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Introduction To The GIMP

What is 'The GIMP'?

The GIMP is an advanced image manipulation package that will run on almost every type of computer and in a plethora of languages. It can be used to crop, fix, enhance and mutate your photographs. GIMP shares many features with Photoshop and other similar applications such as Layers, a vast library of filters, lighting & colour adjustments, advanced brush tools and quick-mask.

You can download The GIMP free from www.gimp.org.

What The GIMP Is Not

First and foremost, The GIMP is not Photoshop. While it supports a vast majority of Photoshop's features (and adds many of its own), it is fundamentally different. Photoshop is designed to support both image manipulation and image creation. The GIMP is focused principly on editing existing images. While The GIMP does feature certain things for image creation they are not yet mature and are limited in capability compared to Photoshop. If you were looking for an application suited to designing things from scratch, Inkscape is an excellent way to go.

If you come from a background in Photoshop, The GIMP will feel alien and maybe even difficult and convoluted to use. This is not unusual for a program as complex as The GIMP and I am sure, you will remember similar difficulties getting to know Photoshop. There is a version of The GIMP which has been modified to use similar keyboard short cuts and terminology to Photoshop called 'GIMP Shop', you can find it at www.gimpshop.com.

If you work in the professional printing industry The GIMP may not be suitable for your needs as it does not provide CYMK support without extra plugins.

The GIMP Interface

The GIMP makes use of dozens of different windows and panels to organise all the different tools. By default you are presented with two toolbox windows containing lots of options and buttons. Don't worry if this seems overwhelming or confusing, it's really, really easy!

The Main Toolbox

The toolbox shown on the right contains the main tools you're going to be using while using the gimp. Chances are, when you're just getting started you wont be able to remember what all the icons do, if you forget, hover your mouse over one and it will show a 'tool tip' which explains what the tool does.

Other toolboxes

The GIMP has hundreds of different toolboxes you can add to your screen. Each of them is dedicated to a particular task and many of them are more specialised than others. Generally, it's a good idea to only have the ones you use open to save your computer's resources.

You can stack different toolboxes together in to one window to save space or allow easier organisation. To do this, drag the toolbox by the name (and not the toolbox's title bar). If you drag one toolbox on top of another, it puts them in a tab with that other toolbox. This is ideal for those tools that aren't that frequently used, but often used together. For instance, colour, texture and brush toolboxes could be kept in tabs.

Image Windows

Every image you open in The GIMP is given its own window in which you will find the usual scroll bars on the edges and a 'File Menu' along the top. The file menus on your images are the ones you are going to be using 99% of the time, rather than the menu on the main toolbox.

Also in the image windows you will find a ruler running along the top and left hand side. Along the bottom of the window there are three boxes. The left most box allows you to choose the scale used in your image (by default this is Pixels (1 pixel is one dot on your screen) but you can choose CM, Inches, Points etc.). The next one in shows the current zoom level and allows you to zoom in or out on your image. The final box is a progress bar that will show the progress of any filters or other processes being applied to your image.

Creating, Opening & Saving Images

Creating A Blank Image

To create a new blank image, head to the File menu in the main toolbox and click 'New...'. You will be presented with a dialogue box which asks you for information about the image you wish to create.

You can choose to use a 'Template' to start you off, for instance an A4 page. (Yes, there really is a toilet paper option.) You can enter a custom width & height for your image and select the unit you wish to work in. There are two smaller buttons underneath the Width & height boxes which will select the orientation of your image.

Clicking on the 'Advanced Options' button allows you to select the resolution for your image, weather to use black and white or colour, what colour the initial background should be and add a comment to describe the image.

Once you're done, click OK and your new blank image will open in its own image window.

Opening existing images

As you'd expect, to open an existing image you go to File and choose 'Open...'. From here you can browse to find the image you want to work on. Simply click 'Open' once you've found the image you want to work with and it will appear in its own image window.

You can also use the 'Open Location' option, found in the File menu to open images directly from the internet. To do this, simply copy the URL of an image you'd like to work with into the box and click 'Open'.

Finally, on supported systems, you can simply drag and drop images onto the main toolbox of The GIMP and it will be opened. This includes images from the internet.

Saving images

GIMP has three different ways to save your work and via each method, you can save your image in a multitude of formats with fine-grained control over the options.

• 'Save...' If you have not saved your image yet, this option presents the save dialogue for you to enter a file name & file type. For subsequent uses of save, the image is over-written on the disk and no prompt is shown.

• 'Save as...' This displays a prompt where you can enter file name and file type information. When you click save, the current image is saved to disk and becomes the file you are editing. (e.g. If you were editing cat.png and used Save as to save it as tiddles.png, you would now be editing the file tiddles.png, not cat.png.)

• 'Save a copy...' This displays a prompt where you can enter filename and file type information. This option simply saves a copy of the image in its present state under the name you specify but does not become the file you are editing. (e.g. If you are editing cat.png and you Save a copy as tiddles.png, the image will be saved to tiddles.png however you will still be editing cat.png.)

  This function is particularly useful for web development as you can quickly save a low-quality version of a file for your website while keeping the high-quality version open in The GIMP.

Once you've chosen an appropriate save method, you will need to enter the appropriate details into the save dialogue box. Enter a name and location and make sure to choose an appropriate format type. By default The GIMP saves in its own format (which preserves a lot of GIMP-specific features such as layers) but you can choose from many others.

After you've chosen you file name & type, you may be presented with a second option window. What is in this window depends on the format you choose and it offers advanced tweaks for that specific file format, for instance quality and compression rates. You can usually safely ignore this but web developers will want to pay attention to what it says.

Doing something useful

Unfortunately, it goes beyond the scope of this article to start to do something useful, instead I suggest you have a fiddle around and see what you can do. I suggest a good look at the Filters menu for some quick and easy fun!

Have a look at some of the other GIMP tutorials to get started.