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May 1997
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1997.05.20 18:59 "Re: unknown field with tag 34377 (0x8649)", by Helge Blischke
Christoph Kukulies wrote: > > I got a file coming from some Apple Mac scanner program > and when I want to look at it using xv 3.10a I'm getting > > unknown field with tag 34377 (0x8649) > and > unknown photometric: 5 > > tifftopnm gives the same error. > > Are there any other tools around I could try to get around this problem? > > This is what tiffdump says: > plan.tif: > Magic: 0x4949 <little-endian> Version: 0x2a > ... [rest of the dump cut out]... > -- > Chris Christoph P. U. Kukulies kuku@gil.physik.rwth-aachen.de The tag 34377 is an Adobe reserved proprietary tag used by Adobe's Photoshop program to store information internal to the program (like information on paths and layers etc.); libtiff and many other programs give just a warning and ignore this tag and the associated data. Photometric 5 means CMYK (see section 16 of the TIFF6 spec), which cannot be handled by xv (as far as I know). Try to convert the image by photoshop (on Mac, PC or UNIX (e.g.Solaris). If you don't have access to any photoshop or equivalent program, you could hack a little libtiff based program to do the conversion. the simplest method is: R = 255 - C; G = 255 - M; B = 255 - Y; ignore K. Of course, the resulting RGB colors might not be axact; there are a couple of different algorithms used for this conversion in prepress systems; and I do not know how photoshop does this. Hope this helps, Helge -- H.Blischke@srz-berlin.de H.Blischke@srz-berlin.com H.Blischke@acm.org