[argyllcms] Re: Ink Limit Override
- From: Graeme Gill <graeme@xxxxxxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Fri, 09 Aug 2013 16:43:35 +1000
Jason Campbell wrote:
> calculated Ink Limit (-v switch). However when I start getting to the 80%+
> tone value region, the profile starts sucking out on meŠ It pulls back on C
> and M and starts to push Y. In looking at where argyll wants to pin my
> total ink (when left alone; no -l switch) it puts me around 260%, and that
> is what I see in the curves coming from xicclu -- that it starts pulling
> back and at 100% C, M, and Y add up to just about that -- despite my attempt
> to push it.
Hi,
typically xicclu will indicate what's going on. The B2A table
is created by doing reverse lookups on the A2B table. If either there
are no entries in the A2B using more than 260% ink, or if the gamut
is not increased by using more than 260% ink, then it will never use it.
I would suspect the latter if your chart has 300% test patches.
Note also that the current code picks the darkest neutral as the
black point for the purposes of gamut mapping, so if your 300% patch is
not neutral even if it has a lower L*, then it probably won't be used
when a gamut mapped B2A table is created.
Without the profile or .ti3 data to play with, it's not possible
to say anything more specific.
Graeme Gill.
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