Using Curves to match values from Color Sampler Tool

[southwestform]

I used the Color Sampler Tool to place a target on the skin tone I want to match to (sample #1) and I place a target on the skin tone I want to change(sample #2)

I create a Curves Adjustment Layer clipped to the layer I want to change the skin tone of

1. What gets entered into the Input and Output fields for the Curves to match the skin tones? The sample I want to use shows R=209/209 G=165/165 B141/141

Thanks in advance!

[davescm]

Hi

Use more than two points - preferably three or more on each taken from similar shadow mid and highlight areas of the skin

Then In curves switch in turn to Red - then Blue  then Green, each time adjusting the curve by dragging it , whilst watching the info panel, to match the pairs of points points as closely as possible. Don't be tempted to make the curves too jagged to get an exact match - it will look worse than just a close match with a smooth curve

Dave

[southwestform]

1. How do you determine where to drag on the curve? I’m currently dragging somewhere around the middle of it in each of the R,G,B channels.

2. To simplify this for now, I made two sample points, #1 is where the skin needs to change, #2 is the skin that I want to match to. I am now looking at the Info Panel and just dragging up on the middle of the curve until the values in the second column in the #1 area for the R,G,B values match the R,G,B values in the #2 area. Is this the correct way to do this??

Thanks!!!

[davescm]

Dragging the middle will work for one pair. More than one pair of points will help you with where to drag the curve to match the "shape"

Dave

[southwestform]

How do you decide where to place the point(s)? I just placed a single point in roughly the middle of the curve, which I think are the midtones.

Thanks for your help!

[davescm]

Pick a bit of a range and look for what you want to be similar tones.  Don't try and "mangle" the curves with multiple bends. Just try and do a single pull on each curve to get a best fit - which may not be exact on any point but will look natural.

Dave

[c.pfaffenbichler]

cmd-shift clicking with the TAT should create points in the channel-curves.

[Lhemz0527]

First ensure that your Color Sampler Tool is not set to Point Sample.

If you have a low resolution photo, use Sample Size: 3 X 3

If you have a high resolution photo, use Sample Size: 5 X 5 or more

When selecting samples, ensure that they are not too similar in value/brightness.

Selecting from shadow, midtone and highlight as davescm​ mentioned above.

Once you have selected samples in each images, you will have 6 colors.

If you are working in RGB you will have:

• Image to be adjusted: R1G1B1(highlight), R2G2B2(midtone), R3G3B3 (shadow)
• Image with target  color: R4G4B4(highlight), R5G5B5(midtone), R5G5B5 (shadow)

Now you are ready to match the color using Curves:

In the Curves settings, go the the Red Channel.

Cilck 3 random points. For each point set the input and output values:

• Point 1
  • Input: R1
  • Output: R4
• Point 2
  • Input: R2
  • Output: R5
• Point 3
  • Input: R3
  • Output: R6

Apply the same method in Green and Blue Channel.

After this, you should not be dragging the points around.

If you selected your highlights, shadow and midtones carefully, you curve will not be jagged.

[Don't forget to click my star ✪ if it's helpful. ]

[southwestform]

I ended up using the hand with the finger to click on the area of the image that I want to adjust on the curve and I dragged either up or down to adjust the R,G,B values of the layer that I want to adjust.

1. Is this a sufficient/accurate alternate way choosing anchors on the image I want to change?

2. While dragging at the selected point and watching the values in my Info Panel I see the values for my second column numbers changing for both the layer I am changing, and the layer I am trying to match to. Why are the values changing for the second column I’m trying to match my new layer to? The Curve is clipped to just the layer I am trying to adjust. Shouldn't the Curve not be affecting this area of the image?

Thanks everyone!

[edgrimley]

I'm not certain that this is what you are looking for, but...
Using the hand tool in Curves, hold shift+ctrl and click on the color you want to locate on the curve. (In the screenshot I clicked on the sky)  Each color channel will be marked (as shown in the red channel).With each channel active change the output value to the RGB value of the replacemnet color.

[davescm]

Hi

southwestform  wrote

I ended up using the hand with the finger to click on the area of the image that I want to adjust on the curve and I dragged either up or down to adjust the R,G,B values of the layer that I want to adjust.

1. Is this a sufficient/accurate alternate way choosing anchors on the image I want to change?

That should be fine

2. While dragging at the selected point and watching the values in my Info Panel I see the values for my second column numbers changing for both the layer I am changing, and the layer I am trying to match to. Why are the values changing for the second column I’m trying to match my new layer to? The Curve is clipped to just the layer I am trying to adjust. Shouldn't the Curve not be affecting this area of the image?

The curve adjustment should just apply changes in the area it is clipped to, and that should be reflected in the info panel - provided your other sample point is outside the clipped area

Can you show a screenshot - please include the options bar with the sample tool selected , the layers panel, the info panel and a view of the image (cover up any faces if that would be a problem)

Dave

[southwestform]

I tried with a new file and now it seems to be working as expected.

So far, I have only been working with 1 sample point for the clipped layer and 1 point for the layer that I am trying to match to.

1. For clarification, to make a more advanced change with the curve, do I place samples in a dark area, midtone area, and highlight area of both the clipped layer and the layer I want to match to and just match the values in the info panel for the clipped layer to the other layer by dragging in the R,G,B channels for each point? So a total of 3 points on the curve that will be adjusted?

2. If so, what if one of the layers does not have shadows, midtones or highlights while the other does? Do you just skip doing that adjustment?

Thanks so much!