How To Sharpen Image in GIMP

Making sure your images are sharp is a necessity. By applying sharpening effect, we can remove fuzziness from our images. In this tutorial, you will learn how to sharpen an image in GIMP using Filters>Enhance>Unsharp Mask command. If you want to enhances fine details, you can use high pass filter, instead.

For this tutorial, I will be using GIMP 2.10.18. If you don’t already have The GIMP, you can download it from https://www.gimp.org/downloads/. 

If you liked my tutorials, please subscribe to my YouTube channel - JTSGraph.

Steps to sharpen an image in GIMP:

1. Open image

Use File>Open (or Ctrl+O). 

In the “Open Image” dialog, navigate through your folders in the Places panel and the Name panel until your images' name appears in the Name panel. Click the image you want to open. Click Open. 

For this GIMP tutorial, I'll use this image, 1185279, downloaded from Pixabay.

2. Duplicate Layer

Preserve your original image by duplicating the image layer. Go to Layer>Duplicate Layer (or Shift+Ctrl+D). 

This creates a new perfect copy of the currently active layer just above. 

3. Zoom Image up to 100%

Use View> Zoom>1:1 (100%). This option maximizes the image.

4. Apply the Unsharp Mask filter on duplicate layer

Activate the duplicate layer by clicking on it.

Then use Filters>Enhance>Sharpen (Unsharp Mask). 

In the Unsharp Mask pop-up window, enter a value for the Radius, Amount and Threshold either through the up and down arrows or with the slider.

• Radius, adjusts how many pixels on either side of an edge you wish to process. 
• Amount, strength of sharpening.
• Threshold, the minimum difference in pixel values that indicates an edge where sharpen must be applied.

If you're not happy with the result, you can quickly undo a step at any time by going to Edit>Undo or else just pressing Ctrl+Z. 

Experiment with different values and discover values that works best for your image. Once you are satisfied with the result, click "OK" to apply them to the image.

And here is the image after applying unsharp mask filter:

5. Save document

Use File>Save or press Ctrl+S. 

In the “Save Image” dialog, type your document's name in the “Name” box and save it. 

It's better you save it using the extension “.xcf”. XCF is GIMP's native format, and is useful because it stores everything about your image and will allow you to later edit your image in GIMP, in case you notice a problem. 

Once you have finished, you will probably also want to export the image, using File>Export As, in a more widely used format, such as JPEG, PNG, TIFF, etc.

Choose JPEG or PNG then click Export.

More on GIMP Tutorials:

• Sharpen an Image in GIMP (High Pass Filter)
• How to remove Background in GIMP using Paths Tool
• How to Add graphic watermark to photo in GIMP
• Add Text Watermark to photo in GIMP