Observer Metamerism: Wide Gamut Display Proof Views v Prints

[Doug Gray]

Interesting paper that explores the significance of individual color perception variations. It's becoming more of an issue with wide gamut monitors and causes people to perceive differences between soft proofs and prints even with careful color management and illuminant controls.

http://www.imaging.org/site/PDFS/Reporter/Articles/REP26_1_CIC18_SARKAR_PG307.pdf


The relevance of the observer variability issue is quite
dependent on the application context. In cross-media color
reproduction, the effect of observer variability has not been found
to be significant [3]. This is presumably true for most of the
industrial applications of the past several decades, be it printing,
photography, painting or textile. Thus, taking into account
individual observer variability in applied colorimetry did not
warrant a serious consideration in the past.

However, this limitation has become non-trivial with the
advent and wide-spread adoption of modern wide-gamut consumer
displays. Colors on two displays with very different spectral
characteristics are highly metameric in nature, often resulting in
colors that are a satisfactory match for one observer, and an
unacceptable match for another. This phenomenon, commonly
termed as observer metamerism, is particularly significant when at
least one of the two displays has narrow-band primaries

[Jack Hogan]

Interesting indeed Doug.  Looks like a new standard observer(s) is in the works.

[GWGill]

Looks like a new standard observer(s) is in the works.

They seem to have been proposed, but progress appears slow in formally approving or adopting such proposals. One barrier may be the view that the improvement offered is not worth the dislocation to existing luminosity and color standards. Another is validating such a fundamental standard before risking wide adoption.

[Czornyj]

Interesting paper that explores the significance of individual color perception variations. It's becoming more of an issue with wide gamut monitors and causes people to perceive differences between soft proofs and prints even with careful color management and illuminant controls.

Another one:
http://oicherman.com/Boris/Science/Boris_Oicherman_Phd_thesis.pdf

[Doug Gray]

Another one:
http://oicherman.com/Boris/Science/Boris_Oicherman_Phd_thesis.pdf

Much appreciated!  One thing I like about a PhD thesis v a specific topic paper is that they include a large amount of general background and analysis of evolving theories. I used to haunt the local university library and sometimes check out these works where interesting in the work I was doing at the time. Really found it helpful in expanding my own understanding. Even once hired a guy when I found his thesis particularly relevant. Turned out to be quite a valuable hire.

This one by Boris is simply excellent.  Thanks!

[Czornyj]

This one by Boris is simply excellent.

...and horryfing 

In the same cross-media colour matching conditions, we find significant systematic discrepancies between the predictions of the CIE Standard Colorimetric Observer and the mean matches made by the group of observers. We attribute these discrepancies to additivity failures caused by postreceptoral adaptation, leading to nonlinear change in sensitivity of S/(L+M) chromatic channel. An adaptation transform accounting for postreceptoral adaptation can compensate for the colorimetric discrepancies; a framework for such a transform is proposed.

[Tim Lookingbill]

...and horryfing 

Maybe the new definition for Standard Observer should be based on someone with a trained eye and a history of matching colors. Hopefully then we won't have to deal with and we can rule out this horrible adaptive effect.

I mean how long does one have to look at a color before adaptation changes perception?

[Doug Gray]

...and horryfing 

I particularly like this quote Boris includes from Billmeyer: 

Most men can seldom accept even the simplest and most obvious truth if it obliges
them to admit the falsity of conclusions which they have delighted in explaining to
colleagues, which they have proudly taught others, and which they have woven
thread by thread into the fabric of their lives

[GWGill]

...and horryfing 
Quote from: Boris Oicherman

    In the same cross-media colour matching conditions, we find significant systematic discrepancies between the predictions of the CIE Standard Colorimetric Observer and the mean matches made by the group of observers. We attribute these discrepancies to additivity failures caused by postreceptoral adaptation, leading to nonlinear change in sensitivity of S/(L+M) chromatic channel. An adaptation transform accounting for postreceptoral adaptation can compensate for the colorimetric discrepancies; a framework for such a transform is proposed.

Note that this refers to an apparent additive failure with regard to chromatic adaptation - it doesn't have anything to do with the standard observer curves or additivity failure at the cone level. He also made the claim that "It is impossible to design system which would create perfect colour reproduction for each individual observer." which I think is a little strong. It's certainly not currently practical to create such a system, but it's certainly possible if you are prepared to measure individual observer curves.

[Czornyj]

Note that this refers to an apparent additive failure with regard to chromatic adaptation - it doesn't have anything to do with the standard observer curves or additivity failure at the cone level.

That's exactly what I found particularly interesting. It seems that there's a problem with chromatic adaptation rather than with CMF.

[Tim Lookingbill]

So what is it with wide color gamut displays that cause color matching issues with prints? Are these displays a bit on the vibrant side even when calibrated and profiled?

Or is the white point/color temp characteristics (kinda' hard to see or describe between individual viewers) affecting chromatic adaptation between perceived print vs display matching?

The color of display white is very difficult to see until compared to another light source such as print viewing lights.

[Czornyj]

So what is it with wide color gamut displays that cause color matching issues with prints? Are these displays a bit on the vibrant side even when calibrated and profiled?

Or is the white point/color temp characteristics (kinda' hard to see or describe between individual viewers) affecting chromatic adaptation between perceived print vs display matching?

The color of display white is very difficult to see until compared to another light source such as print viewing lights.

It's narrow band spectrum, that (most probably) affects chromatic adaptation which leads to different perception of white. For example - wide gamut displays (OLED, RGB LED GBr LED, W-LED PFS) are often greenish or pinkish in comparison to standard gamut displays. And all displays look warmer than neutral paper under 5000K daylight (approx. 800K of difference according to UGRA study).

[Tim Lookingbill]

It's narrow band spectrum, that (most probably) affects chromatic adaptation which leads to different perception of white. For example - wide gamut displays (OLED, RGB LED GBr LED, W-LED PFS) are often greenish or pinkish in comparison to standard gamut displays. And all displays look warmer than neutral paper under 5000K daylight (approx. 800K of difference according to UGRA study).

I was afraid of that.

How off standard as measured can it get on these wide gamut displays if one were to eyeball correct the green/pink hue of white using internal RGB gains? I'm guessing it's never going to be a perfect match against any neutral white paper lit by 5000K daylight.

But how off from standard can neutral white get before it changes overall color perception?