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May 2006
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2006.05.10 19:13 "Re: Tiff throws error on tiffinfo but not with tiffdump", by Gerben Vos
Jeremy Nix wrote: > > I have a tiff image that has been giving me problems with JAI (Java > Advanced Imaging). > ... > Group3Options (292) LONG (4) 1<0> > Compression Scheme: None > ... > Any ideas on why these commands worked differently? tiffdump is a lower-level utility than tiffinfo, so it tends to give less error messages and warnings. > Is there something inherently wrong with the tiff image? There is nothing really wrong, although it is a bit strange that the image has a Group 3 options tag while it isn't compressed, which is what tiffinfo complains about. Also, while I calculated the correct strip byte count to check if it's really uncompressed (ceil(2544 / 8) * 3295), I noticed that the strips contain 14 bytes too many, which is a bit strange too. Probably has been rounded up to a multiple of 16. Neither of these strangenesses should be anything to worry about. Fill order 2 (lsb-to-msb) isn't very standard. JAI should still be able to read the image, but if it doesn't support this fill order, you'll get a vertically striped effect (the bits in every byte have been reversed). Or this field may be set to 2 while it really should be 1 and JAI is reversing the bits for you, which you don't want. That would be an error in the TIFF. Maybe the fill order and group 3 options have been wrongly copied over while uncompressing the image. I'm not sure if the values of the page number fields are correct; I've never used them, but the way I read the standard they should be <0 2> and <1 2>. Most software ignores this field. That's all I can make of this data. Hope it helps! Cheers, Gerben Vos.