How to touch-up portraits with GIMP
by Nicu Buculei
This tutorial explores a few simple techniques to improve a portrait using GIMP. In particular, you’ll see a couple of new features introduced in the new GIMP 2.4, the Healing Tool and the Red Eye Removal filter.
We will start with the boring image on the left and get to the shining one on the right. Note that all images in this tutorial are available in a Flickr set.
Crop to the most interesting part of the photo
Don’t be afraid to cut the photo down to the most interesting part. Use the Crop tool to select the part of the photo which is meaningful for the viewer, in this case, her face. Here I activated guides for the Crop Tool using the rule of thirds to help me with the selection. (See the toolbox for activating these guides.)
Note: The rule of thirds is a guideline used in the composition of images, including in painting and photography. Dividing an image in thirds both horizontally and vertically will create four points of intersection that can be used to align the image to create more tension, energy, and interest.
Remove red eye
If the subject has red eyes, use the Red Eye Removal filter (Filters > Enhance > Red Eye Removal). Zoom in and adjust the slider as needed.
The best option is to not need the red eye removal tool at all. The red eye effect is created by the reflection of the camera’s flash light in the inner part of the eyes. Avoid using the flash when you can, or use your camera’s portrait mode, which will minimize the red eye effect.
Adjust the levels
Improve the dynamic range of the photo using the Levels dialog (Colors > Levels). If you know how to use the tool, move the black and the white sliders for Input Levels to cover the histogram values and the middle sliders to the left or right if you want to enhance the white or black. If you are not familiar with histograms, the Auto button is your friend. It will automatically adjust the levels to what GIMP thinks they should be. This can, however, be wrong, so it’s a good idea to play with the sliders to get a feel for adjusting them yourself.
Adjust the color curves
You can enhance the photo further by adjusting the Color Curves ( Colors > Curves). For a natural image, an “S” curve will do wonders. Of course, you can do a lot more with this tool, such as adjust brightness and darkness, or use it to adjust each color channel (red, green or blue).
Roll over the palette to see the results of the adjustment.
Remove imperfections with the healing tool
Next, correct large skin imperfections (wrinkles, blemishes, pimples) with the Healing Tool. It works similarly to the Clone Tool by defining a source and a destination area, but it will average the values for a smooth result. Zoom in and choose a brush size as needed.
Note: It’s useful to change the source area (by clicking while holding Ctrl) frequently, to have the source as similar as possible with the destination.
 |
Roll over a small image to enlarge it.
|
Enhance detail
To enhance the photo details, use the Unsharp Mask filter (Filters > Enhance > Unsharp Mask). Use small values.
Roll over the palette to see the results of the adjustment.
Adjust color balance
The face in this picture is a little too red, so I used the Color Balance dialog ( Colors > Color Balance) to reduce the redness a bit. As the opposite of red is cyan, the photo turned somewhat blue, so I then reduced the blue a bit.
Whiten teeth and eyes
To whiten teeth or the whites of eyes, use the Free Select Tool (lasso) with Feather edges (a value of 5 is enough) so you don’t need very precise margins, and select the area to whiten. Then Desaturate (Layer > Colors > Hue-Saturation) them a bit.
 |
Roll over a small image to enlarge it.
|
Smooth skin
The next step is to make the skin smoother, but be warned, this is a dangerous tool. Abusing it may destroy your photo. Turn on the Quick Mask (Select > Toggle Quick Mask), and with a black foreground and white background, use the Eraser to remove the red mask covering the skin, while avoiding the mouth, hair, eyes, and eyebrows. If you delete too much, reapply that part of the mask using a brush. When you’re ready, turn off the Quick Mask, and you’ll see the skin selected. Use the Selective Gaussian Blur (Filters > Blur > Selective Gaussian Blur) with small values to smooth the skin.
|
Roll over a small image to enlarge it.
|
Note: If you use large values for the Selective Gaussian Blur, you may get an artificial “plastic” effect. If the photo is very noisy, try a Selective Gaussian Blur over the entire photo, but be careful not to destroy the small details and get an even worse “plastic” result.
Add some glow
One last step: add some glow to the photo. Duplicate the layer (Layer > Duplicate Layer) and apply some Gaussian Blur (Filters > Blur > Gaussian Blur) to the duplicate. Also on the duplicate layer, adjust the Color Curves (Colors > Curves) and make the image very bright. Then set the Layer Mode to Soft Light. (Also try other modes for different effects). You can see in this example how the effect can make the photo very bright. When the result is too strong like this, reduce the opacity of the upper layer to tone it down a bit.
 |
Roll over a small image to enlarge it.
|
Remember what we started with and see what we got as end result. The differences are quite amazing.
It’s not hard to enhance a photo, and you should do it with all those photos you care about. A few small steps can make a difference, and GIMP has all the tools you need for the job. But be careful not to abuse them and get something worse. Remember that you don’t have to use every step in this tutorial for every picture. You may choose to use only one, or nearly all, dependent on your photo.
October 12th, 2007 at 3:56 pm
Nice tutorial!! i hope to see more in future!
October 12th, 2007 at 9:04 pm
Folks interested in the gimp should also check out the video podcast at http://www.meetthegimp.org/
October 14th, 2007 at 7:24 am
Nice tutorial, thanks! Btw, that photo seems to be from Romania. You can see the “national car” in the background: DACIA!
