How to apply Pantone skin tones

[Guest]

Hi,

I run across this project where the artist defines human skin color by using Pantone: http://io9.gizmodo.com/5924115/human...pantone-colors

Now, I wonder what the best technique is to apply Pantone skin color to a portrait I take either on film or digital (Non flagship Canons are said to have weak red channel and color filter array). Reason is I assume both of them might add their tints whereas I want a fixed skin color that makes confortable during printing process.

As far as I know the red channel has most of the skin color range. My idea is so select red channel, create a new layer above the background and reveal the selection, then I pick the Pantone color I prefer and brush over the skin and change opacity to fine tune. I have had mixed feelings with the outcome.

Any better ideas?

Thanks

[skoobey]

Re: How to apply Pantone skin tones

If in only were that easy.

Yes, you can see what the Pantone color is in numbers like RGB, but skin is not a single uniform color all over.

You've got your highlights that are reflecting the lightsource, you've got your midtones that re reflecting the lightsource, but not all of the reflection is aimed directly at the camera, and you've got your shadows where the light is either being reflected a lot less, not at all, or even is a double reflection(meaning it's reflecting an object next to it and it's color rather then the main light source- like the bright yellow jacket next to human skin).

Now all those have a bunch of variety within them.

So what I would suggest is evening out all distractions in terms of color and then applying an overall color adjustment with skin selected(I make masks manually, channel selection often grabs a lot more then desired, as things reflect color onto each other like hair onto skin and vice versa). Now you've got your basic skin color.

[redcrown]

Re: How to apply Pantone skin tones

I don't have any experience with Pantone, but lots of experience with skin tones. So I looked into Pantone.

What a mess! The Pantone site lets you convert Pantone to RGB and CMYK. But they don't tell you what colorspace their RGB numbers are in. Is it sRGB, Adobe98, ProPhoto? Trial and error seems to indicate sRGB, but not exactly. So who knows?

If you download any of the images from the site you linked, they are in Adobe98. Bad practice for web. People will see them differently depending on whether their browser is color managed or not.

If you convert one of those images to sRGB, translate the Pantone number shown to sRGB, and overlay a color patch with those values, the patch does not match any portion of the skin. Not even close! Example: Pantone 60-7 C is maybe sRGB 190-59-70. That's a mid to dark red. Does not match anything in the image.

So, putting Pantone aside, how to match any skin tone to a target using Photoshop tools?

The best method I've found is using a Gradient Map, set to Hue or Color blend mode. You can build a Gradient Map with as many stops as desired. So, for example, you can have one set of values for shadows, different values for midtones, and even different values for highlights. The Gradient Map gives smooth transitions between the different tones.

Where you get those values is the challenge. You can follow some formulas, such as the often quoted CMYK ratios. Or use LAB formulas. Or "steal" the values from images you like and think have good skin tones. Or use Pantone if you can make sense of it. But notice the Pantone values in the example shown are single "global" values. Whatever values you choose need to be balanced for shadows, midtones, and highlights.

If you use a Gradient Map, or any layer in Color mode, you are modifying one color (the underlying color) with a different color. That can be a problem depending on how far apart the colors are. So, sometimes it's better to add a "desatruation" layer under the Color mode layer to remove the underlying color.

[klev]

Re: How to apply Pantone skin tones

If you convert one of those images to sRGB, translate the Pantone number shown to sRGB, and overlay a color patch with those values, the patch does not match any portion of the skin. Not even close! Example: Pantone 60-7 C is maybe sRGB 190-59-70. That's a mid to dark red. Does not match anything in the image.

They use some variation of sRGB. sRGB isn't 100% consistent. You can find slight matrix variations depending on where you find it. You can also have slight variations with cmyk conversions, so consider these things to be approximative.

Now, I wonder what the best technique is to apply Pantone skin color to a portrait I take either on film or digital (Non flagship Canons are said to have weak red channel and color filter array). Reason is I assume both of them might add their tints whereas I want a fixed skin color that makes confortable during printing process.

You only think you want that. The results look bad because skin isn't one color. You're likely to see a significant deviation in color balance between highlight, midtone, and shadow regions. It picks up some influence from its environment, and the way you see it is impacted by its surroundings. Skin also looks weird if there is no variation in the color balance.

I use several types of adjustments. If I want a pretty strong correction in highlights or shadows in addition to midtone values, I'll use color balance or channel mixer and curves. If I mainly want to see an impact on the midtones, then I use curves and selective color (typically just red).

Issues of filtering and signal reconstruction are complicated. Don't speculate on them. Just shoot what you have and focus on that, because even the cheapest slrs produce reasonably good results today.

It's difficult to write a really good response to some of your questions, because they're seated in so much misunderstanding.

You've got your highlights that are reflecting the lightsource, you've got your midtones that re reflecting the lightsource, but not all of the reflection is aimed directly at the camera, and you've got your shadows where the light is either being reflected a lot less, not at all, or even is a double reflection(meaning it's reflecting an object next to it and it's color rather then the main light source- like the bright yellow jacket next to human skin).

Well brighter areas on a given object will converge toward the color of whatever they are reflecting. I don't think that considering the level of indirection (really light is reflected millions of times) makes it any more intuitive.

[skoobey]

Re: How to apply Pantone skin tones

It's very complex and at the same time simple because all know these things "by instinct". I was just trying to point out that you can't paint an image like you would your house.

[andrewrodney]

Re: How to apply Pantone skin tones

Pantone for skin? Why? Seems silly. Use Lab values, very straightforward:

Here's a video on correcting skin tones without having to resort to CMYK, using Lab instead:

Low Rez (YouTube)

http://www.youtube.com/watch?v=dWaFDKrNrwc

High Rez

http://digitaldog.net/files/SkinToneVideo.mov

[edgework]

Re: How to apply Pantone skin tones

Great tutorial. Changed my thinking.

[skoobey]

Re: How to apply Pantone skin tones

I use HSB. It's all the same thing.

[Tony W]

Re: How to apply Pantone skin tones

HSB is not the same thing at all.

The individual HSB values change depending the RGB colour space you are working in. Whereas lab is device independent and the L* a* b* values will remain the same whatever flavour of working space you use (and appearance should remain the same within the gamut limits of that space).

I think Andrews point is that you do not need to convert to Lab or CMYK and back but use the Lab (therefore constant values across working spaces) values in the Info palette readout.

[klev]

Re: How to apply Pantone skin tones

HSB is not the same thing at all.

The individual HSB values change depending the RGB colour space you are working in. Whereas lab is device independent and the L* a* b* values will remain the same whatever flavour of working space you use (and appearance should remain the same within the gamut limits of that space).

Are you saying that photoshop defines HSB coordinates with respect to a specific RGB color space? How did you arrive at that or find it? I would like to look it up myself.

For what it's worth, something like Adobe 1998 can still be regarded as device independent, as it isn't designed to model the behavior of a specific device. It's just more constrained than LAB and depicted with respect to wavelength rather than cone response. Recall that RGB represents an entire class of color spaces.

Oh and I understand why he likes having the black channel separate there. I just find this limiting for other reasons.

[andrewrodney]

Re: How to apply Pantone skin tones

I think Andrews point is that you do not need to convert to Lab or CMYK and back but use the Lab (therefore constant values across working spaces) values in the Info palette readout.

Exactly, work by the numbers in the current color working space. And while Lab is really easy, this can be done in RGB too with a bit less precision and the need to concentrate on three values, once you get the overall concept of the ratio. Necessary in Lightroom before thankfully we got Lab readouts in version 5:

http://digitaldog.net/files/LR_Skintone_Ratio.jpg

[skoobey]

Re: How to apply Pantone skin tones

With all due respect Andrew, there is no "one" skin tone, so while those values CAN make much sense, those are not the only relations between values that work for olive, pink, somalian, whatever specific type skin tones. There are image tints, color falloff, tonal variables... reflections... infinite number of options.

Getting to know which tone/color combinations look good is something that comes with developing your skills and it takes time. Going by numbers is a good idea, and I find it really easy if you go by the HSB, LAB, CMYK, RGB, and in that order. It's just more intuitive with HSB and LAB, and you can get those readouts no matter which profile you're actually working in.

[andrewrodney]

Re: How to apply Pantone skin tones

With all due respect Andrew, there is no "one" skin tone, so while those values CAN make much sense, those are not the only relations between values that work for olive, pink, somalian, whatever specific type skin tones.

It's not the value per se, it's the RATIO you need to pay attention to in both RGB and Lab! And you'd be well advised to have a really good, calibrated display and examine color in context. Something no profile or set of pixel values can provide!

In Lab, the aStar and bStar values are key. Both should be positive values. Both should be within 15 units of each other. If the B value is lower than A, skin starts to appear magenta or pink looking. When B is higher than A the skin appears more yellow. The closer to zero, the more pale.

[skoobey]

Re: How to apply Pantone skin tones

It's often the case, BUT NOT A RULE. And there so many images that disproof that theory. I am not saying you are wrong, I am saying you are right, but then there are also many other ways of being right. Skin can be cyan and look good, same goes for red, pink, yellow, magenta... there are many possibilities to split tone an image etc. It's all about fitting the overall palette.

That 75% sugar 10% spice 5% nice = good skin tone... well not necessarily.
Like saying hue should be between 23 and 28. Doesn't really mean much unless it works for the WB of the image, or even the creative direction of the image which could be completely unrelated to the original.

[skoobey]

Re: How to apply Pantone skin tones

HSB is not the same thing at all.

The individual HSB values change depending the RGB colour space you are working in. Whereas lab is device independent and the L* a* b* values will remain the same whatever flavour of working space you use (and appearance should remain the same within the gamut limits of that space).

I think Andrews point is that you do not need to convert to Lab or CMYK and back but use the Lab (therefore constant values across working spaces) values in the Info palette readout.

Because it's so hard to just convert the reference images and put them in the same profile...

Fact is HSB is easy to understand, next comes LAB, then CMYK and RGB is the least intuitive. HSB/LAB are the way humans think anyway, and CMYK and RGB are just ways for us to make prints/show things on the screen. If you can go by numbers in LAB or HSB, and you sure can, then why not.