Jonathan I don't know about worldview, but with modis I wound up using multiple ranges
0:0,750:110,1500:160,3000:210,4750:240,6375:255 see <lut> in the vrt tutorial Brian On Thu, 2011-06-09 at 12:39 -0700, Jonathan Greenberg wrote: > Brian: > > > Thanks! Great solution, definitely saved me some time. The main > issue (in terms of doing this entirely within GDAL) is getting the > right scaling to make the image look good. I was able to figure out > the correct scale range within ENVI, and then apply the scales as you > suggested below. Nikos' suggestion to use rgb2pct makes me wonder if > there is some way to figure out the optimal scale (which, AFAIK, is > part of how rgb2pct is functioning) to apply to this image. > > > Incidentally, what I'm trying to do is load Worldview-2 data onto an > iPad 2 for use with the GISRoam mobile mapping app. Worldview-2 is > 16-bit per band, 8 band data, with a very high dynamic range (we have > snow in our image, so we have lots of VERY bright pixels which throw > off the adjustment if using -scale without any parameters). 99% > (100%?) of mobile mapping applications need 3-band data, usually with > only 8 bits per band. > > > Pushing forward, but if someone knows how to figure out an optimal set > of scale values to use within GDAL, please post the solution. > > > --j > > On Wed, Jun 8, 2011 at 9:45 PM, Brian Case <[email protected]> wrote: > Jonathan > > you can do scaling on individual bands. > > gdal_translate -b 1 -scale 0 5000 -ot Byte -of VRT infile > outfile1.vrt > gdal_translate -b 2 -scale 0 4000 -ot Byte -of VRT infile > outfile2.vrt > gdal_translate -b 3 -scale 0 3000 -ot Byte -of VRT infile > outfile3.vrt > > gdalbuildvrt -separate output.vrt outfile1.vrt outfile2.vrt > outfile3.vrt > > gdal_translate -of gtiff output.vrt output.tif > > > > for more complicated scaling you may need to hand write a vrt > > http://www.gdal.org/gdal_vrttut.html > > Brian > > > On Wed, 2011-06-08 at 19:31 -0700, Jonathan Greenberg wrote: > > Nikos and GDALers: > > > > > > This is CLOSE to what I'm looking to do, but I'm having a > hard time > > getting it working properly. Here's my input dataset > gdalinfo dump: > > > > > > *** > > > > > > Driver: ENVI/ENVI .hdr Labelled > > Files: > 10SEP10191223-M2AS-052377832030_01_P003_ps_gs_bl_tc.envi > > > 10SEP10191223-M2AS-052377832030_01_P003_ps_gs_bl_tc.hdr > > Size is 42255, 51712 > > Coordinate System is: > > GEOGCS["WGS 84", > > DATUM["WGS_1984", > > SPHEROID["WGS 84",6378137,298.257223563, > > AUTHORITY["EPSG","7030"]], > > TOWGS84[0,0,0,0,0,0,0], > > AUTHORITY["EPSG","6326"]], > > PRIMEM["Greenwich",0, > > AUTHORITY["EPSG","8901"]], > > UNIT["degree",0.0174532925199433, > > AUTHORITY["EPSG","9108"]], > > AUTHORITY["EPSG","4326"]] > > Origin = (-120.066479999999999,39.271554000000002) > > Pixel Size = (0.000004500000005,-0.000004500000005) > > Image Structure Metadata: > > INTERLEAVE=BAND > > Corner Coordinates: > > Upper Left (-120.0664800, 39.2715540) (120d 3'59.33"W, > > 39d16'17.59"N) > > Lower Left (-120.0664800, 39.0388500) (120d 3'59.33"W, 39d > > 2'19.86"N) > > Upper Right (-119.8763325, 39.2715540) (119d52'34.80"W, > > 39d16'17.59"N) > > Lower Right (-119.8763325, 39.0388500) (119d52'34.80"W, 39d > > 2'19.86"N) > > Center (-119.9714062, 39.1552020) (119d58'17.06"W, 39d > > 9'18.73"N) > > Band 1 Block=42255x1 Type=UInt16, ColorInterp=Undefined > > Band 2 Block=42255x1 Type=UInt16, ColorInterp=Undefined > > Band 3 Block=42255x1 Type=UInt16, ColorInterp=Undefined > > > > > > *** > > > > > > I need to end up with a Byte TIF image with good color > balance from > > this input. Running rgb2pct.py on this dataset just > outputted a > > "blank" (grey) image. Running gdal_translate -of GTiff -ot > Byte > > -scale [min] [max] worked somewhat, but its near impossible > to get > > this looking right, since the scaling I want to do differs > from band > > to band (e.g. if there any way to use -scale to adjust each > band > > separately)? Alternatively, how would I get rgb2pct.py > working on the > > above image correctly? Thanks! > > > > > > --j > > > > > > > > On Wed, Jun 8, 2011 at 4:10 PM, Nikolaos Hatzopoulos > > <[email protected]> wrote: > > why you don't try rgb2pct > http://www.gdal.org/rgb2pct.html? > > > > --Nikos Hatzopoulos > > > > > > On Wed, Jun 8, 2011 at 2:20 PM, Jonathan Greenberg > > <[email protected]> wrote: > > > > > > Folks: > > > > > > I am using a piece of software which is > relying on an > > older version of GDAL that doesn't have the > "fix" to > > deal with > 8 bit geotiffs (it is trying to > make a > > jpeg overlay but can't from a 16 bit image. > I think > > this is the issue: > > > http://trac.osgeo.org/gdal/wiki/TIFF12BitJPEG), but > > when I do a straight convert (-ot Byte) the > output > > image looks really washed out. Any hints > for getting > > the best quality output from a 16 bit to to > an 8 bit > > conversion of a Geotiff? > > > > > > --j > > > > -- > > Jonathan A. Greenberg, PhD > > Assistant Project Scientist > > Center for Spatial Technologies and Remote > Sensing > > (CSTARS) > > Department of Land, Air and Water Resources > > University of California, Davis > > One Shields Avenue > > Davis, CA 95616 > > Phone: 415-763-5476 > > AIM: jgrn307, MSN: [email protected], > Gchat: jgrn307 > > > > > > > > > > > _______________________________________________ > > gdal-dev mailing list > > [email protected] > > > http://lists.osgeo.org/mailman/listinfo/gdal-dev > > > > > > > > > > -- > > Jonathan A. Greenberg, PhD > > Assistant Project Scientist > > Center for Spatial Technologies and Remote Sensing (CSTARS) > > Department of Land, Air and Water Resources > > University of California, Davis > > One Shields Avenue > > Davis, CA 95616 > > Phone: 415-763-5476 > > AIM: jgrn307, MSN: [email protected], Gchat: jgrn307 > > > > > > _______________________________________________ > > gdal-dev mailing list > > [email protected] > > http://lists.osgeo.org/mailman/listinfo/gdal-dev > > > > > > > -- > Jonathan A. Greenberg, PhD > Assistant Project Scientist > Center for Spatial Technologies and Remote Sensing (CSTARS) > Department of Land, Air and Water Resources > University of California, Davis > One Shields Avenue > Davis, CA 95616 > Phone: 415-763-5476 > AIM: jgrn307, MSN: [email protected], Gchat: jgrn307 > > > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
