GNU Image Manipulation Program (GIMP)

Tutorial

Source: Quackit.com Compiled by: Sabah State Computer Services Department (JPKN)

April 2010

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TABLE OF CONTENTS

About Gimp ................................................................................................................3

Download The Gimp ...................................................................................................5

Getting Started ...........................................................................................................6

Creating Your First Image...........................................................................................7

Saving Images...........................................................................................................13

Supported Image Formats........................................................................................16

Selection Tools..........................................................................................................19

Adding Color..............................................................................................................23

Resizing Images .......................................................................................................25

About Layers.............................................................................................................27

Examples of Layers...................................................................................................27

Creating Layers.........................................................................................................30

Gimp Filters...............................................................................................................34

Path Tools..................................................................................................................37

Drawing Paths...........................................................................................................38

Animated GIFs..........................................................................................................42

Summary...................................................................................................................51

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About GIMPWhat Is The GIMP?GIMP stands for GNU Image Manipulation Program (formerly General Image Manipulation Program). GIMP is a free graphics editing package. It is typically used to do things like:

• Touch up photos • Resize graphics • Scan photos • Create logos • Create animated GIFs • Export graphics to web format • ...and much more

It's basically a free alternative to Adobe Photoshop. Most of the things you can do in Photoshop you can do in GIMP.

What Does The GIMP Look Like?Here's what the GIMP looks like in normal editing view. There are many other dialogs that you can bring up depending on what your task is, but this is the basic view. We will be looking at some of the other dialogs later in the tutorial.

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Features & CapabilitiesGIMP is loaded with features. If you've ever worked with commerical programs like Photoshop, you'll be familiar with many of GIMP's features.Below are some of the main features of GIMP. Don't worry if you've never heard of these features - we'll be covering many of them in this tutorial.

• Painting tools including: • Brushes • Pencil • Airbrush • Cloning tool • ...and more

• Transformation tools including: • Rotate • Scale • Shear • Flip

• Selection tools, including: • Rectangle • Ellipse • Free • Fuzzy • Bezier • Intelligent scissors

• Layers and channels • Advanced scripting capabilities • Full Alpha channel support for working with transparency • Multiple undo/redo (limited only by disk space) • Tile-based memory management, so image size is limited only by available disk

space • Sub-pixel sampling for all paint tools for high-quality anti-aliasing • A procedural database for calling internal GIMP functions from external programs,

such as Script-Fu • Support for a wide range of file formats, including GIF, JPEG, PNG, XPM, TIFF,

TGA, MPEG, PS, PDF, PCX, BMP and many others • Plug-ins that allow for the easy addition of new file formats and new effect filters.

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Download The GIMPYou can download GIMP for free from the GIMP website – www.gimp.org. Feel free to do this now, or bookmark this page and come back to it.

Known PlatformsGIMP is the most widely supported image manipulation available. GIMP has been known to work on the following platforms:

• GNU/Linux • Apple Mac OS X • Microsoft Windows • OpenBSD • NetBSD • FreeBSD • FreeBSD • Solaris • SunOS • AIX • HP-UX • Tru64 • Digital UNIX • OSF/1 • IRIX • OS/2 • BeOS

Furthermore, GIMP can easily be ported to other platforms due to the availability of its source code.

Installing GIMPIf you use Windows, installing GIMP is usually just a matter of clicking on the installation file that you downloaded. Clicking on the file will launch an installation wizard. You can use the default options or change them as required.If you use Mac OS X, you will need to install X11 first. You can get this from your installation CD. Once X11 is installed, you can install GIMP just as you would with any other program.If you use a Unix based system, the Gimp Toolkit (GTK+) and other libraries that must be installed first. If/once they are, you can compile as a normal user using: ./configure && make and then as root make install. For more info on installing on Unix systems, check out the official GIMP install help.

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Getting StartedOnce you've downloaded and installed the GIMP, you are ready to start manipulating some images!Open GIMP the same way you would open any other program. For example in Windows, you can either double click on an icon on the desktop or go Start > All Programs > GIMP > GIMP 2.

GIMP's Main ToolboxWhen you open the GIMP, the only thing that appears is a toolbox. The toolbox looks something like this:

This toolbox is the centerpiece of the GIMP. Most of the time, you'll be using options from this toolbox.The main toolbox provides shortcuts to the most commonly used tools in GIMP. The top row includes selection tools - tools for selecting areas of an image. The toolbox also provides tools for rotating an image, scaling an image, adding text, adding color, and more.Hovering the mouse over an icon will usually bring up a "tooltip" that explains what the tool is or what you can do with it. Also, in many cases you can press the F1 key to get help about the tool that you're hovering over.

