[argyllcms] Re: Black turning down problem - help!
- From: Elena [service address] <1007140@xxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Mon, 10 Jan 2011 17:46:35 +0100
Hello Graeme
On 10-Jan-2011, Graeme Gill wrote:
> Elena [service address] wrote:
>> I'm improving my results but... at what a time cost!!!
>
> Once you have a feel for things, it shouldn't take so long.
>
> For some media (usually the good media), it's often less critical too.
>
> The lack of easy control over the black curve is where things have landed.
> I'm conscious that its ease of use could be improved. I don't know if or
> when that may be possible.
See my other mail also. And please forgive me if I sound repetitive or
just chaotic =)
Looking things from the point of view of a non-experienced or little-experienced
user (experienced here is relative to argyll skill, not to CM in general!) - one
would expect a correct result already with some default parameter - and correct
here doesn't mean perfect, just overall correct and without major visual issues.
So, a very default scenario as you suggest, i.e making a target for example
with targen -f1000 and a profile with colprof -qm -k[x,z,h,r] -l[how much I
know my
paper accepts] SHOULD already drive to a first correct (=useable) result.
That said in general.
Now, when an user makes a choice on the K generation, usually this choice is
driven by factors such 1) I prefer a moderate or almost null K in the light
tones
because I don't want to see rosettes (or pepper) too early 2) I use a fine
screen so I want my neutrals being composed as most as possible by black, so I
minimize metamerism issues 3) I prefer a purer K at deep blacks rather than
a heavily composed one because my paper behaves better this way - EVEN IF
THAT WON'T PERHAPS RESULT IN MAXIMUM (measured) DEPTH, an aware choice, etc,
etc, etc.
One turns out instead to have to play heavily with xicclu just for eliminating
visual bumps or irregularities.
Now, don't just consider my experience with plain paper any longer. Those
or even worse things do happen, with many different substrates. Think of people
who need to profile solvent printers, or to print on aluminium!
As I already said in the other msg, I think colprof should be wise enough to
detect major visual irregularities, and in the case, suggest a number of
patches to add to a new target trying to correct the problem. This could be
a file automatically generated, to be integrated in the previous ti1 target.
I'm telling that, of course, without having never written profiling code,
of course, so be tolerant... :-)
The other major modification I would do, as I already told, is changing the
way -k and -K work to make them more intuitive (and perhaps better documented,
of course) - but again please take that carefully since I know there may be
side effects as well.
What I suggest, is that -k parameters should be taken literally, within the
total responsability of the user, even if that won't perhaps lead to 100%
accurate results (note that one thing is accuracy, while smoothness and
continuity is another thing).
-K, instead, should treat the parameters as a guide line, giving priority
to accuracy and measured dark tones.
I know I put it in a raw way, I can't explain better. Perhaps those are just
idiot thoughts.
Bye
/&
Other related posts:
