Gimp For Software Developers: Troubleshooting and Quick Tips

Last updated:

Change image mode to RGB

If you're trying to change the Hue/Saturation (that's one way to change the colours on an image) on one of your PNG or GIF images but you keep seeing the error message

XYZ operates only on RGB color layers.


XYZ does not operate on indexed layers.

Go to Image ➔ Mode ➔ RGB.

  • credits pgimeno on #gimp @ freenode

Retrieve missing toolbox

Go to Edit ➔ Preferences ➔ Window Management And then click on Reset Saved Window Positions to Default Values

Create hotkeys for commonly-used functionalities

Go to Edit ➔ Keyboard shortcuts

Switch to single-window mode

Go to window ➔ Single-window mode

Make selection transparent

  • Make sure your image has an alpha channel

    • Go to the layers menu, right-click on the layer and choose Add Alpha Channel
  • Select the area you want to make transparent and hit delete (not backspace)

In GIMP, how do I make part of an image transparent manually?

Extend a layer to make the background larger

  • Increase Layer Boundary size (Layer ➔ Layer Boundary Size)

  • Adjust Canvas Size

    • Either (Image ➔ Fit Canvas to Layers) or adjust it manually via (Image ➔ Canvas Size)

Dialogue & Discussion