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Creating Your First ImageNow that we've started GIMP, we have a choice of opening an existing image or creating our own one. We'll create our own image for now. We'll create our own little smiley face. Like this:

Open a New (Blank) ImageTo create an image, we first need to open a blank image, or blank canvas. Here's how to do that:

1. Go to File > New...:

2. Choose the size you'd like your image to be. Feel free to select a template from the

drop down menu. You can also expand the Advanced Options menu for more options. For the purposes of this tutorial, simply type in the width and height as shown in the following screenshot:

72 dpi (as shown in the above screenshot) is perfect for displaying your image on a computer screen (such as on a website). It is also sufficient for printing on a home

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printer. If you intend to use your image for commercial printing purposes, you should increase this value. Commercial printers usually request high resolution images at between 240 dpi and 300 dpi. Beware that by using high resolution images, the file size will become much larger and it will take longer to download/email etc. To change the dpi value, click on "Advanced Options" and change the resolution.

3. Click OK You will now see a blank, untitled image. It looks similar to say, a blank word processing document. Well, our blank image may look like a word processing document, but it doesn't act like one!With our blank image, we have the ability to manipulate every single pixel. We can type text, paste photos, create a drawing, and much more. But more importantly, we have total control over where everything goes.Anyway, let's create a basic picture for now.

Image CompositionOur smiley face image consists of a bunch of circles, a straight line, and a curved line.To do this, we use a combination of the following tools:

• The Ellipse selection tool • The Paintbrush tool • The Pencil tool.

Here's how we do it.

The Face OutlineFirst, let's create the face outline. It's basically a circle, so we can use the Ellipse selection tool.

1. Select the Ellipse selection tool. To do ths, click the Ellipse icon from the main toolbar. The Ellipse icon looks like this:

2. Now click and drag within the image area (also known as the "Canvas"). This will

create a circular selection area, highlighted by an animated dotted line (also known as "marching ants"). For best results, start somewhere near the top-left corner, and release near the bottom-right corner. Your selection should look something like this:

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You can see by the above screenshot that the image is being displayed at its full size (the text "100%" is being displayed under the image). You can zoom in and out by clicking the down-arrow. Alternatively, you can select View > Zoom.

3. Now we will create a thick black line around our selection. To do this, select Edit > Stroke Selection...

4. A dialog box will pop up. Set the stroke width to 6 px and ensure that Line Style is

set to "Solid".

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5. Click OK You should now see a black line in the shape of your selection. Your image should look something like this:

You may notice that the "marching ants" remain on your selection. This is because the selection still exists (in case you need to do anything else with your selection). Before you continue to the next step, you should remove the selection. To remove the selection, select Select > None (or keyboard shortcut: Shift+Ctrl+A).Your line may be a different color. This will depend on what color is selected as the foreground color on your main toolbox. If white is selected, you won't see your stroke (because the background is also white). If this is the case, you will need to change the color. You can do this by clicking on the foreground color and changing it. The foreground color is the black part on the left side of the color area. Here's a screenshot of the color area:

If you have trouble changing the foreground color, there's a more detailed explanation on our lesson for adding color.

The Eyes and NoseWe will now create the eyes and nose. We will do this with the paintbrush tool.

1. Select the Paintbrush tool. To do this, click the Paintbrush icon on the main toolbox. The paintbox icon looks like this:

2. Now make two dots (where the eyes should be). To do this, simply click on the

image where you want the eyes to be. If you make a mistake, you can always "Undo" (Ctrl+Z) then try again.

3. Now draw a line where the nose should be. You do this by clicking and dragging. Again, if you make a mistake, Ctrl+Z will undo it.

At this stage, your image should look something like this:

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Now for the mouth.

The MouthFor the mouth, we will use a more advanced tool. We will use the Path tool. This tool allows us to create smooth curves. You may be wondering why we don't just use the Paintbrush tool for the mouth? Well, feel free go ahead and try! You'll find that it's extremely difficult getting the curved line to look nice and even while using the paintbrush tool.The Path tool on the other hand, allows you to create a nice, smooth curve.I should mention that the Path tool can take a bit of getting used to. It's not as easy to use as the Paintbrush tool. But I recommend practicing with the Path tool as it will give you much more control over your image compositions.

1. Select the Path tool. It's the one that looks like this:

2. Click where the right corner of the mouth should be. 3. Now click and drag, starting from where the left corner of the mouth should be. You

need to drag to the right, and slightly up. You will see a path forming in the shape of the mouth. The path forms between your two anchor points. You will also see some levers with handles that enable you to change the shape of the path. Move the mouse around until you're happy with the shape. Then you can release the mouse. Here's what it should look like so far:

4. Now for the stroke. Select Select > Stroke

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5. When the dialog box pops up, click OK. This is the same dialog box that popped up

before when we created the stroke around the face. For now, we'll leave the stroke at the same setting as before (6 pixels and solid).

