Sunday, 20 March 2011

Part 3 - Improving your photos with GIMP - Colour Balance and Saturation

PS: I am still learning about GIMP (just like you!) so I don't profess to know everything. If i make a mistake, or you have a better way of doing things, please leave a comment below! I love to learn to make my photography better.

Today's post is long enough to be two separate posts (sorry about that!) but I thought I should keep colour balance and saturation together as they tend to go hand in hand. Last post I explained colour curves and showed you how to eliminate greys and brighten your images. The aim of today's post will be to correct colour balances in images. 

Colour Balance
The reason why we correct the colour balance is because the way our camera detected the white (or highlights) in our image was incorrect. This is called 'white balance' on a camera and 'colour balance' when you adjust it in post production. Most point and shoot cameras have inbuilt preset white balance settings which can be changed  (cloudy, incandenscent, direct light etc) through the setting menu and all DSLRs have a manual setting in which you can change the white balance as well as presets (the top of the range pro cameras can be purely manual as well with no presets - $10K+ (!)).

Basically the different settings compensate for the 'type' of light that you set and adjust the colour temperature to make sure that what is white in a scene is recorded as white by adjusting the relative proportions of the primary colours, red green and blue. For example, the incandescent setting adjusts and produces a colour temperature that is more 'cool' or blue than say, the cloudy setting, which produces a warmer colour temperature. There are many indepth reviews and guides about colour/white balance in photography magazines and online - I have put a few links up to good guides in my 'Links' page. 

So now you have an understanding of what's going on we can now learn how to correct imbalances in your images! I've put an example of one of my photos below which has been taken indoors with the wrong white balance setting. It is way too blue - my mannekin's skin tone looks like an alien/zombie hybrid! Let's make her a bit more human looking :)

Within GIMP, the colour balance dialog can be found in the 'Colours' menu under (strangely) 'Colour Balance'. A dialog box like the one below should pop up. 

When I am editing colour balance, I don't tend to change the range for adjusting from the midtones. I find this gives me the best image, but depending on the image, you might find the other ranges need adjusting too. Experiment with what works best for you.

So, in my recycled glass necklace photo, I can see that the colour temperature at the moment is quite cool and blue. I can correct this by moving the sliders down the bottom of the dialog box more to the warmer ends - yellow and red. Red gives the skin tone a pink flush and yellow also adds warmth. I need to be careful not to overdo it though, or my photo can come out looking worse than it came in! Below are the results of tweaking the colour balance and the final positions of the sliders in the dialog box. She looks more like a vampire now - still a bit pale! :)

Saturation is what is sounds like - how intense a colour is. Think of it in terms of being misted with water (unsaturated) to jumping in a swimming pool (saturated). Sometimes, changing the colour balance doesn't cut it with correcting colour imbalances as sometimes one colour is way too dominant compared to others, or colours that are suppposed to be bright have somehow come out dull. In the image below, it too is quite blue, like the example above, and the yellow/gold tones have been washed out. 

Saturation can be changed in GIMP from the Colours > Hue - Saturation dialog box. It should look like the below. When you first open the dialog box it will have the 'master' setting selected - any changes to saturation, hue or lightness will affect all colours within the image.

I completely desaturated this below image, effectively turning it into a grayscale image by sliding the saturation slider all the way to the left. When you do this, you will notice that all of the colour boxes gradually more grey, until they are all completely grey. 

To alter different colours, click the circle 'checkbox' next to it. Then use the slider to change the saturation of each individual colour. Below is the example above after having the blue and cyan channels desaturated to some degree and the red and yellow channels saturated. You can see from the dialog box below that the blue channel has been completely desaturated (grey) and the cyan channel is also slightly grey.

HINT - If you change something you didn't want or make a mistake in any of the dialog boxes, pressing the 'reset' button on the bottom will reset the image back to what it was when the dialog box was opened - very useful feature!!

Next Post
I hop you found this tutorial helpful and please comment below if you want any clarification or if I have made a mistake! Next week, it's the last in the series and i'll be talking about cropping and resizing images specifically to make them great for viewing on Etsy. 

Also, please let me know if you would like a specific tutorial on something that you would like covered (filters, working with layers, creating banners, avatars etc). I'll be happy to help! 


  1. Thank you for this series, producing excellent photo's is not always - point and shoot!

  2. Thanks for these tips! I'm a GIMP user myself, and often go to the color - auto - white balance and just go with that. I do find that at times I need something else but am never sure what exactly to do :P

    I'm bookmarking this so I can experiment! :)

  3. Thanks for sharing. Feels complicated to me. I try to compensate for colours by putting something white and something black in every photo! (I cheat!) but it still never comes out really professional looking.

  4. @ Fairy Cardmaker-it's really truly not that just feels like it.
    Play around with it sometime and see!

  5. Great post! I don't use GIMP, which I assume is a specific software program? However, I do use other software that has similar controls. Your explanation is helpful.

  6. Hi,
    I use GIMP, but am not so good at "make-up-ing" pictures - the only worst thing is how I take pictures... I was trying to de-yellow this stuffed bunny picture: - and I used the tools you are suggesting... but I come up with something worse even. Instead of yellowish I got it greenish... yack.
    I would really be grateful for some tips for I have a lot of yelowish pictures (flashlite)...

  7. Sigh I just was about to post a long answer and my iPad ate it... I'll reply in more detail in the morning!

    Thanks for the replies and glad this has been so helpful!

  8. @Judy - GIMP stands for GNU Image Manipulation Program. No idea what GNU is though...

    @Kati - Please check your Etsy convos i've replied in more detail on there.
    To reduce the yellow tint that you are getting i would suggest:
    - changing the whitebalance or preset on your camera
    - Turn off your flash and take your photos in diffuse natural light or with a lightbox
    - Take your pictures on a neutral (white, grey, black) backgrounds
    - Within GIMP:
    - adjust the blue, cyan and red channels in colour balance.
    - Adjust the saturation of blue, cyan and yellow (up and down!).

    Thanks for the comments :)