Color correcting skin tones and WB in Photoshop

[santoro80]

What are the best ways for color correcting skin tones and setting white balance in Photoshop. I don't mean by the eye.

[mistermonday]

Curves, levels, selective color, channel mixer, ...... and the list goes on. The most efficient method depends on what the source lookslike and the amount of correction required. It is helpful to establish some reference points using numerical values because even if you eyes are tricked and your display is out of calibration, the numbers never lie.
I use LAB color for many of my reference points. That does not mean you need to convert the image to LAB mode. Just set one of the alternate eyedropper views in the Navigation panel to LAB for viewing only.
Reagrds, Murray

[santoro80]

What are the numerical values?

[mistermonday]

There is no one set of numbers suitable for everyone. It partly depends on your working color space and to what type of printer your output is intended for. For example the darkest black that can be acceptably printed for you might be 10/10/10 (in RGB) for me it might be 15/15/15. Similarly for white it might be 245/245/245. You need to create your own reference points. One thing that may be helpful to you would be to download some color and B&W printer calibration / test images of which the are many around. Regards, Murray

[Boneappetit]

A nice and easy way to correct skin tones... http://www.smugmug.com/help/skin-tone

[ratpat13]

Unless your using a graycard or have something you know is suppose to be neutral in the image then regardless of the tool you use (curves, color balance, levels) the adjustment has to be by eye. As other have pointed out you can do it "By The Numbers" but it's no guarantee. It can be a really good method but it will often still require additional adjustment, which is often the case with any automated or formulaic method in Photoshop.

I've attached a jpg version of the "By The Numbers" approach for you.

So learn the "by the numbers" approach and then learn how to fine tune with cures or color balance. But nothing will replace knowing how to do it by hand with appropriate tools like curves, it's knowledge that applies to all areas of color correcting and editing images.

[John Wheeler]

Lots of good pointers on adjusting skin tone. Here is another link to a recent thread on the same topic. One of the included links shows how to adjust skin tone with a single curves adjustment layer within RGB mode. They use the "Targeted Adjustment Tool" (the finger) available within the Curves Adjustment Layer dialog for accurate adjustments. I have used that approach and have been quite pleased with the results. In all cases to do this by the numbers you need to know the targeted CMYK or RGB numbers referenced in previous posts.

http://www.retouchpro.com/forums/pho...ect-photo.html

[andrewrodney]

Originally Posted by Boneappetit

A nice and easy way to correct skin tones... http://www.smugmug.com/help/skin-tone

No where in the piece do they tell the reader what CMYK recipe is being used for the values which is pretty inexcusable considering every CMYK process is different (and the same process with differing UCR/GCR will greatly affect the values). Use Lab! Its totally non ambiguous in terms of the values, everywhere. You only need to really deal two values (aStar and bStar). This old “use CMYK values” is an old and not especially useful technique considering the CMYK color model and the fact that Lab is device independent.

Generally speaking, when a and bStar values are positive and close in value, you’re in good shape. Using the Roman 16 reference files, there are a number of differing kinds of skin tone provided. Values are aprox 15-25 overall values plus or minus only 4-6 values for both aStar and bStar in either channel. Just find good reference images (or images you have that you know output correctly) set the eyedropper sampling appropriately (not point) and get a feeling for where the aStar and bStar values fall.

That said, in an RGB working space, the values are pretty consistent too (but you have three values to watch, 2 values in a device independent color module is just easier).

In terms of RGB percentages in an Adobe raw processor like Lightroom, its easy because this color space doesn’t change (its LR’s internal processing space). Examples of ratio’s:http://digitaldog.net/files/LR_Skintone_Ratio.jpg

I’d rather do as much adjusting here (in the raw processor as possible), then if you need to tweak selectively in Photoshop, go by Lab values.

[andrewrodney]

Originally Posted by andrewrodney

No where in the piece do they tell the reader what CMYK recipe is being used for the values which is pretty inexcusable considering every CMYK process is different

Example:
http://digitaldog.net/files/CMYKSkin.jpg

[ray12]

Each person has their own preferred skin tone colors. Magazines prefer the yellow/orange/ playboy look and Asians have different NUMBERS than do African Americans. So you have to tell me what nationality you want numbers for, and then what is your preference (lighter skinned, darker skin look, slightly yellow, slightly red, tanned, baby skin color ranges, white glamour model skin, ruddy old man colors etc).

Your quest for the NUMBERS is OK and good...but skin is so subjective and tied into the eye of the beholder...that you could end up making big mistakes in retouching JUST to the numbers. What I m saying is often there is a balance of numbers, likes, preferences, whats appropriate, what will print well, what kind of look does the customer want, is the project meant to have white skin, some moody kind of skin look etc.

In the past, I have created a chart of 20 white models and I have done the homework of number mapping all of their skin tone numbers... and then placed that color swatch on the chart... with the numbers listed. So If I need numbers or want to match a color swatch...I have a reference card.

You can do the same yourself with the color sampler tool and about 30 minutes from images of models that you love their skin tones on, or that show the range of differences between nationalities, or of outlying skin colors that are accepted but not common for example. Spending time doing this study yourself will give you personal knowledge of skin colors and what the numbers are likely to be. Maybe you want to redden some existing skin, or yellow it up, or make it more tan...by doing the methodological study you will have something objective to go by.

I feel your pressure to get numbers...but once you get some numbers... you will then join the ranks with us that have numbers... and now know that they are NOT The Whole Story.

A scientist ( A numbers Geek ) usually ends up creating Laboratory Beauty by the numbers...BUT...the artists and photographers amongst us...we just shoot images ...and we end up liking the numbers "that look good to us"

It seems like many of us have a personal bias as to what flesh tones look attractive to us.

Cheers,

Ray12

[santoro80]

I will be more specific in my query. My father gave a photo whith a weird colors and told me to do somehing with it. My monitor is not calibrated (I know I should have calibrateds monitor, but I dont), so I cant rely on my eyes. I need numbers. LAB mode sound interesting. I dont have any reference. I dont know what is good reference for this.
Since I dont have the mentioned picture anymore, I tried to open a random portrait and I tried to deliberately shift the color. Than I checked the values of the original picture in LAB and tried to replicate it on the color shifted picture. The values of the original skin were L:71/a:16/b:13. When I adjusted the color shifted image to this values (with curves), the color were not the same... So maybe I'm doing something wrong or problably I dont know what I am doing at all

[John Wheeler]

Originally Posted by santoro80

My father gave a photo whith a weird colors and told me to do somehing with it. My monitor is not calibrated

This is control tower alpha-beta calling flight santoro80. Did we understand you right that there is no pilot on board and we need to attempt an instrument landing? First order of business: Are you estate documents in order?

Hi Santoro80
Sounds like you are flying blind a bit. From your description you may not have just a white balance issue that will yield to the normal techniques. Also, depending on how you color shifted your test image, these techniques may not work either. Here are some suggestions

Take this is a two step process.

1) Fix the gross color issues by using setting the Black, Gray, and White points in the image with those samplers in a Curves Adjustment Layer. This of course assumes that you know where in the image there are neutral color points for highlights, midtones, and shadows.

2) After step 1, then use one of the techniques already described. The one I have had good luck with is documented in this thread: http://www.retouchpro.com/forums/pho...ect-photo.html

That technique is done in RGB mode yet using the info panel with a sample point set to CMYK. Since the technique uses relative values of CMYK, it does pretty good without having to worry about absolute Lab color numbers.

Any technique will be a little rough flying since you do not have a color caliberated workflow yet you should be able to survive the landing. Good luck. Roger and out

[cspringer]

Download here....

http://www.mediafire.com/?bipw99097zd6ry2

CSpringer's Digital Grey Card Action

This is a short tutorial that explains some of the steps I take
with this action but keep in mind that like ALL Photoshop
edits, it DOES NOT work on every picture. If a photo does not
have a color cast it will introduce one. I find the biggest problem
people are having is thinking that there is a color issue when
in fact a little PWL, Levels or Curves to brighten the picture does the trick.

Assign a shortcut "F" key.

***IMPORTANT*** Run this action on an "uncropped original" image. It needs all of the color info from the original and introducing colors or a new cast will not work. Also, I find that I usually reduce the layer's opacity to 50% to blend with the original cast.

Open a file and run the action. Click the Color Bar at the top
of your picture with the Neutral (middle) Eyedropper.

You will see a "Contrast" layer that is disabled. The Levels on
this layer is in "NORMAL" blend mode vs. the "NO CONTRAST"
default layer which is in "COLOR" mode (does not affect
luminosity). If you like the outcome...great. However,
you might find it introduces the opposite color cast. Simply lower
the opacity until you are happy with the skin tones, leaves, etc.
and use the mask for blending.

The Color Tweak Group are also in "Color" blend mode
so it doesn't affect luminosity. I often use the Selective Color
Adjustment Layer for skin tones. The CYAN slider will add or reduce
RED and I usually add a bit of YELLOW.

The Hue/Saturation Adjustment Layer is used to adjust colors on
larger areas such as walls. A white/off white wall may still show
a color cast and by choosing EDITthe color...i.e, RED) and then
clicking with the eyedropper and adjusting the color bars at the
bottom, I can neutralize the RED or change colors. Use the mask
if needed.

If I don't like the outcome of the the "Contrast" or "No Contrast" layers
I disable both and use the COLOR TWEAK adjustment layers and
play with opacities and masks.


Here are examples supplied by fellow dpreviewers kennett, mrsbob, and Shaolin101

http://img.photobucket.com/albums/v2...algreycard.jpg

http://img.photobucket.com/albums/v2...rsDGCmsbob.jpg

http://img.photobucket.com/albums/v2...GCpigtails.jpg