Your face is now complete. It should look something like this:

When you create a path, it is automatically saved so that you can use it again later. You can view your saved path by opening the Path dialog box (Dialogs > Paths).Don't worry if you don't quite understand paths right now, we'll be covering them in more detail later.

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Saving ImagesSo you've created your first image in GIMP. Now what? You should save your image (before something happens and you lose your 2 minutes of hard work!)When saving images, you need to decide which format you want to save the image in. Of course, there's nothing stopping you saving multiple copies of the image, each in a different format. In fact, I recommend keeping multiple copies of your image - especially if you are doing a lot of work on it.In any case, you still need to understand which is the best format to use.

Saving Your ImageIn GIMP, the way you specify an image's format is to save it with the applicable extension.For now, we'll save our image in XCF format (GIMP's native format). It's a good idea to have at least one copy of your image in native GIMP format. You might even create multiple copies, each at different stages of modification.

1. Select File > Save As...

2. Once the dialog box pops up, enter the image name ensuring you use a .XCF

extension. Alternatively, you can expand the "Select File Type" node to select your preferred file type. You can also expand the "Browse for other folders" node to

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choose which folder to save the file into. 3. Click Save

Depending on the file format you use, you may see another dialog box where you can enter values specific to the file format. In this case, you can either use the default values or adjust settings as required.

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About .XCF ExtensionGIMP's native format uses a .XCF extension. This is the best format to use if you intend to modify the image in the future. By saving your file with a .XCF extension, you ensure that all image data (such as layers, channels, paths etc) is saved exactly how you created it. When you open it up again, you can continue from where you left off.Note that only GIMP recognizes the XCF format - you will only be able to open XCF files with GIMP.

Saving For WebThere are two very important things to remember when creating graphics for the web:

• Keep the file size down • Use the correct format

File SizeGraphics have the potential to be really big. I mean really big. The problem is that, if you don't know what you're doing, you might not notice how big the file size is. The graphic may look small on the screen but, if it's using a high resolution, its file size could be much larger than you need it to be. This could result in the image taking too long to download for your users to view.Check that the image is using a resolution of 72 dpi. Assuming that it is 72 dpi, when you view the image at 100% zoom, it should be the correct size.Also check that you're using the correct color mode (i.e. RGB, grayscale). Color images should be RGB. Black and white should be grayscale. To check this, go to Image > Mode. The current mode will be grayed out.

Correct FormatIf you intend to use your image on a website or blog, you will need to save it in a format that web browsers recognize. The most common file formats to use for the web are GIF, JPEG, and PNG.In general, JPEGs are best for complex images with lots of colors (such as photos). GIFs on the other hand, are better for images with flat colors (such as cartoon illustrations, logos etc). For more information on the difference between GIFs and JPEGs, see GIF vs JPEG.

Other Supported FormatsGIMP supports many different file formats. You can see these formats whenever you save a file and expand "Select File Type" (as in the screenshot above).

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Supported File Format

Popular File FormatsThese file formats are well known and their usage is quite widespread.

File Format

Extension(s) Description

XCF

.xcf/

.xcf.gz/.gz/.xcfgz/

.xcf.bz2/.bz2/.xcfbz2/ .gbr/.gih/.pat

GIMP's native format which will preserve all image data, including layer, the current selection, channels, transparency, paths and guides. Note that it doesn't save undo history.

XCF images take up a lot of disk space, and are not supported by most image viewers, which is why XCF is more suitable for saving images for future editing (rather than image exchange).

If you must exchange a XCF file, you can use the compress option, which uses either gzip (using xcf.gz/gz/xcfgz extension) or bzip2 (using xcf.bz2/bz2/xcfbz2 extension) compression.

Other GIMP's native format includes GIMP Brush (.gbr), GIMP Animated Brush (.gih), and GIMP Pattern (.pat).

BMP .bmp/.dibBitmap is an uncompressed image format, which is the internal image format for Windows and OS/2 Graphic Subsystem.

GIF .gif

Graphic Interchange Format is often used for screenshots and computer graphics. It is lossless if the image has under 256 color or otherwise it become lossy.

The GIF format allows transparent mask, which means a pixel can only be fully transparent or fully opaque, and not partially transparent.

HTML .htm/.html

Hypertext Markup Language. GIMP will save an HTML page with the image represented by an HTML table. Each table cell represents a different pixel in the image. Hexadecimal colors are used in order to apply colors to each cell.

