the images to 0-255 and proceeding > with step 3 I end up with an entirely white image. > > 2. However, if I rescale the original bands which all have ranges > of 0-65535, to 0-255, then pansharpen, the result is a washed out version > of the natural color image. I believe this has been pansharpened, but the > colors are off. I also attempted to color balance the pansharpened bands > but was unsuccessful as well. > > > > Am I rescaling the images incorrectly or is there another step I am > getting wrong? Any guidance would be greatly appreciated. > > > > Thank you, > > > > Michele Toma > > [email protected] > > www.airborne.aero > > > > [image: New Small2] > > > > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user >
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