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December 2001
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2001.12.18 00:52 "Re: Newbie need help! Please!", by Takao Matsuda
Hello Juergen. First of all, it would be easier to understand if you write figures in Hex format, I think. ie. 00 FF 2D EC ... At 12:47 +0100 01.12.17, Juergen May wrote: > Hi! > > I'm a newbie and have a problem understanding the TIFF data structure. > > I need to get the resolution of a bi-level TIFF image but can't seem to get > the value. I know the resolution is 300 so I'm expecting to find contiguous > bytes with the values 1 and 44 (decimal). > > Now, if I'm right, the value bytes in the tag 282 (x resolution) act as a > pointer. In my instance, the values are as follows - > > 1 26 - Tag 282 > 0 5 - Rational type > 0 0 0 1 - Count > 0 0 0 182 - ??? > > I don't understand what 182 means!? Is this an offset from the start of the > file? Yes. > If so, the value from 182 are - > > 0 45 198 192 > 0 0 39 16 > 0 45 198 192 > 0 0 39 16 They are 00 2D C6 C0 00 00 27 10 2DC6C0 (3000000) is a denominator and 2710 (10000) is a molecule 2DC6C0 (300000) / 2710 (10000) = 12C (300) And the second combination of 00 2D C6 C0 and 00 00 27 10 are for Y resolution, I guess. Does this help? Takao