Re: [GRASS-dev] Landsat 5TM pre-processing - histogram matching - problem

2015-05-11 Thread joanna mardas
Hey! All right :-). Try what I posted on [2015-05-04 22:14:41]: # if Reflectance 1, set to 1000, else round and multiply by 1000 r.mapcalc --o TopoCorr_B_Trimmed_DOS1_ToCR_${Band_No}_${SCENE} = if( TopoCorr.B.Trimmed.DOS1.ToCR.${Band_No}@${SCENE} 1, 1000, round( 1000 *

Re: [GRASS-dev] Landsat 5TM pre-processing - histogram matching - problem

2015-05-10 Thread Nikos Alexandris
* joanna mardas joanna.mar...@wp.pl [2015-05-10 02:28:02 +0200]: Hey! joanna, once again, the easy other way is posted in my first reply, I think. You just need to multiply with 1000, perform the histogram matching, then divide by 1000.0 to get back to floats. So I did that:

Re: [GRASS-dev] Landsat 5TM pre-processing - histogram matching - problem

2015-05-08 Thread Moritz Lennert
On 07/05/15 20:06, Nikos Alexandris wrote: Moritz: AFAIU, you could use the vibility in km instead of the aerosol optical depth. i.atcorr will then calculate optical depth based on a standard model. To get visibility find a meteorological station close to your image and get the info for the

Re: [GRASS-dev] Landsat 5TM pre-processing - histogram matching - problem

2015-05-07 Thread Nikos Alexandris
Nikos: If you go all the way from DN to Top-of-Atmosphere reflectances (via i.landsat.toar), then to Top-of-Canopy (via i.atcorr), you'll have floating point values ranging in [0, 1.0]. If you recode this back to 8-bit, you should consider whether there is an important loss of

Re: [GRASS-dev] Landsat 5TM pre-processing - histogram matching - problem

2015-05-07 Thread joanna mardas
Thanks Nikos! I'm not sure that for Landsat 5 the loss is so important, but you can visually compare an image recoded to 0-255 with the one coming out of i.landsat.toar... Nor am I sure about it. Landsat5 is 8-bit. But one should definitively consider it, and mention the decisions

Re: [GRASS-dev] Landsat 5TM pre-processing - histogram matching - problem

2015-05-05 Thread joanna mardas
Hello! It's me again :) If you go all the way from DN to Top-of-Atmosphere reflectances (via i.landsat.toar), then to Top-of-Canopy (via i.atcorr), you'll have floating point values ranging in [0, 1.0]. If you recode this back to 8-bit, you should consider whether there is an important loss

Re: [GRASS-dev] Landsat 5TM pre-processing - histogram matching - problem

2015-05-05 Thread Nikos Alexandris
* joanna mardas joanna.mar...@wp.pl [2015-05-05 00:19:02 +0200]: Hello! You both are my heros! Thank you Moritz and Nikos! r.recode worked :D I did i.histo.match on two test images and it looks fine. If you go all the way from DN to Top-of-Atmosphere reflectances (via

[GRASS-dev] Landsat 5TM pre-processing - histogram matching - problem

2015-05-04 Thread joanna mardas
Hello, I'm totally new user of GRASS and of course I have some problems. I want to do the pre-processing of Landsat (5TM) images (for further band composite, classification and NDVI) and I was using the tips from http://grasswiki.osgeo.org/wiki/LANDSAT#Pre-Processing I did the i.landsat.toar I

Re: [GRASS-dev] Landsat 5TM pre-processing - histogram matching - problem

2015-05-04 Thread Moritz Lennert
On 04/05/15 11:28, joanna mardas wrote: Hello, I'm totally new user of GRASS and of course I have some problems. I want to do the pre-processing of Landsat (5TM) images (for further band composite, classification and NDVI) and I was using the tips from

Re: [GRASS-dev] Landsat 5TM pre-processing - histogram matching - problem

2015-05-04 Thread Nikos Alexandris
joanna mardas wrote: Hello, Hi Joanna, I'm totally new user of GRASS and of course I have some problems. I want to do the pre-processing of Landsat (5TM) images (for further band composite, classification and NDVI) and I was using the tips from

Re: [GRASS-dev] Landsat 5TM pre-processing - histogram matching - problem

2015-05-04 Thread Nikos Alexandris
joanna mardas wrote: I have fragments of original landsat images imported to GRASS and i.histo.match works with them without any problems. Nikos Alexandris : That is so because i.histo.match, as Moritz notes below, support for 8-bit raster data. Correction: support is there for

Re: [GRASS-dev] Landsat 5TM pre-processing - histogram matching - problem

2015-05-04 Thread joanna mardas
Hello! You both are my heros! Thank you Moritz and Nikos! r.recode worked :D I did i.histo.match on two test images and it looks fine. So now the rest of bands, and then band composite and supervised classification (I've found nice tutorial on youtube, so I'm gonna follow it, or I will try