Now that everyone carries their camera with them everywhere, we can all make a claim to the title of “photographer.” And as image enthusiasts, blurry photos are annoying. They’re also extremely common, considering how frequently folks try to talk pictures in environments that don’t help your camera’s autofocus. Back lit environments, dark interior rooms, spotlit stages: none of these highly common photo-taking environments does any favors for the sharpness of your image. If you want to fix blurry photos on macOS, you can use either GIMP or Photoshop to improve the images sharpness.
Of course, we don’t have superpowers. You can’t magically turn an illegible photo into a flawless shot. We’re talking about a matter of degrees here. “Slightly less blurry” is the goal, not “magically tack sharp.”
What counts as “Blurry”
The word “blurry” encompasses a multitude of photographic issues. It typically means that the subject of the photo doesn’t appear sharp in the image. But there are many types of blur that can cause that problem. Before we can fix blurry photos, we have to understand what kind of blur is fixable and what kind of blur can’t be helped. There are two primary categories that the casual photographer needs to know about:
Motion blur results from the subject or the camera moving during the exposure.
This causes a characteristic streaking, which we sometimes think of as motion lines. This can happen even outside in bright light: in the above image, the dog moved too fast for the camera’s exposure settings, causing the blur. Notice that the other parts of the image, like the fence, are much sharper than the in-motion dog.
Focus blur comes from inaccurate focus. The camera might focus on the wrong part of the subject, or focus on nothing at all. Focus blur distinct from motion blur, and it’s what we will discuss fixing in this tutorial.
The back of the center coin is in focus, rather than the front. Notice the soft blur and gradual increase in blurriness characteristic of focus blur. While this type of blur can easily be used as an artistic tool, undesired blur is no one’s friend.
While we will focus on improving focus blur in this tutorial, motion blur can also be fixed to a limited extent. It requires different techniques and more advanced tools to get the best results.
Using unsharp mask to fix blurry photos
The classic way to sharpen photos is with a filter called “Unsharp Mask.” The history of the counter-intuitive name is interesting, but rest assured: it does sharpen images.
1. Open your image in GIMP or Photoshop. We will use GIMP for this example.
2. Select Unsharp Mask from the Filters menu. In GIMP 2.10 this is under Filters > Enhance > Sharpen (Unsharp Mask). In Photoshop you’ll find it in Filters > Sharpen > Unsharp Mask.
3. This will pop up a pane with some default settings. You can adjust these settings to better sharpen your image.
- Amount controls the strength of the mask. The higher the amount, the more edge contrast will be added to the image. It’s important to set this value properly. Too low and you’ll see no effect; too high, and you’ll see hideous effects.
- Radius controls what counts as an “edge” for sharpening purposes. Small radius values will sharpen fine detail, while high radius values will apply to larger edges. Radius is easy to set too high, so keep a steady hand.
- Threshold defines how many luminosity levels must change from one pixel to the next to define an edge. The higher the value, the less it counts as an edge. Smaller values will sharpen more edges, while higher values do the opposite.
Because each image is different, the optimal settings for each image will also be different. There is no “best” setting. You’ll gain experience through practice. Applying too much sharpening will lead to an unappealing high-contrast look that you’ll probably want to avoid.
4. Apply a mix of settings that you feel best sharpen the image. This is an art and not a science, so experiment.
While experimenting, you may want to see a comparison of your sharpened and unsharpened images. By ticking the Preview box on and off, you can toggle between the two images. You can also click Split View to see a side-by-side comparison. The split view tool is only available in GIMP.
Fix blurry photos with the high pass filter
Another method of sharpening is the high pass filter, which applies a different method of detecting edges.
1. First, duplicate your layer by right-clicking the layer and choosing Duplicate Layer from the context menu.
2. With your new layer selected, choose Filter > Enhance > High Pass in GIMP or Filter > Other > High Pass in Photoshop.
3. Adjust the settings until you can see the edges you want to sharpen, then click “OK” to apply.
Finding the right settings here is not intuitive, thanks to the image’s strange appearance. It will take some practice with this method of sharpening to know when you’ve nailed the settings. For now, just try to reveal the edges that you most want sharpened.
4. Change the blending mode for the layer to “Overlay” from the dropdown menu.
For more detailed control, you can adjust the opacity of the high pass layer after changing the blending mode.
Don’t go to far!
Newbies frequently oversharpen images. Use the image above as a guide. The image should be less blurry, but not distressingly high contrast or haloed. Try for the middle eye and avoid the bottom.
Fixing blur in photos is an art. It requires a careful and patient hand. Despite the incredible power of today’s computers, not all blur can be fixed. Extreme blur will remain unfixable, likely forever. When there isn’t enough data to create a sharp image, the computer can’t just imagine one. But light blurring can be recovered in many cases.
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