Many times, a picture that I was hoping to be perfect comes out a little too dark. Thankfully, GIMP, a free photo manipulation program, has all the tools I need to rescue my favorite photos on my Linux machine.
Fixing a Dark Photo
I end up with a lot of photos that are just a little bit underexposed. In fact, sometimes I prefer to take a photo in low light and enhance it in GIMP, because the light of the sun or the flash is just too harsh. Take this picture of my son Jonathan in a Blurryface Halloween costume that he made himself. It was taken in low light, a single LED bulb being the only lighting source.
I ran this through the Levels Filter in the Colors Menu twice, using a bright spot on the shoulder harness of his backpack as the white level, and a section of his clothing for the black level.
Then I selected his body, clicked Select – Invert, and then reduced the saturation of the background using Hue-Saturation from the Colors Menu. I had to do this twice to get the right effect. Then I selected his head, and applied a Brightness-Contrast filter, bringing up both the lightness and the contrast. I also slightly increased the saturation of the subject. Here is the finished photo.
Compare this to an overexposed photo taken with the flash that same day.
I think you’ll agree that the photo that started out too dark and was edited afterward to be brighter is far more nuanced and pleasant to look at.
Fixing a Photo that Is Both Too Dark and Too Light
One picture I wanted to save was this one, of my son Jamie, chilling with his homie Shakespeare at the Dallas Arboretum. Not only is the foreground far too dark, the background is also far too bright.
I want to mention that when a picture is dark or underexposed, it is almost always salvageable, because all the information you need to save the photo is there. However, when a picture is too overexposed, it is often impossible to salvage it, because the too much of the image information is lost.
In this image we have both overexposed and underexposed areas. So I dealt with different sections of the image separately. I selected the less overexposed portions of the background using the Free Select Tool from the GIMP toolbar, and then used the Levels Tool from the Colors Menu to adjust it. The Levels Tool allows you to select a white and black input level, rebalancing the output levels of the image.
For photographic problems like these, I find the Free Select Tool is very useful. Some people prefer the Fuzzy Select Tool, but I have had so many problems with it, I often find the Free Select Tool to be much easier.
Then I selected the flowers, bushes, and trees in the foreground with the Free Select Tool. I used the Curves Tool from the Colors Menu to rebalance them.
Then I selected the area at the bottom of the photograph, including the subject, to edit that area separately. I used Brightness-Contrast from the Colors Menu to increase the brightness and contrast of this dark section of the photo.
The result was that the photo was improved, but the background still looked a bit strange, and the grassy area was totally missing from the image.
So I decided to clone some grass in from another image, also taken at the Dallas Arboretum. I selected the areas I wanted to clone the grass into with the Free Select Tool. Then I simply opened the other image in another tab, used CTRL + Click to select a spot on the grass, and cloned it in. I darkened and increased the saturation of the grass using the Brightness-Contrast and Hue-Saturation tools from the Colors Menu. Then I clicked CTRL + Select None, and used the clone tool again to blur the sharp lines left by the Select Tool.
Then from the Filters Menu, I applied a Mean Curvature Blur with 5 iterations. I also lightened his face and darkened his arms to correct an imbalance I saw there. I used the Clone Tool and the Hue-Saturation Tool to fix some problems in the background. Here is the result.
I think the overall result is pretty satisfying. I especially like the way that my son’s legs are positioned similarly to Shakespeare’s. It’s one of my favorite parts of this composition.
Conclusion
Fixing dark photos can be a bit of work, but the result is often worth the effort. In most cases, you can probably fix the problem using the Brightness-Contrast, Curves, or Levels Tools. But there are plenty of other tools in GIMP that will help you to salvage your underexposed photos.
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