GIMP has a great set of selection and transformation tools for editing your images – but the user interface sometimes makes it a bit difficult to use them the way you want. You probably know how to make a selection in GIMP, but what if you want to rotate that selection?
Before we get started, it’s important to point out that there are actually two different ideas here: you can select a part of your image and then rotate that selected part of the image, or you can actually rotate the selection area itself and not the image contents.
They both have their uses, so I’ll explain how both options work in this quick tutorial. I’m going to assume that you’ve already made your selection, so we’ll skip right ahead to the rotation part of the process.
Rotate Your Image Selection in GIMP
If you want to rotate the actual image data that you have selected, you’ll need to use either the Rotate tool or the Unified Transform tool. The Unified Transform tool is useful because it combines all possible transform operations in a single tool, but I generally recommend that new GIMP users stick to the specific transform tool they need.
Switch to the Rotate tool using the keyboard shortcut Shift + R. You can also find it nested under the Unified Transform tool with the other transform tools, you just have to right-click or long-press on the Unified Transform icon to see the full list (shown above).
The key setting that determines what part of your image gets rotated is right at the top of the Tool Options panel, once the Rotate tool is active. It’s definitely under-appreciated, but you want to make sure that it’s set to Layer, as it is in the example below.
Click anywhere in the main image window to begin the rotation process. In this example, I want to adjust the rotation of Wilber’s paintbrush bristles a little bit. Not for any particular reason, but just because I can. Image editing projects are like that sometimes, lol.
GIMP shows the Rotate tool popup in the top corner of the image window and adds a boundary around the part of the image that will be rotated. It also adds a quartered circle, which sets the pivot point. Any time you rotate an object in GIMP, it rotates around the pivot point.
I’ll move the pivot point to the base of the brush area, and the rotation looks much more natural. If you want to reset everything, simply click the Reset button. Once you’re satisfied with how it looks, click the Rotate button to finalize the transform.
Rotate Your Selection Area in GIMP
It’s also possible to rotate just the selection that you’ve made, not the actual image data. Of course, I already gave the secret away in the section above: you just have to set the Transform setting to Selection instead of Layer.
Then you just follow the same steps to apply the rotation, except GIMP will only rotate your selection area instead of the actual image content itself.
This is useful in a lot of projects, even if you might not see the value at first. It’s useful when creating a new shadow behind an object or any other situation where you need to create a new element based on an existing shape in your image.
That’s everything you need to know about how to rotate a selection in GIMP!About Thomas Boldt