Munsell to CMYK Conversion (Long Shot)

[z05DSL3A]

I have a Munsell reference that I need to convert to CMYK.

Does anyone know how to convert Munsell to CMYK (or an RGB colour space [D65 illuminant])? Or possibly convert it for me if you have the tools. I can't find anything on the net that will allow me to do one conversion for free.

The Reference is: 5.9 PB 3.4/15.1

Thank you.

[Duthomhas]

Must it be an "exact" conversion? (Munsell colors are inherently inexact uneven, alas.)

Oh, guess what I just found. :-)
http://www.cis.rit.edu/mcsl/online/munsell.php

[Duthomhas]

OK, here you go.

5.9PB 3.4/15.1 = CIE xyY 0.1694, 0.1218, 8.73

That's a linear conversion done by hand [extrapolating between the nearest points in "all.dat"]. (You may also want to check that.) You should be able to find an easy software conversion of CIE xyY to RGB. [edit] http://www.efg2.com/Lab/Graphics/Colors/Chromaticity.htm

Interesting color, BTW. What's it for?

[z05DSL3A]

Thank you, I'll check it out. When I was looking all roads seem to lead be to a different site and my boss wanted me to get on with coding.

It is quite a boring use, it is all to do with EU legislation. The EU flag has a Pantone reflex blue field (background) when it is used on paper work and website, however for use on car number plates it is specified with the Munsell reference (also should be retroreflective). We are looking into different ways on producing an acceptable flag with different print technologies.

http://en.wikipedia.org/wiki/Vehicle_registration_plates_of_the_European_Union

[Duthomhas]

Ah, interesting.

Yes, the people who do Munsell (and have the rights to produce fancy software for it) are X-Rite. http://www.xrite.com/top_munsell.aspx

I'm surprised that the EUC used the Munsell color (instead of a CIE specification), particularly on a shiny retroreflective surface, for which Munsell color specifications have no proper use... Go figure.

I hope you know that you are getting into a real can of worms when it comes to playing with exact colors. You've got to deal with chromacities and gamma and white spots and viewing conditions and stuff. Plus, the physical properties of video and print media are not 1:1.

You might just be better off getting a picture of a number plate that has the EU flag on it, and extrapolate colors from that. (Yes, you are dealing with more than one "color" when handling retroflectors.)

Aaaarrrrgghhh!

:-)

[z05DSL3A]

I can get hold of real number plates and use our spectrophotometer to get a good L*a*b reading, but I know that they are not the correct colour.

I hope you know that you are getting into a real can of worms when it comes to playing with exact colors.

:0) I know...thats what make it more interesting. I like producing colours that look the same in florescent light but have a noticeable difference in daylight. I'm trying to educate one of the managers who has printed a colour swatch on his home printer, as to the inaccuracy of this.

I did quite a bit on the nature of colour and light in a module on Computer Vision and Image Processing at University.

Everyones colour perception is also different... Aaaaaaarrrrgghhh indeed.

[Duthomhas]

My color perception is different between my left and right eyes. :-)

[chrisname]

What, so if you close one eye, everything changes colour?
That sounds like fun; I'm jealous...

[demosthenes2k8]

Haha, kinda happens to me as well. Everything is toned down out of my right eye...
I should probably learn about visual programming, I'm gonna have to use them this year for FIRST.

[Duthomhas]

Heh, LOL, it isn't quite that pronounced. Usually I don't notice it...

My color perception is actually pretty good. I scored a 4 here. http://www.spectralcolor.com/game/huetest_kiosk (I suppose I might have scored a bit lower if I hadn't rushed through the last bar...)

The Farnsworth and Munsell color tricks and tests don't usually trip me. I remember going to the Franklin Institute when young (a large science museum in Philadelphia) and they had a corridor with those silly squares of color, where the one on the left is bordered by one color and the one on the right is another. As I was young, you see, I didn't think to actually read what that was about, and I was fairly confused as to why they had two spots of the exact same color on the wall -- until my father pointed out its purpose. I thought it was pretty stupid since it was so obvious that the two colors were the same color...

[chrisname]

I got 7 on that test. It was really hard... :)

[Return 0]

Oh no! I must be going color blind, I scored a 24!! Granted I did this in about 5 minutes... I'll try again later.

[chrisname]

I would have done it faster than I did but I'm meant to be doing homework. I spent longer than five minutes though.

[Bazzy]

I scored 0!
Never thought of being so good in distinguishing colors

[z05DSL3A]

I did the test with my 'normal' monitor settings and got a score of 11.
I then re calibrated for with My 'photo editing' setting and did the test again a got the perfect score.

[chrisname]

Wow. You guys are good!

[demosthenes2k8]

I got a 39...

[Duthomhas]

Five minutes! Good grief! I could barely stand it anymore after two... (It's boring, you see.)

You must be going blind. (That or you need to calibrate your monitor... ;->)

[firedraco]

16. Didn't do anything about the monitor settings though. And I don't really want to take it again because:

It's boring

[Duthomhas]

Hmm, my wife just took it. She had a good number of colors out of place, and she got a four also!

I wonder how accurate the scoring criteria really is...