October 14th, 2007 at 9:03 am
Great howto, thanks a lot.
October 15th, 2007 at 12:12 am
Cristian, sure the photos come from Romania, didn’t you noticed the author’s name?
October 15th, 2007 at 5:39 pm
Pretty Woman – uhm I mean yeah, good howto!
Just wondering nobody mentioned it. ^^
October 17th, 2007 at 7:22 am
good article, good application, good author
October 17th, 2007 at 10:55 am
Great tutorial!
Building off of Cristian’s comment, I think I would further alter the photo to blur the view out the back window so that we are not distracted from the subject.
October 17th, 2007 at 4:45 pm
Excellent article. Very valuable, it has inspired me to have a bash at this
October 17th, 2007 at 11:49 pm
Steve, you are correct, blurring the background a bit is something useful in a lot of cases, I didn’t include it here only to keep the length of the article reasonable.
To do it, use the Quick Mask just like in the step where I used Selective Gaussian Blur for the skin but select the background and then apply a slight Gaussian Blur, for the photo used here I guess a value of 3 or 5 is OK.
October 18th, 2007 at 12:10 am
Update: sorry, for Flash, but here is a screencast about the background blurring: http://youtube.com/watch?v=LSPAEDcyb2Q
October 29th, 2007 at 6:48 am
Just a quick note about red-eye. Using the portrait mode on your camera will have absolutely no effect on whether red-eye is visible or not. It is caused by the flash being physically too close to the lens. This effect is worse with longer focal lengths (commonly used in portraits) because the longer shooting distance results in an even smaller angular distance between the lens and the flash. The only way to truly get rid of red-eye is to physically move the flash away from the lens or make it bigger and more diffuse. You just can’t do that with a built in flash, so you’re stuck using a red-eye reducing mode that pre-flashes or blinds your subject with a bright light that causes their iris to close down, thereby reducing (not removing) the effect.
October 30th, 2007 at 10:29 pm
Just wonder why Redhat Magazine have such related article?
October 31st, 2007 at 12:57 am
Why not? All the process is made with GIMP 2.4 running on Fedora, which Fedora is both a Red Hat project and the upstream for RHEL.
Consider it as a how to use your Red Hat desktop at its maximum potential.
November 7th, 2007 at 2:34 pm
Hi
nice tutorial.
If I want to cut around a big object, like a body, I usually use the path tool and then create a selection from it. This is usually quicker than using the brush or eraser.
Another thing is that I usually copy the layer before I do something. After I did my changes I can switch the layer visible and invisible. This will show what your changes realy did to the image (realy improved it or made it worse).
November 8th, 2007 at 1:28 am
Sure, there are quicker ways, but the Quick Mask offer the greatest accuracy.
Speaking about quick ways, have you checked the SIOX foreground selector tools? Is fast and nice (but not perfect).
November 9th, 2007 at 5:07 pm
How about composing your photo properly so it doesn’t need to be cropped?
November 9th, 2007 at 10:22 pm
Nice tutorial thanks.
November 12th, 2007 at 2:04 am
Fergal wrote:
How about composing your photo properly so it doesn’t need to be cropped?
Yup, that would be ideal but in the real life it does not happen often. This is why I think is important people should not be afraid to crop and throw away useless part of a photo.
December 10th, 2007 at 12:15 pm
Me gustaría saber quien es la chica que esta en la foto, la verdad es que es muuuuuy wapa, saludos por el trabajo del gimp que me lo he leido bastante bien
Gracias
Juan P
February 2nd, 2008 at 8:36 pm
i used this tutorial for my first attempt at photo editing for the purpose of portrait enhancement and i really found it helpful! thanks
March 26th, 2008 at 4:51 am
thanks Nicu, very nice tutorial.
March 28th, 2008 at 8:21 am
Thanks a bunch, the tutorial helped me a lot. Keep up the good work!
April 17th, 2008 at 6:01 pm
Excellent tutorial. Thanks, Nicu. Sólo me rio de todos los que no pueden evitar poner atención el etema del artículo… las mujeres lso vemos como bebotes, jajaja-
May 10th, 2008 at 8:53 am
I found your site on technorati and read a few of your other posts. Keep up the good work. I just added your RSS feed to my Google News Reader. Looking forward to reading more from you.
July 1st, 2008 at 1:24 pm
Thanks a lot for this. I’m so dense when it comes to this sort of thing and you helped me out
July 26th, 2008 at 3:23 am
back pimples
if you’d like to ask some one else how much they like this post i think the answer is goingto be.. very much, an original blog
October 29th, 2008 at 11:35 pm
Wow, it’s comprehensive and easy to follow. I have corrected 5 photos in split second. Thanks for sharing ^^;
November 19th, 2008 at 5:05 pm
[...] Red Hat Magazine: How to touch-up portraits with GIMP Oct.15, 2007 in Fondos Red Hat Magazine published this week-end my How to touch-up portraits with GIMP, it is a tutorial about photo enhancement I wrote as promotion for both GIMP 2.4 and Fedora 8, which will include the new GIMP. [...]
November 27th, 2008 at 10:48 am
Thanks for a very good, clear tutorial. Very well presented too, using roll overs to good advantage. More like this please.