Basic photo editing with GIMP
If Microsoft Paint isn't enough for your photo-editing needs, GIMP is the next logical step. It's totally free, open-source, and can go toe-to-toe with Photoshop—at least in terms of basic image manipulation. Need to crop a photo? Look no further. Want to add some basic filters or effects? GIMP has you covered.
Despite being free, it's actually surprisingly intuitive for anyone familiar with image-editing software. If you're comfortable with any feature-rich photo editor, the learning curve for GIMP should be fairly short. Regardless, whether you're a Photoshop pro or an image-editing newbie, we'll hold your hand while you learn the ins and outs of GIMP.
Getting Started
Keep calm and turn Single-Window Mode on.
Before you even import an image, we recommend setting GIMP to Single-Window Mode. It'll consolidate all of the controls and sub-windows into a single, unified window. For beginners, it's a life saver and will help keep you organized. The main downside here is that you can only manipulate one image at a time, although GIMP provides a handy tab-view to easily switch between images.
That big white circle is in its own, distinct layer and hasn't changed the original image.
You'll also want to be familiar with the Layers Dialog, which displays all of the different layers of an image. This is one of GIMP's (and most other powerful photo-editing software's) greatest features because it you lets separate images into multiple parts that you can manipulate individually. If you want to annotate an image or edit only parts of it, you can create a new layer (right-click in the Layer dialog and select New Layer) to keep your drawings separate from the original image. Click the eye icon beside each layer to toggle visibility—this is handy for quick A-to-B comparisons. Also keep in mind that the order of layers matters. The uppermost layers are literally overlaid on top of the lower layers.
The Tool Options dialog gives you immediate access to tool-specific settings like size.
We haven't gone over specific tools yet, but it's important that we introduce the Tool Options dialog. It automatically updates with options specific to whatever tool you've currently selected. If you're on the Paintbrush Tool, it will present you with options for settings like Size, Opacity, and Brush types.
As with most programs, basic hotkeys are all functional in GIMP. Ctrl+Z lets you undo the last edit, Ctrl+S lets you save the image, and Ctrl+O lets you open an image. We'll cover tool-specific hotkeys later in the guide.
Tools
Here's GIMP is all of its open-source glory.
The heart of any photo-editing software is the toolbox or toolbar. GIMP presents this by default as a three-by-eleven set of colored icons on the left side of the window that denote the essential tools and functions of the software. We won't cover everything, but we'll go over all of the basics.
The most important tool is probably the Rectangle Select Tool. It's the first one on the toolbar and lets you select portions of your image by clicking and dragging an expanding rectangle—think Windows desktop style. Once you've drawn a selection box, a square will appear in each corner. Grab a square and drag in or out to expand or shrink the selection box. Once you've got a section selected, you can copy, cut, fill with colors, or do pretty much anything else you'd like. The Ellipse Select Tool should be self-explanatory at this point—it does the same thing, but with ellipses instead of rectangles. At any point, Ctrl+Shift+A will deselect everything and Ctrl+A will select everything in the image. If you want to make multiple selections, hold Shift as you draw your selection box. Hold Control if you want to remove parts of your selections.
The Free Select Tool is on the left and the results of the Fuzzy Select Tool are on the right.
Next up are the Free Select Tool and the Fuzzy Select Tool. Just like the aforementioned tools, their names are fairly descriptive. The former lets you connect lines to select a region defined by a limitless number of straight lines. Simply click anywhere to drop an anchor point and click somewhere else to connect that point with another. Think of it as a game of connect the dots. Once you're done, you simply click the first circle you created to finish up the selection. At any point you can also press Enter to finish the selection. The Fuzzy Select Tool will use a built-in algorithm to select sections of the current layer on the image by color. Click an area of the image that's yellow and the Fuzzy Select Tool (or Magic Wand) will grab everything that's yellow. If you aren't getting acceptable results, try tweaking the Threshold setting in the bottom left Tool Options window. Increasing the threshold increases the sensitivity of the tool and will usually expand the area selected.
