01 of 06
How to Use GIMP to Make a Portrait Digital Stamp
In this tutorial, you will learn how you can produce a digital stamp portrait using GIMP (we also have instructions for making a digital stamp from a photo using Photoshop Elements). You'll see how a photo of someone's face can quickly be turned into a distinctive black and white graphics. The technique is pretty simple, though results may vary depending on the original photo, so you may find this works better with some images than others.
For those unfamiliar with GIMP, it's a free open source image editor that is often considered as a free alternative to Adobe Photoshop. Speaking of Photoshop, there's also a tutorial that shows how you can use that to achieve the same effect and the technique is the same for Photoshop Elements too. You can download a free copy of GIMP if you want to follow along and don't have GIMP installed on your computer.Continue to 2 of 6 below.
02 of 06
Open Your Photo in GIMP
There are a couple of ways to open a photo in GIMP. The quickest is to drag the photo from Windows Explorer or Finder on Mac and drop it on the open GIMP window.
The alternative is to click the File menu item and then click Open from the drop-down menu. From there you will need to navigate to the folder where your photo is located and double-clicking the photo file will open it.
With your photo open, you can now move onto the next step and open the Threshold tool.Continue to 3 of 6 below.
03 of 06
Open the Threshold Tool in GIMP
You only need to use one tool to achieve this effect, and this is the Threshold tool. To open it, go to the Colors menu item and select Threshold from the drop-down menu that appears.
You'll notice that a new dialog window opens named Apply Threshold and also that your photo has turned to black and white.
In the Apply Threshold window, you can see a histogram that represents the tonal values of the photo with two slider controls directly beneath it. You don't need to understand how the histogram works to use the Threshold tool—you can quite happily experiment using the slider controls.Continue to 4 of 6 below.
04 of 06
How the Threshold Tool Works in GIMP
The Threshold tool analyzes every pixel in a photo and converts it to either pure black or pure white.
Imagine a scale of light and dark that stretches from 0-100, with zero representing pure black and 100 pure white, by default, the Threshold tool converts all pixels with a value of less than 50 to black. All of the remaining pixels are converted to white.Continue to 5 of 6 below.
05 of 06
Adjusting the Threshold Tool in GIMP
You only need to work with one of the Threshold tool's controls to create the rubber stamp-like effect that we're after, and that is the black triangle shaped slider control below the histogram.
When you first open the tool, the black slider is placed at the middle point. If you click and drag the slider to the left, you'll see that the photo becomes whiter overall, while sliding to the right makes the image darker.
When you move the slider, you are effectively changing the point at which pixels are converted to black or white. If you slide to the right, pixels that were previously to the right of the slider and were white are now to the left and are converted to black.
This simple adjustment allows you to change the effect. If you look at the image, you should see how the slider moved to the right, and this helped to show more facial features. The background also got darker, but you could always try using the eraser tool to remove the background. Bear in mind that with your photo, you may have to drag the slider control to the left to improve your image.Continue to 6 of 6 below.
06 of 06
How to Save Your Image in GIMP
To save your image, go to File and select Export As from the menu. In the dialog that opens, click Select File Type to show the list of file types and select either PNG image or JPEG image and click the Export button. On the next window, use the default settings unless you understand how to tweak the settings.
Now you can use your image as a digital stamp or even use it to create an actual rubber stamp.