Image manipulation (The Gimp, DigiKam)

How to make a portion of an image transparent using The Gimp

Sometimes you want to make a certain portion of an image transparent.

This is for instance to make an image look good, placed on a background on a web page.

Remember that only .GIF and .PNG support this feature, NOT .JPG!! This can easily be done using The Gimp.

  1. Open your image in the Gimp. File -> Open.
  2. Right click the image and go to LAYERS then ADD ALPHA CHANNEL. This is the transparency layer.
  3. Right click on the image again and go to SELECT and then BY COLOR.
  4. Now click on the color in the image you want to be transparent. These colors will now show up outlined.
  5. Right click on the image again and go to EDIT and then down to CLEAR. 
     This should now erase the outlined color you just picked from the image and the "transparent gimp checkerbox" should show through. 
     This is the Gimps way of showing you that section is now transparent.
  6. Right click on the image and choose SAVE AS and make sure to save as a GIF file if you want the transparency to work on the web. 
     Select CONVERT TO INDEXED if necessary. It is also possible to SAVE AS... PNG
  7. That's it!