Etienne, you are really reason. I often forgot the great powerful of the tiff driver and so forgot also to read the tiff driver page.
Thx to remenber me this. Regards, 2011/9/3 Etienne Tourigny <[email protected]> > Andrea, > > please read the gtiff driver page at http://www.gdal.org/frmt_gtiff.html > > you need to add a few options, such as -co COMPRESS=CCITTFAX4 -co NBITS=1 > > Etienne > > On Fri, Sep 2, 2011 at 7:15 PM, Andrea Peri <[email protected]> wrote: > > > > 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 <[email protected]> > >> > >> 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 <[email protected]> > 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 > >> > [email protected] > >> > http://lists.osgeo.org/mailman/listinfo/gdal-dev > >> > > >> > >> > >> > >> -- > >> > ---------------------------------------+-------------------------------------- > >> I set the clouds in motion - turn up | Frank Warmerdam, > [email protected] > >> light and sound - activate the windows | http://pobox.com/~warmerdam > >> and watch the world go round - Rush | Geospatial Software Developer > > > > > > > > -- > > ----------------- > > Andrea Peri > > . . . . . . . . . > > qwerty àèìòù > > ----------------- > > > > > > _______________________________________________ > > gdal-dev mailing list > > [email protected] > > http://lists.osgeo.org/mailman/listinfo/gdal-dev > -- ----------------- Andrea Peri . . . . . . . . . qwerty àèìòù -----------------
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