Hi [USER=69670]@IamSam[/USER]
I had never used the match color adjustment before, so I was mostly curious about why it did not work well. I heard mention of it a long time ago that it had issues, in particular with low-saturated target colors. I did not find anything online by doing a few experiments and deductions.
I personally do not like tools when I don't understand how they work (from a technical standpoint), and the Match Color tool was one of them. It tries to do so much, and when it works, it's great, but when it doesn't, it can be terrible without any real clues or advice on what to do differently. So, I observed a few things.
- It tries to determine "all" the source colors and then, with some unshared algorithm, adjust the hue and saturation (i.e., color) of the target image. So, it is definitely not set up to choose just one sample color to match and tries to use all the sample colors.
- I deduced that this does not work well in many situations, so I suspected they gave the option to use selections to choose one or a limited number of colors to use from the sample.
- Adding to the confusion, it can control if the same selection controls where you apply the colors. I did not explore that one and just turned it off. All the selection options won't show unless a selection is turned on in the Layer Stack (that is a bit confusing yet makes sense as a default)
- I did begin to understand why it has problems with low-saturated images for the target. In many images (especially ones with lossy compression), there are subtle differences in saturation and hue in the low-saturation areas. That is where it hides the compression. The Match Color tool, when used with such images, will significantly amplify those compression artifacts when trying to match multiple colors.
Using the image you used (I sourced from online), here is the original image:
[ATTACH=full]145428[/ATTACH]
Yet when you extract out the Hue component of this image at max saturation, it reveals the areas for artifacts:
[ATTACH=full]145429[/ATTACH]
You will notice that the patterns match a bit of what you were seeing. The Match Color tool sees these small variations and assigns colors with very poor results.
I chalk this up to a very, very early-made tool by Adobe, which was not up to the same quality as tools they build today (in my opinion)
I did not try to learn any more subtleties of the Match Color tool as I think I had enough to determine the root cause of the OP. I also learned that I personally need to use great caution with this tool, and I may never use it.
So that brings me to an approach I used for matching single colors.
First, when matching colors, one must use the color space associated with the numbers one is given. Hex numbers are typically only associated with sRGB. sRGB is often the assumed color space when given RGB, HSB, etc yet that is not a given.
Second, when given an RGB or HSB number to match a color, that set of numbers specifies a solid singular color. That is fine if you want one solid identical, Hue, Saturation, and Brightness. Yet, in other cases, that set of numbers is to match the Hue exactly and Saturation as best one can while having the originating image guide the luminosity. Otherwise, you end up with a flat result and no depth. Note that the Match Color tool tries to do just that. So, we need to be a bit careful about matching a specific RGB or HSB set of numbers as in these later cases; at best, this can be done only for one area of the image. That is not bad and, in fact, is a lot more natural for many images.
Note that in Photoshop Blend modes, the Hue and Saturation equate to Color and do not include the Luminosity component.
My approach separates the Hue and Saturation (Color) settings from the Luminosity. I use Photoshop's Color Blend modes and Luminosity Blend modes.
Starting from the image [USER=69670]@IamSam[/USER] used and I repeated above, I first added a solid color adjustment Layer clipped to the lower layer and masked to adjust the Color (Hue and Sat) for the original image. This solid color Layer is set to the Blend mode of "Color." With this blend, the Luminosity of the original image is used/preserved.
[ATTACH=full]145432[/ATTACH]
The next step is to adjust the Luminosity of the image while preserving the Hue and preserving Saturation as best as can be done while adjusting the Luminosity.
I added a masked Curves Adjustment Layer clipped again to the lower layer with the Blend set to Luminosity.
I placed a color sample tool set to HSB and noted that HSB numbers were used when the color picker was used (one could also have set the Color Sampler point to Lab mode and noted the Lab numbers when the Match color was set.
In this case, I simply brought down the white point until the Color Sampler Point met my needs. From there, I bent the curve to the tone that seemed desirable to me.
[ATTACH=full]145433[/ATTACH]
Just another approach to consider
John Wheeler
