Here is another article of our “GIMP tricks” series. This time you are going to learn a simple trick: how to make your teeth look really white on a photograph. By the way, perhaps it’s the right time to visit a dentist?

Author: @Cakper

First you will need an image of yellow teeth. Here you can download the one I used in this tutorial: The jaw image

1. Open the image you have downloaded or the one you want to correct. Toggle the view to “QMask” by pressing the little square shown in the picture below.

   

   The whole image should become red. Don’t be afraid, everything is OK.

2. Use the “soft” brush - Circle Fuzzy (here you can use 19 as the value). As a foreground color, choose white. It is used to mark the selection on the mask.
3. Now outline the tooth as it is shown in the picture below.

   

   It is not as simple as it may seem at first glance, so when you outline too much just switch the foreground color to black and correct the border.

4. When you are finished with outlining, to save your time, use a wider brush to color the rest of the tooth in the center.

   

5. If you successfully manage to color the whole tooth, toggle the view back to normal. Now the tooth is selected! This is the power of the quick mask view.

   

6. And now the most important thing in the tutorial!
   From the menu choose: Layer->Colors->Brigthness-Contrast.
   Set the Brightness to +80 and the Contrast to -10.

   

   These parameters are the ones I used here, but naturally you can experiment and adjust your image to your requirements.
   That’s the end! Easy, isn’t it?

   

   Of course, don’t whiten teeth one by one. To increase the speed of whitening the whole jaw, color the whole region you intend to whiten in the qmask view.

In my case, the final effect is like this:

Good luck!

Translated by titter, proof-read by Jake Conroy

This article has been first published in Gimpuj.info, a Polish online GIMP forum. You can see the original tutorial (in Polish) here: Wybielanie zębów [retusz cz1]. The article has been slightly modified compared with the original version by the PolishLinux team.