2002.03.05 02:20 "16 bit LAB in TIFF - documentation update", by Chris Cox

2002.03.05 13:25 "Re: 16 bit LAB in TIFF - documentation update", by Martí Maria

Hi Chris,

In first place I would like to thank both Adobe for this TN and you for posting it here. Joris and me were struggling against several of those mutually incompatible proprietary encoding, and for sure the Adobe note has been clarifier.

I have still a couple of questions, which I'm sending to you abusing of your kindness. I understand probably you didn't even wrote this, but as a Adobe representative you are my best choice to get these ones answered.

  1. A lot of experimentation did show me that Adobe is using D50 as white point. This clashes with the D65 required by old spec. Which white point is supposed to be used?
  2. About ICCencoding. Lately, ICC has released spec 4.0, with several major changes. One of them that PCS L is no longer encoded as 0...ff00 but 0..ffff I'm amazed by the side effects this would have in, for example, TIFF Lab. The note talks about ICCLab with encoding 0..65280 But in current ICC spec PCS is encoded as 0..65535.

Please take these comments just as what they are. Not complains but only additional clarifications. I'm very happy to have now the "canonical" guide to Lab TIFF

With Best Regards,

Martí Maria
The little cms project