Removing Glare with GIMP

In my Self Promotion of InkedWith post, I mentioned that I had some plans to bring in some new battles with technology. This article is a simple battle I found for removing glare with GIMP in images. I had taken some pictures to be used for printing as well as posting to social media. The problem is that they included some glare. An example of one of these images is below.

Image of hemp charcoal eucalyptus soap before removing glare with GIMP
Image of hemp charcoal eucalyptus soap with glare not removed

While this image isn’t painful on the eyes, I was interested in trying the technique that I learned.

The Technique for Removing Glare

I first need to give a little credit to where I found this technique. The answer for removing glare with GIMP was found in the gimpusers forum. The link here said that you could remove glare by performing the following steps:

  1. Add a transparent layer over the image layer.
  2. Use layer mode ‘Soft light’ for the new layer.
  3. Set foreground color to black.
  4. Use the Airbrush tool with the brush 2. Hardness 025 and a size of almost 20 to spray on the new layer over the glares.
  5. The glare might not go away completely or the spray dot become to dark. In the latter case decrease the opacity of the upper layer a bit to match the surrounding colors.

Item #5 is a suggestion for getting the color to blend a little better instead of having a dark shadow over top of your image. As an additional tip, I would also suggest tinkering with the “brush” size as well. I had originally tried using the 20 as suggested but it just seemed to draw really dark lines on my image. Instead, I had more luck with brush sizes that were in the 500 range! Your results may vary of course.

What are the Results?

After implementing the suggested technique and some additional tinkering with brush sizes, I had an image with reduced glare. Below is the resulting image with a little glare reduction.

Image of hemp charcoal eucalyptus soap after removing glare with GIMP.
Image of hemp charcoal eucalyptus soap with glare not removed

As you can see, I didn’t remove all of the glare and that was intentional. I found that removing all of the glare resulted in an image without any depth. This was one of my more simple examples (that I actually saved the before and after). I originally implemented this technique on a much more challenging image before dabbling on this one.

Bonus Tip

While I’m giving tips, why not also mention that you can do the inverse with this technique. I had successfully lightened an image using the “inverse” of this method! If you set the foreground color to white instead of black, you can work to lighten areas of the image that had unwanted shadows. This particular image warranted the shadows to provide some perspective. The other image (I forgot to save the before / after) was to be used for a poster so I didn’t want any perspective in the image itself.


I forgot how awesome GIMP is for image editing. I also didn’t realize that removing glare with GIMP would be so simple!