All we want are those tires and a bit of the step ladder next to it.
The Crop Tool is super simple and lets you easily crop images by selecting a section of an image with a rectangular selection tool. Press Enter to perform the crop. As with the selection tools, you can use the square in each corner to resize the selection.
13.81 isn't the prettiest angle, but it's fine for demonstration purposes.
As with the Crop Tool, the Rotation Tool is relatively simple and doesn't take much know-how to operate. Simply create a selection or select a specific layer and click-and-drag the item in either direction to rotate it. A window should pop-up with options asking you to confirm the rotation. You can select a specific angle and adjust the Center X and Y coordinates before confirming the rotation.
The Scale Tool makes scaling easy.
Image resizing is also a cinch with GIMP's Scale Tool. Select the tool and click your image to resize. A pop-up dialog presents options for width and height in a variety of measurements. Click the link icon to lock the dimensions—this is helpful if you don't want to stretch the image outside of its original aspect ratio.
Click on to the next page to read about a few more tools and how to get your images out of GIMP.
Tools Continued
The Color Picker Tool is great for finding exact colors.
Another essential tool is the Color Picker Tool (or Eyedropper). As its name suggests, the tool gives you the ability to click anywhere on your image to find the color at that exact point. By default, the tool will set your foreground color as the color that you've clicked on. You can click the white double-sided arrow (see the image above) to swap the foreground and background colors. Click on the foreground or background color to open the Color Selector.
Fine-tune your color selection with specific RGB or CMYK values.
After selecting a color, you can use it in conjunction with the Pencil, Paintbrush, Bucket Fill, Airbrush, and Ink tools to draw on or annotate your images. Keep in mind that if you've got an area of your image selected, your tools will only function within the boundaries of the selection. Use the Eraser Tool to get rid of any marks you've made to the image or to erase parts of the image itself. Make sure you're in the right layer before you start making any marks or erasures.
The Text Tool in action.
The Text Tool is also super useful for adding text to any image. Click anywhere on an image to create an undefined textbox that will expand to fit your text. Click and drag to create fixed text boxes that will wrap text to fit. Type your message or labels and click another tool or anywhere else in the window to finish. When you click on the text, GIMP will automatically re-open the text editing window, which has options for adjusting the font face, size, baseline, kerning, and color. By default, GIMP will create a new layer for each instance of text, so the words won't be permanently added to the image. This means that you're free to move text around the image with the Move Tool (denoted in the toolbar by two intersecting arrows).
Behold the glory of the Clone Tool in action.
The Clone Tool is one of GIMP's supremely cool features. It's used to clone a section of an image and overlay that section onto another part of the image. This can be used to correct mistakes, as seen in the image above, or to remove imperfections on photos, such as acne. Simply select the Clone Tool and set a reference point by holding Ctrl and clicking on the image. Then click and hold (as if using a paintbrush) to apply the selection area of the reference point onto the area underneath the cursor.
Another advanced feature is the Heal Tool. It's a lot like the Clone Tool, but it uses a hidden algorithm to analyze the destination before applying the source area. Use it for jobs where the clone tool just isn't working. This tool works really well for smoothing subtle features like wrinkles and can also remove acne, freckles, or small marks.
Exporting the Finished Product
We don't even recognize half of the potential output file formats supported by GIMP.
Once you're done working on your image and you're happy with the results, make sure you select Export As… in the File menu—don't click Save or Save as unless you're happy with the original file format. This option provides you with a laundry list of potential file formats. Once you've clicked Export, you'll be presented with some more options that usually include a Quality setting and an estimation of the final file size.
Learning More
There's a whole host of features and capabilities—most notably: plug-ins—that we haven't even touched on in this crash course. Fortunately, there are resources available for people interested in diving deeper. Head on over to the GIMP website and check out the official User Manual for an abundance of in-depth information.
Already a GIMP power user? Tell us your favorite features or suggest some tips in the comments below!