I am a passionate self educated photographer who is always trying to learn even more about my passion.
How to Use GIMP 2.8+: A Step-By-Step Process
If you've been wanting to edit your photographs but don't know how, I will show you how to do so using GIMP 2.8 or later versions. It is for the basic editing of levels, brightness, contrast, and sharpness.
For those of you who have never heard of GIMP, it is a free image-editing software program. This snapshot from the website best describes it:
"The Free & Open Source Image Editor
This is the official website of the GNU Image Manipulation Program (GIMP).
GIMP is a cross-platform image editor available for GNU/Linux, OS X, Windows and more operating systems. It is free software, you can change its source code and distribute your changes.
Whether you are a graphic designer, photographer, illustrator, or scientist, GIMP provides you with sophisticated tools to get your job done. You can further enhance your productivity with GIMP thanks to many customization options and 3rd party plugins."
This tutorial presumes that you have downloaded and installed your preferred version of GIMP onto your computer. It also presumes that you have completed your basic setup and are comfortable navigating the setup. GIMP updates and releases come out on an irregular basis, depending on when the developement team feels that they are ready for release. The version of GIMP that I am using is GIMP 2.8.10, and I have been using it for quite some time now. The current version is GIMP 2.8.22 and probably has some changes and upgrades I am unaware of.
The very first step after opening your version of GIMP is to select and open an image to be edited. There are two ways: One is described below and the other, the way I most often use, is to simply click on one of my photographic images that I have downloaded onto my computer and drag it to the GIMP editing screen. This almost always works exactly as expected by me, with the only delay being to click on a warning message for a vertical (portrait) image that GIMP may read as a horizontal (landscape) image to change it to the desired orientation.
1. Open the Image
There is another way to open your image in GIMP that is nearly as quick and easy as the click-and-drag method. Simply left click on the "File" dropdown menu tab. Then, left click on the "Open: sub menu. A new sub menu opens that allows you to choose the correct folder and file to open. (Alternately, press and hold the Control key while pressing the O key) and follow the steps above.
You should see something similar to the above screenshot. Navigate your way through the folders to the image you want and open it in GIMP. For the purposes of this tutorial I chose this image to edit:
2. Change the Orientation
Once the photo was initially opened, I wanted to change the orientation from landscape (horizontal) to portrait (vertical) using the pop-up message box.
3. Edit the Levels
To begin editing, I clicked on the "Colors" Tab, then the levels sub menu tab, which brought up the dialoge box above.
On the dialogue box, you have multiple choices to edit your image to create the result you want.
- In this case, I chose to start by clicking and dragging on the left-side intput slider triangle to darken the image to level 30 and clicked on the right-side slider triangle to lighten the image to a 240 level.
- I chose not to make any corrections using the gamma correction box between the input sliders. The gamma correction slider works the same as the sliders for both the input and output sliders.
- You also have the available option of adjusting the RBG scale on the image. This is easily accomplished by clicking on the channel dropdown menu and choosing the base color you want to edit. The Red, Blue or Green channel can be adjusted using the same sliders and procedures you used to adjust the levels in your picture. In this case I chose to make no adjustments to the color channels.
- I clicked the "Okay" button to accept the image as it currently was.
Please Note: I frequently click on the "Auto" button in the dialogue box. If I am satisfied with the result, I simply click the okay and proceed to the next editing step.
4. Adjust the Brightness/Contrast
The next step I took was to click on the "Colors" tab again and then click on the "Brightness-Contrast" tab, which brought up the option above.
- I slid the Contrast slider to the right, setting the contrast level to a +10 setting. Normally, I almost never adjust the Brightness-contrast slider more than a +10 or -10 at this point.
- I then clicked the okay button to accept the resulting image. The final step I took with this image was to use an unsharp mask to create a sharper Image. You can find the unsharp mask by clicking on the "Filters" tab, selecting the Enhance sub menu, and then selecting the unsharp mask from the resulting dialogue box. It should look similar to this below.
5. Leave the Radius, Amount, and Threshold
I normally leave the radius, amount, and threshold pictures at the current settings. They seem to work best for me in most cases. If necessary, you can adjust them with the sliders at need or whim.
The order of the steps involved here are what I typically follow to edit my photographs. They are not written in stone, and I would encourage you to experiment until you find out what works best for you. Please always remember that the technical aspects of photography are only a part of the art form, and it is what you are trying to convey or show that is important.