Operation Manual

The Gimp is not installed by default in most Raspberry Pi distributions, so you’ll have to connect your Pi to the Internet and install
it through the package management system (see Chapter 2, “Linux System Administration”, for details). The Gimp takes up quite
a lot of space on the SD card—although not as much as OpenOffice.org—so make sure you have enough free space before
installing it.
To install The Gimp, open a terminal window and type the following:
sudo apt-get install gimp
The Gimp can take a little while to get used to, because its user interface uses three different windows rather than just one. By
default, the window on the left contains the Toolbox; the window on the right displays the Layers, Channels, and Gradients
options; and the middle window displays the image you’re currently editing. If you open more than one image, you’ll get more
than one main window—but still only one each of the Toolbox and the Layers, Channels, and Gradients windows.
By default, The Gimp User Manual is not installed. For the Pi, this is a good thing: The Gimp is a powerful tool, and its user
manual takes up a not-inconsiderable amount of space on the SD card. If you try to access the manual by pressing the F1 key or
choosing Help from the Help menu, you’ll be prompted to read an online, web-based version instead. Click the Read Online
button to open the user manual in your browser.
The Gimp is a very powerful utility, and uses a lot of memory. As a result, it runs relatively slowly on the Raspberry Pi—although
it is definitely usable. Be patient with it, especially if you’re opening large photographs from a digital camera. It may help to
increase the amount of system memory available by changing the start.elf file (see Chapter 6, “Configuring the Raspberry
Pi”, for more details on how this is achieved).
When saving files in The Gimp, you can use a variety of file formats. If you’re planning on coming back to the file and doing more
editing, you should use The Gimp’s default XCF file format. This keeps important metadata intact, uses lossless compression to
maximise image quality and supports images comprised of multiple layers.
If you’re planning on uploading your image to the Internet or otherwise sharing it with others, a more-portable format like JPG or
PNG is recommended. To change the format of the file, choose the Export option from the File menu rather than the Save option
(see Figure 8-4). This allows you to choose the file format from a wide variety of file types.
Figure 8-4: Exporting a file from The Gimp