How to Fix Photos with Free, Open Source Software

Small business owners need great looking images on their websites and for their printed materials. If you want to make your images look their best, but you don’t want to spend a ton of money to do it, you’ve come to the right place. Read on.

One of the best open source graphics programs is called GIMP, which stands for GNU Image Manipulation Program (GNU refers to a whole ecosystem of free/open source software). GIMP runs on Mac, Linux, and Windows, and it’s open source and free of cost. We’ll go over different ways that you can edit your photos and images with GIMP.

Photo in need of red-eye removal

Figure 1: A nice photo of nice people with not-so-nice red-eye.

You can use GIMP to create original images or to edit photographs and images in nearly any image file format. It comes with a wealth of software “tools” such as brushes, pencils, airbrush, eraser, smudge, calligraphy, and a ton of special effects. It fully support Wacom drawing tablets, and if you haven’t tried a Wacom tablet you’re missing out, because it lets you draw with a stylus just like drawing on paper. And wonder of wonders, GIMP offers very good documentation, and you’ll also find a number of excellent GIMP books, so you can always find out how to do what you want.

A quick reminder before we start: Before editing your precious photos, always make backup copies first.

Install and Get to Know GIMP

Visit GIMP’s download page to find the installers for Mac and Windows. It’s already included in most Linux distributions.

GIMP is a little overwhelming the first time you look at it, but that’s the nature of image editing software: there are lots of cool things you can do with it. It’s worth learning your way around GIMP, because it is so versatile and just plain fun.

When you open it the first time, the default view has three separate detached parts: the Toolbox-Tool Options dock, the Edit Window, and the Layers-Brushes dock. Some people like it this way. If you’re more comfortable with a single-window view, you can have that too—just go to the Windows menu and click Single-Window Mode.

Note that the cursor changes according to where you place it. When you move it over the menus or toolboxes it changes to a normal cursor, and when you move it over an image in the edit window it changes to a tool. The default is the Paintbrush tool. If you accidentally make a mark with it, no worries because all you have to do is press Ctrl+z to undo, or use Edit > Undo.

How to Remove Red-eye

Figure 1 shows a photo of two wonderful people (hi Terry and Hap!), but unfortunately Terry has a bad case of red-eye, and she looks a tad possessed.

But no worries, because red-eye removal is a standard photo editing tool, and GIMP’s works beautifully. First click the Ellipse Select tool from the top-left of the toolbox, or from the Tools menu. Then use it to select a region around your subject’s eyes. It doesn’t have to be precise, because GIMP will find the eyes with just a little help from you.

GIMP red-eye preview

Figure 2: GIMP’s red-eye removal tool provides a live preview.

Note: If you’re not familiar with image editing software, you might take a little time to practice using the Ellipse and Rectangle Select tools, because there is a knack to making them select what you want.

OK, back to Terry and Hap. Go to Filters > Enhance > Red-Eye Removal, and you’ll see something like Figure 2. Note than the Red-Eye Removal tool has a slider that lets you adjust the intensity of the color change (threshold). You can preview it before applying it. When it looks right click OK.

Speaking of zoom tools, there is one at the bottom of the main edit window so you can zoom in on your photo and see what you’re doing. If you don’t like the prefab zoom values, you can type in whatever value you want.

Brush and Pencil Sizes

GIMP paint brushes options

Figure 3: GIMP’s adjustable Paintbrush options.

GIMP’s default size for Paintbrushes and the Pencil is 20. You can change this using the up-down arrows in the Brush Size controller, or by typing in a value, or by dragging the blue slider (Figure 3). You also have options for different levels of hardness, patterns, opacity, and a multitude of modes such as dodge, lighten, darken, and many more. All tools offer great option sets.

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