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2007.01.31 18:50 "Re: 16bit grayscale with colormap", by Reinhard Mayr Aka Czerwinski
Hmmm ... I go the same message with ImageMagick's imdisplay.exe. Maybe the error message is just a bit too un-exact: the color map is there (according to the dump), maybe it's just about the unexpected length of 192kB instead of 256 byte? The values of the dump represent exactly what I have in the color map (repeated ASCII "0123456789ABCDEF"). Does GraphMagick do a length check for that tag? -------- Original-Nachricht -------- Datum: Wed, 31 Jan 2007 11:53:41 -0600 (CST) Von: Bob Friesenhahn <bfriesen@simple.dallas.tx.us> An: Reinhard Mayr aka Czerwinski <czerwinski1977@gmx.net> CC: tiff@lists.maptools.org Betreff: Re: [Tiff] 16bit grayscale with colormap > On Wed, 31 Jan 2007, Reinhard Mayr aka Czerwinski wrote: > > > Bob, > > > > thanks for that quick response! Attached there is the mentioned sample > file I created with a hex editor. (The colormap contains just crap data > but > should be enough for a proof of concept.) The opening behavior of some > programs was described in my initial post. > > > > How can you display the file? > > No, I can not. In fact libtiff's tiffinfo does not like the file > either (libtiff fails to locate the colormap) so it seems that the > file is not formulated correctly: > > % tiffinfo CytoScout16bitImageJ-0106_3-v5.tif > CytoScout16bitImageJ-0106_3-v5.tif: Error fetching data for field > "ColorMap". > MissingRequired: CytoScout16bitImageJ-0106_3-v5.tif: TIFF directory is > missing required "Colormap" field. > > % tiffdump CytoScout16bitImageJ-0106_3-v5.tif > CytoScout16bitImageJ-0106_3-v5.tif: > Magic: 0x4d4d <big-endian> Version: 0x2a > Directory 0: offset 8 (0x8) next 0 (0) > SubFileType (254) LONG (4) 1<0> > ImageWidth (256) SHORT (3) 1<200> > ImageLength (257) SHORT (3) 1<200> > BitsPerSample (258) SHORT (3) 1<16> > Photometric (262) SHORT (3) 1<3> > ImageDescription (270) ASCII (2) 34<ImageJ=1.37v\nmin=57.0\nma ...> > StripOffsets (273) LONG (4) 1<768> > SamplesPerPixel (277) SHORT (3) 1<1> > RowsPerStrip (278) SHORT (3) 1<200> > StripByteCounts (279) LONG (4) 1<80000> > Colormap (320) SHORT (3) 196608<12337 12851 13365 13879 14393 16706 > 17220 17734 12337 12851 13365 13879 14393 16706 17220 17734 12337 > 12851 13365 13879 14393 16706 17220 17734 ...> > > The error reported by libtiff when used by GraphicsMagick is that it > fails to retrieve the colormap: > > Error fetching data for field "ColorMap". > > Bob > ====================================== > Bob Friesenhahn > bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ > GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ -- Der GMX SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen! Ideal für Modem und ISDN: http://www.gmx.net/de/go/smartsurfer