Hi Frank, thx for very rapid response. gdal_merge.py now work and the result is intellegible.
testing the result , I notice the result is a 256 color image. Instead the starting image was true CCITTFax4 raster. This mean a huge dimension of files. Is possible to have a real Tiff4 (1 bit color) image as result ? Thx, Andrea. 2011/9/2 Frank Warmerdam <warmer...@pobox.com> > Andrea, > > I think the problem is that these are one bit files with > a black/white color table and by default gdal_merge.py > does not copy the color table. If you add the -pct > switch it should do so. > > I imagine the result file does have pixels with values of > zero and one, but you won't see them as different in > most viewers. > > Best regards, > > On Fri, Sep 2, 2011 at 2:40 PM, Andrea Peri <aperi2...@gmail.com> wrote: > > Hi, > > I need to merge some Tiff4 (bw) raster and obtain 1 only more big tiff4 > > raster. > > > > I'm try-ing this with gdal_merge.py > > and using a comand like this: > > > > python gdal_merge.py -o ../raster/216.tif -n 1 -ot Byte > > ../raster/10k/216*.tif > > > > Unfortunately the resulted raster is intellegible (the input raster was > all > > clearly visible). > > It is an all black image :( > > > > I tried also with option "-n 0" but the result is the same. > > > > I analyze the input raster using gdalinfo, and the result is this. > > > > ------------------ > >>gdalinfo.exe ../raster/10k/216100.tif > > Driver: GTiff/GeoTIFF > > Files: ../raster/10k/216100.tif > > ../raster/10k/216100.tfw > > Size is 10065, 10049 > > Coordinate System is: > > LOCAL_CS["unnamed", > > UNIT["unknown",1]] > > Origin = (1561222.860009765700000,4927094.449960937700000) > > Pixel Size = (0.500000000000000,-0.500000000000000) > > Metadata: > > AREA_OR_POINT=Point > > TIFFTAG_RESOLUTIONUNIT=1 (unitless) > > TIFFTAG_SOFTWARE=Arc/Info > > TIFFTAG_XRESOLUTION=2 > > TIFFTAG_YRESOLUTION=2 > > Image Structure Metadata: > > COMPRESSION=CCITTFAX4 > > INTERLEAVE=BAND > > MINISWHITE=YES > > Corner Coordinates: > > Upper Left ( 1561222.860, 4927094.450) > > Lower Left ( 1561222.860, 4922069.950) > > Upper Right ( 1566255.360, 4927094.450) > > Lower Right ( 1566255.360, 4922069.950) > > Center ( 1563739.110, 4924582.200) > > Band 1 Block=10065x32 Type=Byte, ColorInterp=Palette > > Image Structure Metadata: > > NBITS=1 > > Color Table (RGB with 2 entries) > > 0: 255,255,255,255 > > 1: 0,0,0,255 > > ----------------- > > > > What am I wrong ? > > > > Thx, > > > > -- > > ----------------- > > Andrea Peri > > . . . . . . . . . > > qwerty àèìòù > > ----------------- > > > > > > _______________________________________________ > > gdal-dev mailing list > > gdal-dev@lists.osgeo.org > > http://lists.osgeo.org/mailman/listinfo/gdal-dev > > > > > > -- > > ---------------------------------------+-------------------------------------- > I set the clouds in motion - turn up | Frank Warmerdam, > warmer...@pobox.com > light and sound - activate the windows | http://pobox.com/~warmerdam > and watch the world go round - Rush | Geospatial Software Developer > -- ----------------- Andrea Peri . . . . . . . . . qwerty àèìòù -----------------
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