How to Use the Heal Tool in GIMP

If you’ve taken more than a single photo in your life, you’ve probably noticed that they don’t all turn out perfectly. Sometimes there’s a piece of dust on the lens, an unfortunate skin problem, or just something bothering your photographer’s eye that needs to be removed during post-processing in GIMP.

This close up of a Red-tailed Hawk in flight is a great shot, but it has a few dust spots in the sky that really distract from the image, not to mention that single uncooperatively raised feather – but I don’t want to throw it away and try again (I will try again, but only because photographing them is so much fun).

The Heal tool is the perfect option for fixing small irregularities in large sections of similar colors, such as skin tones or the clouds behind the hawk in my sample image. With some careful practice, this tool can be used in more complex visual areas, but let’s start with the basics before we dive deeper into the workflow.

The Quick Guide to the Heal Tool in GIMP

The Heal tool is easy to use and works in a similar way to the Clone tool. It also shares a lot of the same settings as other brush-based tools that you’ve probably already used in GIMP.

  • Step 1: Activate the tool from the toolbox under Clone, or with the keyboard shortcut H
  • Step 2: Hold Ctrl and click once somewhere on your image set the healing source point
  • Step 3: Heal away any irregularities in your image

That’s the barebones of the Heal tool, but like many tools that are easy to learn, it can be very tough to master. Start slow, and always have your undo command at the ready!

If you want to experiment right away on your own image, I don’t blame you, but if you want to learn more about how to use the Heal tool options along with an important tip to make sure it doesn’t ruin your editing workflow, read on.

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A Closer Look at Healing in GIMP

For this closer look, I’ll break down the steps of the Heal tool process and show you the best practice methods for how to keep your source pixels safe. This will go above and beyond the steps outlined above in the Quick Guide, so don’t get confused when the steps don’t match.

Step 1: A Healing Layer

Create a new layer by pressing Ctrl + Shift + N (Use Command + Shift + N on Mac), and name it something clear like “Healing Layer” so that you can keep track of it later on. This layer will hold all your “healed” pixels over top of your original untouched image layer.

Make sure that the Fill with: option is set to Transparency, or this process won’t work properly!

Step 2: Activate the Heal Tool

Fortunately, this one is quite easy. You can switch to the Heal tool using the keyboard shortcut H, or find it in the toolbox stacked under the Clone tool. No tricks here!

You can also access the Heal tool by opening the Tools menu, selecting Paint Tools, and clicking Heal in the submenu, as you can see above.

Step 3: Select Your Source

This one is a bit more complex, and it can be hard to get right when you’re starting out. The Heal tool works by smoothing out highlight and shadow irregularities without adjusting the color (usually), so you want to set your source point over a smooth, unblemished area.

This will let you paint with the “smoothness” of your source area, removing any existing highlights or shadows that create the effect of texture in other areas of the image. You can get some unexpected results at first, but practice makes perfect.

Hold the Ctrl key (or Command on a Mac) and click to set the source point. You can always change this source point later if you don’t like the results, so feel free to experiment a little bit to find the spot that works best for your particular image.

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Step 4: Heal Options

At last, we get to the clever bit. Because we created a new pixel layer in Step One, we can do all our healing on a separate layer without changing the pixels underneath. But in order to make the Heal tool recognize multiple layers, we need to enable the Sample merged option in the Heal tool options.

This is also where you can apply the standard adjustments that are found in almost all brush-based tools in GIMP. Adjustments such as size, edge hardness, and force, control the intensity of the healing effect.

Step 5: Time To Heal

With everything properly prepared, it’s time to actually do some healing! The process is fairly simple once you’ve got your settings customized just the way you want.

Using keyboard shortcuts for zooming can make the process much simpler, and I’ve got a whole other guide about how to zoom in and zoom out in GIMP, but using your + and keys is enough for situations like this.

Avoid using huge long strokes at the beginning, and stick to single clicks and short strokes until you’re sure how the source point will affect the process. You’ll be amazed at just how easy it can be to completely change the look of your image!

Non-Destructive Healing

If you’ve read any of my other image editing guides, you’ve probably seen me going on and on about the importance of non-destructive editing. It doesn’t sound sexy, exactly, but it can save you a huge amount of time if you need to go back and change some parts of your edit in the future.

It’s actually just a simple idea: whenever you’re doing any kind of cloning or healing, do it on a blank new layer that sits above your main image. Check the option marked Sample merged and draw on the new layer, and the tool will sample all visible pixels while cloning/healing, yet leaving the original layer untouched underneath.

This is a big time-saver if you need to adjust your edit later on for any reason since your changes aren’t ‘baked’ into the original source image pixels – they’re just sitting overtop. If your heal edges were too large, you can trim them down a bit with a layer mask or the Eraser tool instead of redoing the whole edit or adjusting the layer opacity to modify the effect.

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For extra bonus points (and to stop yourself from going crazy later), make sure you name your layer something clear so that it won’t get lost in the stack when you’ve got 20 others in the same image and there’s only a tiny layer thumbnail showing in the Layers panel.

Ideally, GIMP would include options to do this for all kinds of edits: adjustment layers that apply filters using layer masks instead of baking your adjustments directly into your pixel layers, but maybe we’ll get that upgrade in the next version of GIMP – whenever that will be 😉

When Healing Won’t Work

In my sample photo of the Red-tailed Hawk, the Heal tool is a great option for removing the dust spots. However, it’s not nearly so helpful when I want to remove the single raised feather sticking out above the smooth wing edge, as you can see in the example below.

When you’re bumping up against hard edges in your image, it’s usually better to use the Clone tool rather than the Heal tool. The Clone tool copies pixels more directly than the Heal tool and will produce a better result with less messing around.

That’s just about everything you need to know about how to use the Heal tool in GIMP! But like many things, taking the time to practice and get comfortable with the tool and its results is the best way to become a true master of healing.

Sounds cool, right? It’s also way faster than medical school. Enjoy! =)

About Thomas Boldt