QTR-Quadtone RIP

This is a fascinating discussion. Good question Brian. I feel like it would touch off an ICC standard if the grayscale world were larger.

My (experiential only) understanding is that we see colors and tonal values in relation to each other. Darks next to other darks appear lighter than darks next to lights. In some images pulling the darks down below linear works to build a perceptually “true” (for lack of a better word) print and in some images it doesn’t. Maybe this is why I think it un-stable . . . 

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Piezography is linear but with a big fat *. There are a lot of variables that Piezography depends on for linearity but the main one is gg2.2 data. I will share data when I get to it but anyone with a custom profile from us and our 256 patch target can validate that.

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Related to VMware and OS X, I’ll send details off-list tomorrow when I’m awake Roy. Thanks for chiming in. 

cheers,
Walker



> On Apr 19, 2016, at 8:17 PM, brian_downunda@... [QuadtoneRIP] <QuadtoneRIP@...m> wrote:
> 
> @Roy - Back in post #23, artodd138 asked "does anyone have a graph of L* values that would appear linear to a standard observer".  This question does not mention monitor-to-print matching, but all my attempts to guess an answer to this question have been dragged off into the weeds of matching.  I'm going to make one last attempt at this. 
> 
> Let's suppose we are in a room with no monitor, so no concept of matching.  We place a piece of paper in front of a viewer with a series of unlabelled, evenly-spaced grey patches, i.e. evenly spaced luminosity values, ranging from white to black, and ask them if they are evenly spaced.  It's my understanding that they would say no.  So the question is, what series of patches would they consider evenly spaced?  Again my understanding is that if the evenly spaced luminosity patches are converted to an ICC from QTR-Create-ICC and reprinted, then the observer would probably say yes.
> 
> I seem to recall a post somewhere in the past where you (Roy) said this, but can't locate it.  Is this an accurate memory, or a manufactured, false one?  If it's accurate, then there's the answer to artodd138's abstract, conceptual question.  If my recollection is false, then I'll pull my head in and go away, in which case artodd138 will have to find the answer elsewhere.
> 
> 
> ---In QuadtoneRIP@yahoogroups.com <mailto:QuadtoneRIP@yahoogroups.com>, <roy@...> wrote :
> 
> There's a lot of pretty loose talk about linearity.
> 
>