Boost colour and sharpness of your images in GIMP
We all know the feeling when we take a photo of something which in real life looks impressive, but somehow your camera doesn’t manage to deliver the feeling in the photo. Colours look dull, level of sharpness is not as desirable, and details are not that visible. Instead of throwing your photo away, try to add life to your image in GIMP in a few simple steps.
In this tutorial you will learn how to:
- Boost and make colours warmer (use curves)
- Improve contrast (use levels)
- Increase sharpness (use different sharpening methods)
- Lighten separate areas of the image (paint with soft brush and use layer modes)
I chose a photo I took in a local zoo, but I didn’t like it until I edited it in GIMP. Now I’m going to show you how.
Open GIMP, then select your image in the folder, next drag and drop it right on the canvas. Or go to File / Open / find your image / Open.
Duplicate your image by right click on the image in the layers dialogue and call it Color.
Pick Curves Tool from Toolbox or go to Colors / Curves.
In the Channel options choose Red Channel and create a curve as shown in Fig 1. Next create the same curve for Green Channel see Fig 2. And finally create a curve for Blue Channel as shown in Fig 3.
Notice that for Red and Green Channels you need to create a curve which is going from rising to falling, but for Blue Channel you need to lower the line. Also pay attention to where my dots are.
Another thing to keep in mind is that colours vary from photo to photo, so you might need to make smaller or bigger curves to achieve desired degree of colour changes.
I prefer to do every new operation on a new layer so that in case I don’t like the result, I can always delete it and do the operation again. If you want you can do the same.
Duplicate the layer Color, next pick Levels Tool going to Colors / Levels. Move Highlights slider to the left and Shadow slider to the right see Fig 4. To see before and after results just untick Preview, then tick it again. When you are happy with results press OK.
You can check the changes you have done so far to the image by clicking on the Eye icon next to layer, it will hide the layer showing you only visible layers (which are marked by the Eye) see Fig 5.
To further boost colours in your image go to Filter / Eg / Color Vibrance. Leave setting as they are.
Create a New Transparent Layer by clicking on the first icon at the bottom of the layer dialogue or right click on the top layer choose New Layer / Transparency.
Tools / GEGL Operation / Vignette. Here you have to decide for yourself which setting to choose for your image. I usually change only Radius and Softness. For my image I chose: Radius – 1.85 and Softness – 0.70. for this particular operation I would say that “less is more”.
Right click on the top layer and choose New from Visible. It will create a new image made from all the layers see Fig 6.
Tip: If you want to lighten some areas of your image, there is an easy way to do it.
Create a New Transparent Layer and put it to Overlay. Take a big soft brush, the best is with 0% Hardness, reduce Opacity to about 15%, choose size according to your image (the larger the image, the bigger should be the brush) and paint on the areas you want to brighten. For my image which is 3667x2341 I set size to 400.
Now merge all the layers going to Image / Merge Visible Layers / leave settings as they are/ Merge.
As the final step we need to sharpen our image. There are a few ways to do it.
- Filters / Enhance / Unsharp Mask. Radius - 1.3 Amount – 0.30 Threshold – 4.
- FX-Foundry / Photo / Sharpen / Eg High-Pass Filter Sharpen. Sharpening Strength – 5.00. You can change the Opacity of the sharpened layer to your taste.
- FX-Foundry / Photo / Sharpen / Luminosity Sharpen. Leave setting as they are.
Flatten your image going to Image / Flatten.
Time to save the edited version. Go to File / Export (I’m using GIMP 2.8) find folder / Give your image a name / Export.