What tool can I use to fade between two existing colors in an image?

[Alex31018593jp9m]

Sometimes after doing some clone stamping, I end up with some unwanted borders/edges between different colors. How can I fade the color from one to the other, so that the edge/border is no longer obvious?

[Kevin Stohlmeyer]

Hi @Alex31018593jp9m can you share a screenshot of your image for reference? There are many ways to blend between colors/edges using masks, gradients, etc.

[Alex31018593jp9m]

Sure! I'm wondering about this in general, but I'll put an example.

In the attached screenshot, you can see a column (appearing very grainy, as this is a closely cropped excerpt from a film photo scan), and on the dark/shaded side of the column, I did some clone stamping to remove a streak of color I wanted to get rid of. Since I was cloning bits of texture from below the part I removed, and the column gets darker at the top, there's now a clear border where I stopped clone stamping.

Is there any tool I could use that would let be fade between these two shades somewhat, to make that border subtler?

[AlanGilbertson]

There are a number of ways to do that, but I feel that you're fixing the wrong problem, because there are other ways to remove the unwanted streak of color (content aware fill, generative fill, frequency separation using the mixer brush, perhaps even the patch tool or healing brush), that would do a better job than the clone stamp.

That said, one fairly simple way to tackle what you have now would be to copy a section of the column immediately below the dark patch onto a new layer, make it a Smart Object and set the blend mode to Lighter Color. Apply enough Guassian Blur to get a nice blend, then mask off what you don't need. Finally, add back enough noise to match the grain.

Another might be to make the dark and light into your foreground and background colors, add a layer, make a selection around the area where you want to smooth out the color, fill with the gradient and experiment from there to get good-looking result. You'll then want to add noise, as before.

If you're up for some experimenting and you like to be hands on rather than leaving it all to an automated tool, definitely look into frequency separation retouching for this. There were three sessions at MAX 2020 covering the technique in depth. The link I gave is to the first one, from where you can find the rest.

[Alex31018593jp9m]

Thanks so much for the thorough reply!

I had a feeling I might've taken the wrong approach to start with. You're probably right that there's a better tool to get rid of the original issue (a big light leak on the film, I believe). The reason I've liked using the clone stamp for easier versions of this kind of thing in the past, is that I can maintain the original grain of the film somewhat (well, I'm altering it of course, but the source of the clone has the same kind of grain/texture). Would any of the approaches you recommended allow me to use the original grain rather than add noise after the fact to try to mimic that grain?

Regardless of your answer, I'm going to start by checking out that frequency separation tutorial and see about starting over with this.

Thanks again for the help!

[Trevor.Dennis]

I don't often use the clone tool nowadays.  Small areas are easier to fix with Patch, Healing Brush and Remove tools. Larger areas can get us into trouble if there is perspective involved, and ot precise location is required.

If I wanted to extend the height of the orange building...

Then the clone tool would only fit at the starting point.

If you copy part of the original, you can move it and Free Transform to get a perfect fit.

Yes, I know that the Clone Source panel has options that would fix size and location issues, but it would be trial and error and take way longer than copy and FT.

[AlanGilbertson]

Frequency separation is what you need, because it separates the high frequency data (texture, film grain) from low frequency (color, tone). It's very simple in principle: you blur one copy of the image just enough to remove the high frequency information, then subtract it from a normal copy. (There are some details, but you'll get those from the tutorials and demos.)

Now you have one layer with texture but no color, and one with color but no texture. Added together, they are the original imag. You can now clone texture from one part of the image to another without affecting color. You can fix shading and color problems without touching the texture.

It's a very versatile technique. Earth Oliver and Sef McCullough show the best way to use it, imo, in that set of Adobe MAX sessions, but you can find a slew of other tutorials online.

[Alex31018593jp9m]

Wow, that's incredible sounding. Definitely going to start by learning that tool. I'll look into the tutorials you mentioned. Thanks for explaining how that works.

[Kevin Stohlmeyer]

@Alex31018593jp9m the easiest thing to do in cases like that IMO is to do one pass with one of the healing tools (spot healing) across the edge - it will blend between the two pretty seamlessly.

[Alex31018593jp9m]

Thanks! I'm going to finally properly learn those healing tools now. That's something I need available for editing. Appreciate the help!