I used to do old fashioned darkroom photography and dodging and burning were often necessary to print something I'd shot. At least for me!

Now using Gimp (in Linux) I am trying to get good images of the oil paintings I've done over the last 35 years. Many of those are gone, and all I have are the slides and photos of them, now. I'm able to scan positives and negatives, and prints, of course.

In Gimp, I find most of the color and brightness/contrast adjustment tools useful, and also the transform>perspective tool to straighten out the images of paintings and crop them.

BUT, my present problem is how to dodge or burn certain areas of an image, rather than adjust the whole thing. This problem often comes up because the original lighting on the paintings may have been uneven when photographed, or the may be reflective glare off the paint itself.

Attached is an image I've currently been working on. The left side of the photo of the painting is washed out, although there's enough density in the original scan of a darker slide to get some detail there. I don't know how to burn that in compared to the rest of the image using Gimp.

Help in understanding how I can do that would be greatly appreciated. I have looked for answers here, and think I saw some mention of curves and a black and white layer, but I'm not actually familiar with how you would use these to affect only the over-lit portion of the image.

Thanks so much, in advance!

ps I know the image is presently dark, but I wanted to correct the lighting imbalance first before doing any further global adjustment, etc.

Have you tried setting the layer mode to Burn or Dodge. I set it as burn and painted black and it seemed to have make it a little darker like burning effect

Okay thanks TinT, I'll try that.

(Had to look up what a Burn layer was. I did find a YouTube video that demonstrated something similar, I think. I'll try that method, and report back with how well it went....)

What format are you saving your scans in? Best format for that is tiff, scan to the highest dpi and color depth that your scanner can handle, and the highest dpi that is practical memory wise for your system.

You may want to look into ART, Darktable, and Rawtherapy for your image processing as well.

What's ART, please?

It is a fork of Rawtherapee for editing RAW photo images

https://bitbucket.org/agriggio/art/wiki/Home

Thank you, Rich.

Thanks @Wallace, I've been trying the Burn tool this morning with varrying results using about 20% exposure and .025 brush. Main problem is that the burn hue is a little cooler (bluer) than the rest of the painting. Possibly because the highlighted area was a result of sunlight reflecting off of the painting there.

Thanks @AdmFubar, I will try that for a final attempt. Right now I'm testing things out on just the png to see how these tools work.

@TinT the video I've been trying to follow is on Youtube -- I can't give a link yet (as a newbie to the forum, because it thinks that's spam) but the youtube view hash is NsbCP0XWfEM . I can't get that to work on the png image I'm experimenting with. It just won't burn when I use the paintbrush. I'm using Gimp 2.10.18, which seems pretty close to the version he is using in the video.

@AdmFubar, I've also downloaded ART, DarkTable and RawTherapee, just to have a look. Looks like some steep learning curves for me just in terminology alone. I'm going to try first to do the best I can in GIMP, but am open to anything that I can get the job done with, re. Burning. Thanks for the recommendations.

Hello. Welcome.

A variation for dodge and burn work on specific areas of an image. Just something you might want to try.

Open your image.

Create a new layer the same size as the original image above the original image.

Fill the new layer with middle gray RGB 128 128 128 by any means you want.

Set the gray layer to Overlay Mode. In the Layers Tab both layers need to be visible. Make sure the gray layer is the active layer. Although it is invisible in the work area it is the layer you actually paint on.

Just to know where you're starting from, use a solid black paintbrush at 100% opacity and hardness on the targeted [eye-selected] area.

To darken an area paint it with black as the foreground color.

To lighten an area paint it with white as the foreground color.

With the target area sufficiently covered, adjust, at your liberty, the gray layer opacity to mix to taste.



You can vary any of the options. You can make a regular hard-selected area to work on if the image and your hand-selection skills permit.

The first variation below shows the left-side black-painted overlay effect, which I believe is what you were looking for, balancing left- and right-side lighting.

The second variation takes the first variation, adds several lightened targets on other parts of the image, and adds an overall White Balance effect at the end. (Perhaps the sun was coming through two opposing windows. Strange day perhaps.)


I hope you will pardon the liberties I have taken with your art.

As a perpetual newbie myself I would like to say that in GIMP there are almost always multiple ways to end up at or near the same place. It may not take long to realize that anywhere you first "end up" may almost immediately suggest somewhere else to go.

I see Wallace has already answered as I was going to. Dont forget to check the tool options and click on the range you want to change. This being the 'highlight' areas with the burn tool.
As always there are different ways to get the same result in gimp and Neurolurker has shown 1.
Once you get it all to the same colour you can then make it lighter by using methods you have already found.

Thank you @neurolurker and @sallyanne!

neurolurker, your first variation is really good, and better than what I was achieving with the burn tool. That might have been because the burn tool was hard for me to use evenly by hand. Separations and overlapped tracks resulted.

Also I wasn't sure if you could also vary the hue to something other than black. I really needed to warm up the black a little towards the orange side to counteract the blue hue of the overlit area. I believe my photo was shot with incandescent light overhead, but the overexposed area was probably due to a reflection from a window. Therefore too blue even if darkened.

The film was probably indoor slide type as a guess (slide is 30 years old). Colors throughout most of the pic are good/true except for that one overlit area.

I'm guessing your masking method can accept something other than straight black as the foreground masking color, when burning.

Okay, I've learned a lot here! Definitely you can change the color of the brush for the layer from black.
I think this is the best I can do with what I have for a slide and my skills at this point.

I am so very glad you found the digital light-mixing suggestion useful. And very happy you carried it further on your own. Perhaps GIMP has been waiting for you to say hello.

BUT: I copped the paint-on-overlay idea from a small part of an old script by a user named Lowry. Some Foundry scripts no longer run on newer versions of GIMP but you can search for his name in the box above for the original script and variations.