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GIMP (GNU Image Manipulation Programme)
- Sarah Crofton
- Abdulghani1,N (Unlicensed)
- Steve Bond (Unlicensed)
GIMP (GNU Image Manipulate Programme) is a free, open-source alternative to expensive software like Adobe Photoshop. It’s powerful enough for professional graphic design, but also a great solution for basic image-editing.
The sections below will guide you through the most common tasks for which you may wish to use GIMP in your work. You can also find additional guides and tutorials at the GIMP project website.
Getting started
Installing GIMP
GIMP is free to use and works with Windows, OS X, and Linux operating systems. The latest version of GIMP is always available for free from the GIMP website.
The images in the tutorials below show GIMP 2.10 for Windows, but the GIMP interface is very similar for all operating systems.
See our copyright guidance on Creative Commons and Open Access images for your projects: http://lti.lse.ac.uk/copyright/copyright-images-multimedia/
Navigating the interface
When you open GIMP for the first time you’ll see a workspace surrounded by control panels providing quick access to the many tools, brushes, and editing methods available.
On the right of the interface (No. 1 above), you will see a toolbox full of small icons, like paintbrushes and scissors, representing different editing and transformations that can be done in GIMP. When you first install GIMP you may have some trouble finding the tools you need, as several may be grouped together to save space. Expand the instructions below to see how to manage and ungroup them.
Adjusting the interface for accessibility
The default theme for GIMP is dark and the tool icons are small. Before using the software you may wish to adjust your settings.
Resizing images
Most cameras and scanners produce very large images - both in terms of their dimensions and their file-size. GIMP makes it simple to check the true size of an image file and adjust it for use in printed documents or on websites.
One-minute video
‘Resizing an Image with GIMP’ (Opens in new window)
Checking the true size of an image
Some programmes – including Word and PowerPoint – shrink images for display while still saving them at full size, increasing the overall size of a file. You can see the true size of an image by opening it in GIMP
Making an image smaller
GIMP makes it very simple to scale images down while keeping them in proportion. You can also choose the best resolution for various web or print uses.
Making an image larger
Images increased to larger than their original size will always have some loss of quality. The more you try to enlarge an image the blurrier or more pixelated it is likely to become. It is always better to avoid enlarging images whenever possible. However, GIMP has some features built-in to combat loss of image quality.
Saving images
In GIMP there are two save options - one that allows you to keep working on the image as a GIMP project and one that turns the finished project into a standard image file.
One-minute video
‘Saving and Exporting’
(Opens in new window)
Saving vs Exporting
GIMP saves images in a file format called ‘.xcf’. Files in .xcf format can be opened and edited with GIMP but need to be exported to a different image format for use in documents and on websites.
Choosing a file format
GIMP allows you to choose from a huge array of image types when you export your file. In most cases you will only need to consider the following two options:
JPEG (.jpg/.jpeg) is a good choice for keeping image files small for use on websites. JPEG format compresses an image trading some details for smaller file size. It’s a good choice for photographs and colourful images.
PNG (.png) creates slightly larger files, minimising loss of detail. It’s a good choice for diagrams and images where crisp details are important. PNG files also support transparency, which JPEGs do not.
Converting image formats
You can also use GIMP’s export function to change the file format of any supported image. For example, you may have a scanned file with a .tiff extension that you wish to turn into a PNG for use on Moodle.
Cropping, flipping, and rotating
Some of the most useful tools in the GIMP toolbox are the cropping, flipping, and rotating tools.
One-minute video
‘Cropping Images’
(Opens in new window)
Cropping an image
GIMP’s crop tool can be used to cut an image down to size.
The GIMP crop tool
Uncropped image
Cropped image
Flipping an image
GIMP’s flip tool can invert an image or a section of an image along its vertical or horizontal axis.
The GIMP flip tool
Unflipped image
Flipped image
Rotating or straightening and image
GIMP’s rotate tool can be used to spin an image or a section of an image around a central pivot.
The GIMP rotate tool
Unrotated image
Rotated image
Retouching Images
GIMP has many filters that can be used to adjust the brightness, sharpness, and contrast of your images. You can also quickly edit the hue and saturation profile to change the colours of all or part of your image.
One-minute video
‘Grayscaling Images’
(Opens in new window)
Sharpen and blur
To sharpen an image click Filters > Enhance > Sharpen and adjust the slider until you are satisfied. Then click OK.
To blur an image click Filters > Blur > Gaussian Blur and adjust the slider until you are satisfied. Then click OK.
No filter
Filters > Enhance > Sharpen
Filters > Blur > Gaussian Blur
Hue, saturation, lightness
To adjust the levels and saturation of colours in your image click Colors > Hue-Saturation… and adjust the hue, lightness and saturation sliders until you are satisfied. Then click OK.
Hue adjusted towards pink
Lightness increased
Saturation decreased
Brightness, contrast
To alter the balance and contrast of the bright and dark areas of your image click Colors > Brightness-Contrast… and adjust the sliders until you are satisfied. Then click OK.
No filter
Brightness up / Brightness down
Contrast up / Contrast down
Removing small details
Sometimes you may need to remove a small detail or mark from an image. GIMP’s clone tool is a good option for this.
The GIMP clone tool
Image of paper with coffee stain
Coffee stain removed with clone
Adding text or logos
The best way to add text or a logo to an image is by using layers. This leaves the image underneath unchanged and makes it easier to move or change your text/logo.
One-minute video
‘Adding Text to Images’
(Opens in new window)
Adding a logo
If you have a logo or watermark file, you can easily add it to your image as a new layer in GIMP.
Adding text
Sometimes it is useful to be able to add text to images, charts, or graphs. GIMP has built-in tools for creating and editing text layers.
Improving text legibility with labels
You can make your text more legible by adding an extra layer between your text and your image and filling it with a colour to form a background label for your text.
One-minute video
‘Increasing Text Legibility’
(Opens in new window)
Drawing Shapes
Drawing tools are useful for circling details and adding guiding arrows etc to images. In GIMP there are two kinds of drawing tools.
The paintbrush or pencil tools can be used for making straight lines or drawing freeform.
The selection tools can be used for drawing polygons.
Using selection tools for polygons may be confusing at first if you are used to other drawing programs, but is easy and useful once you learn how.
Free-form and Straight Lines
Polygons
Quick-start videos
Adding Text to an Image with GIMP [01:26]
Increasing Text Legibility on Images with GIMP [01:40]
Resizing an Image with GIMP [01:04]
Grayscaling Images with GIMP [00:43]
Cropping an image with GIMP [01:12]
Saving and Exporting Images with GIMP [01:49]
Further information
You can find additional guides and tutorials at the GIMP project website.
This 2-hour video covers all the basics and some more advanced concepts.
Request an additional tutorial
If you would like advice or instructions for an image-editing task not covered here please contact eden.digital@lse.ac.uk for advice.
These pages are created by the LSE Digital Education Team and licensed under a Creative Commons Attribution-ShareAlike 4.0 International License CC BY-SA 4.0