GIMP tutorials

Draw a rectangle or a circle

  1. In the toolbar select either the rectangle or circle select tool:
  2. Click and drag around the area where you’d like the rectangle/circle
  3. Change the colour as desired by double-clicking the colour palette:
  4. Go to the Edit menu > Stroke Selection > adjust Line width as desired > Stroke

Blending two images

http://boitblog.blogspot.com/2007/07/blending-two-images-with-gimp.html

Adding transparency to an image

http://graphicdesign.stackexchange.com/a/6460

Making the background uniform

For example, if you scanned a picture of your signature on a white page, getting just the signature and getting rid of the background scan so it’s completely transparent

  1. Layer > Transparency > Threshold Alpha… > OK

Or:

  1. Layer > Transparency > Alpha to Selection
  2. Select > Invert
  3. Edit > Clear (or press the Delete key)
  4. Select > None

Make transparency show up as grey checkerboard

Edit > Preferences > Display > Transparency > Mid-tone Checks

Creating a new layer from selection

  1. Make the selection
  2. Edit > Copy
  3. Edit > Paste as > New Layer

Select a region using edge detection

  1. Click on the Scissors Select Tool

  2. Click where you want to start edge detection

  3. Drag the first point as desired

  4. Click to add the second point and drag as desired

  5. Continue until you reconnect to the first point

  6. Drag points to make further adjustments as desired

  7. Click on the inside to turn it into a selection Note: this will prevent you from making further changes