2005.01.13 13:14 "[Tiff] TIFF - Unknown field with tag 34665", by Claude Houle

2005.01.13 13:55 "Re: [Tiff] TIFF - Unknown field with tag 34665", by Joris Van Damme

Folks,

Again, the default mailing list reply address is mocking things up. I am getting very tired of this.

Claude, please note that the default reply address is the sender, not the list. Thus, if you just hit reply, you're no longer posting on-list. Instead, hitting reply-all, in most mailing list clients, would do nicely. Alternatively, manually make sure tiff@remotesensing.org is in the TO or CC list.

Claude wrote to me privatly:
> Take a quick look at the Screenshot of IMDisplay versus the screenshot of
> GIMP, and you will see the difference. It is the same picture, but rendered
> differently somehow. The screenshot from GIMP is right, as is the screenshot
> from MS Photo Editor. But IMDisplay ( Image Magick 6.1.8-3 ) doesn't handle
> it properly ( They use libTIFF 3.5.1 if I remember well ).

Here's a tag dump of the file you've sent me:

SubFileType (1 Long): Zero
ImageWidth (1 Short): 191
ImageLength (1 Short): 224
BitsPerSample (4 Short): 8, 8, 8, 8
Compression (1 Short): Uncompressed
Photometric (1 Short): Seperated
StripOffsets (1 Long): 9376
SamplesPerPixel (1 Short): 4
RowsPerStrip (1 Short): 224
StripByteCounts (1 Long): 171136
XResolution (1 Rational): 300
YResolution (1 Rational): 300
PlanarConfig (1 Short): Contig
ResolutionUnit (1 Short): Inch
Software (20 ASCII): Adobe Photoshop 7.0
DateTime (20 ASCII): 2005:01:12 13:37:30
700 (4649 Byte): 60, 63, 120, 112, 97, 99, 107, 101, 116, 32,...
Photoshop (4420 Byte): 56, 66, 73, 77, 4, 37, 0, 0, 0, 0, 0, 16, 0,...
34665 (1 Long): 180512

See, it's a CMYK file. My guess is that some of your software can't handle CMYK. Anyway, I could not comment on that, it's an application issue, not a LibTiff issue, I think.

What could also be related, judging from the screenshots, is that Photoshop writes CMYK as 255 is no ink, and some others write CMYK as 255 is full ink. Or so I seem to remember, but I could be mistaking. If this is your problem, I don't think there's any good solution.

Perhaps you can avoid using CMYK alltogether?

Joris Van Damme
info@awaresystems.be
http://www.awaresystems.be/
Download your free TIFF tag viewer for windows here:
http://www.awaresystems.be/imaging/tiff/astifftagviewer.html