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TIFF and LibTiff Mail List Archive

Thread

2001.10.05 22:22 "16-bit ICC L*a*b* ?", by Dwight Kelly
2001.10.06 14:32 "Re: 16-bit ICC L*a*b* ?", by Martí Maria
2001.10.08 13:32 "Re: 16-bit ICC L*a*b* ?", by Bill Radcliffe
2001.10.09 00:12 "Re: 16-bit ICC L*a*b* ?", by Martí Maria
2001.10.25 21:53 "Re: 16-bit ICC L*a*b* ?", by Joris Van Damme
2001.10.26 13:28 "Re: 16-bit ICC L*a*b* ?", by Martí Maria
2001.10.26 12:46 "Re: 16-bit ICC L*a*b* ?", by Joris Van Damme
2001.10.26 19:32 "Re: 16-bit ICC L*a*b* ?", by Martí Maria
2001.10.26 14:26 "Re: 16-bit ICC L*a*b* ?", by Dwight Kelly
2001.10.26 20:54 "Re: 16-bit ICC L*a*b* ?", by Martí Maria
2001.10.26 15:45 "Re: 16-bit ICC L*a*b* ?", by Joris Van Damme
2001.10.26 14:35 "Re: 16-bit ICC L*a*b* ?", by Joris Van Damme
2001.10.26 18:28 "Re: 16-bit ICC L*a*b* ?", by Joris Van Damme

2001.10.26 20:54 "Re: 16-bit ICC L*a*b* ?", by Martí Maria

Hi,

There are two photometric tag values for Lab color in TIFF.

value 8 is defined as "1976 CIE L*a*b*"
value 9 is defined as "ICC L*a*b"

That is!. Seems Dwight Kelly discovered the difference. I'm sending to you a small TIFF16 I have. It is labeled as Photometric 8. I'm pretty shure your big image is labeled as Photo=9. So, using ICC encoding. That is, an offset of 128 applied to a, b. Photo 8 is using the signed word way. Or at least that is what seems.

Pfew!, if this is the case, seems I can avoid your 30Mb sample ;-)

Regards,
Marti.