2006.09.29 08:30 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Jean-Yves Le Ridant
What you may be thinking of is that Yves double-checked the ITULAB-TIFF-in-discuise with Photometric CIE Lab, by taking it into Photoshop and next correcting Photoshop's wrong take on this caused by the wrong Photometric, with various dials and bells, such that the image would start making sense if it was ITULAB despite of its Photometric. And it did start making sense.
I apologize for my previous post which is confusing. This file fax000..., with a white falling to 128,96 perfectly match what I read from the spec for both a and b layers.
Applying the transform with an imaging program is straightforward for a, but for b, one need dials and bells with both input and output levels to produce the exact transform, so what I uploaded ( qView.tif ) is very approx.