[Courses] [gimp] Lesson 0: Welcome! Get Familiar with the GIMP

[Akkana Peck]

Welcome to "GIMP for beginners"!

Lesson 0: Get familiar with the GIMP.

What is the GIMP?  The name stands for "the GNU Image Manipulation
Program", and image manipulation is the GIMP's primary purpose.

This course is aimed at people with an interest in image processing,
but not much experience with actual image editing.  But anyone
is welcome!  Feel free to ask questions, or jump in with discussion
or corrections.  And if you know an easier way to do something I
talked about, don't hesitate to point it out!

If you have a question like "How would I accomplish this thing
that I can do in [proprietary app]?", feel free to ask, but keep
in mind that not everyone may be familiar with the app. 
So describe what the function does, or post "before" and "after"
images: don't just give the name of the function.

For this course, you will need:
- Access to a computer with GIMP installed.

  I will generally be using GIMP 2.2, the current version,
  for the examples.  But since I realize a lot of people are
  using earlier versions, I'll try to give an idea where to look
  for things which might have moved around.

  If possible, try to use at least GIMP 2.0, since the user interface
  changed quite a bit from 1.2.  But if you need to use 1.2, and can't
  find something, feel free to ask about it!

- Electricity.

- Access to some digital images: from a digital camera,
  scans, or images downloaded from the web.

- Access to the internet, and willingness to share some of
  your creations.  Each lesson will have "homework", where
  you're encouraged to produce an image using some of the
  techniques discussed.  Please participate!  Sharing images
  is fun, and I think students will have fun with it too.
  If nobody shares their images, I'll probably get demotivated
  and quit writing lessons.  Fair warning. :-)

  If you have a web site to post your own images, that's ideal.
  If you don't have any web space, there are lots of places that
  offer free hosting of photos (the hook is usually that they hope
  you'll order prints from them).  Try googling for something like:
    free photo "web site"

Enough background ... let's get started!  Start up the GIMP on your
own machine, either from your system menus, by double-clicking the
gimp icon, or by running "gimp" from the commandline.  (You can also
run "gimp file1.jpg file2.png ..." if you have a specific set of
images to edit.)

If you run gimp from the commandline, you may want to put an ampersand
("&") at the end of the line, so that gimp will run in the background,
and you will be able to use your terminal for other things while gimp
is running.  Something like:
  gimp file1.jpg file2.png &

Depending on version, GIMP will usually pop up several windows.
Let's go through the important ones:

The Toolbox Window

This is the GIMP's main window: the titlebar just says "The GIMP.
It has a very simple menubar, which you can use to call up functions
that aren't specific to any particular image.  Let's go over the three
menus:

The toolbox File menu contains file operations such as Open a new image.
It also has an Open Recent submenu, which you can use as a shortcut
to revisit images which you've edited recently.  This can be a real
timesaver versus poking through the filesystem looking for where you
stored the image.  The File menu also includes Preferences (which I'll
discuss in a later lesson), a Dialogs submenu which allows you to
bring up or shoo away some of the GIMP's other dialogs, and Quit.

The toolbox Xtns menu contains various scripts to do fun things.
I'll discuss some of them in a later lesson; meanwhile, you might
enjoy exploring the Python-Fu and Script-Fu submenus.  There are
tons of cool scripts in there.

The Help menu brings up the GIMP's help system.  The help system for
GIMP 2.0 is based on gnome help, and unfortunately a lot of systems
don't have all the necessary pieces installed.  Try it, but if it
doesn't work, don't panic.  There's lots of GIMP help available
online, and if you're in this course, then you have a place to ask
questions about anything you're having problems with!

Below the menubar, most of the GIMP toolbox is taken up by the "tool
palette": small icons representing various GIMP tools.  We'll talk about
those tools in future courses.  For now, if you move the mouse over a
tool and stop there, you'll get a tooltip telling you what tool the
icon represents.  Feel free to play around with changing tools and
experiment with what some of the tools do.

Below the tool palette is a color selector, on the left, showing
foreground and background color; and on the right, an area showing the
currently selected brush, fill pattern, and gradient.
These are used by the text tool and various drawing and painting
tools; we'll be talking about them in future lessons.  For now,
clicking on them will bring up a dialog allowing you to change them.

If you see anything else below the color/brush/pattern/gradient
selectors, it probably means you have another dialog docked at the
bottom of the toolbox window.  Since this varies by user, anything
which might be docked there will be discussed later.

The Layers Window

Another window which GIMP will show, in addition to the toolbox
window, is the Layers, Channels, and Paths window.  Most beginners
immediately close this window when they start GIMP; but in this
course, we'll be using it, so I encourage you to leave it open.

Image Windows

Each image GIMP opens will have its own window.  In GIMP 2.0 and 2.2,
these windows have their own menubars across the top (this is
configurable in Preferences); in 1.2, they don't.  But in any version
of GIMP, whether or not there's a menubar, you can always get to the
image window menus by right-clicking inside the image window.

Other Windows

Depending on your GIMP version, you may see other windows, such as
Tool Options, Brushes, or Devices.  We'll talk about those later,
but for now, you don't need them.

This concludes the (rather long) intial lesson.  Your only homework
for this lesson is to look through the gimp menus, mouse over the
tools in the toolbox to see their tooltips, and generally get familiar
with how the app looks.  Try opening an image, or maybe running some
of the scripts in the Xtns menu.  Have fun!

Next lesson: Basic Photo Editing.  Stuff you'll want if you upload
pictures from your camera and want to crop and resize them for the web.