ICO .ico Icon Image File Format is Windows' image format for icons.JPEG .jpg/.jpeg/.jpe Joint Photographic Experts Group is typically used for

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File Format

Extension(s) Description

photographs. JPEG uses lossy compression that results in a loss of detail, commonly called artifacts. The artifacts are usually most noticeable on images that have sharp edges, while less noticeable on photographs, which have many smooth gradients.

PNG .pngPortable Network Graphic is often used for screenshots and computer graphics. It uses lossless compression. It allows full alpha transparency.

PNM.pnm/.ppm/.pbm/ .pgm/.pam

Portable Pixmap. PNM (Portable Any Map, a shorthand for ppm, pbm, and pgm format), PPM (Portable Pixel Map), .pbm (Portable Bit Map), .pgm (Portable Gray Map) and .pam (Portable Arbitrary Map).

PS and EPS .ps/.eps Postscript Document and Encapsulated Postscript

PSD .psd Photoshop Document, the native format of another popular graphic editing software, Adobe Photoshop.

TGA .tga Truevision Graphics Adapter, Targa's native image format.TIFF .tif/.tiff Tagged Image File FormatXBM .xbm X Bitmap 2-bit, Monochrome Bitmap for X Window SystemXPM .xpm X Pixelmap Color Bitmap for X Window System

Less-Popular File FormatsThe GIMP also supports the following, less popular, file formats.

Extension(s) Description.pix/.matte/.mask/.alpha/.als Alias/Wafefront Pix Image

.fli/.flc Autodesk FLIC Animation

.c/.h C/C Header Sourcefile Format

.dcm/.dicom Digital Imaging and Communications in Medicine Image

.fit/.fits Flexible Image Transport System

.cel KISS Cel

.sgi/.rgb/.bw/.icon Silicon Graphic IRIS Image

.im1/.im8/.im24/im32/.ras/.rs SUN Rasterfile Image

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Extension(s) Description.pcx/.pcc ZSoft PCX Image.xwd X Windows Dump

Limted SupportThe GIMP can read, but not write, files in the following formats.

Extension(s) Description.g3 G3 Fax Image.wmf/.apm Microsoft WMF File.psp/.tub Paintshop Pro.pdf Printable Document File.svg Scalable Vector Graphic

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Selection ToolsSelection tools are an essential part of GIMP. You'll find that many tasks you perform in GIMP will involve a selection tool.

What Do Selection Tools Do?Selection tools enable you to select exactly which part of the image you want to work with.Once you make a selection, anything you do will apply only to that area (the area that the selection covers). This is essential when building shapes (like the smiley face from our previous lesson). It is also essential when selecting objects from photos.When you make a selection, the selection is made against the current layer. We'll cover layers soon but, basically layers allow you to break your image up into separate parts - all stacked upon each other.I highly recommend becoming familiar with the various selection tools. There are different selection tools for different situations. Choosing the right tool for the job can save you a lot of time.ExampleTake the following photo for example.

In this photo, most of the hill has been selected. You can tell because "Marching Ants" follow the edge of the hill. The lighthouse, the ocean, and the sky are not selected.This selection was made using the Fuzzy Select Tool - otherwise known as the Magic Wand. The Magic Wand works based on color similarity. It selects parts of the image that are similar in color to the area you click in. So now that the hill has been selected, our work on the image will only apply to the hill. For example, if we grabbed the Brush tool and drew a big line through our image, it would only affect the part where the selection is. Perhaps a more realistic task would be to adjust the colors or brightness of the hill. Another thing we could do is copy the hill and paste it into another image. We could also add the lighthouse to our selection.

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Creating A SelectionThe way you create a selection will depend on the selection tool that you use. Some require you to click and drag. Some require you to click various parts of your image in order to indicate the selection area. Others simply require a single click. Most are reasonably intuitive.The table further down in this lesson outlines each tool and how to use it.

"Deselecting" A SelectionOnce you've made a selection, it will usually stay there, waiting for you to do something with it. If you decide that you don't need the selection, you can remove it. You can remove/deselect an active selection by going to Select > None, or using the keyboard shortcut of Shift+Cntrl+A.Another way of removing an active selection is by clicking outside of the selection (while still having a selection tool selected).

Modifying A SelectionYou can modify an active selection by holding the Shift key down while modifying the selection. If you don't hold this key down, you will wipe your existing selection and create a new one.You can also add to existing selections by using a saved path or channel. More on saved paths and channels below.

Saving A SelectionSelections are generally temporary - once you "deselect" a selection it's gone forever. Once you deselect a selection, you will need to make your selection again.Having said this, if you think you might need to use the selection again in the future, you can always save it as a path or channel.To save as a path, use the Save to Path option. Once it has been saved as a path, you can reload the selection from within the Path dialog box by right clicking on the path and selecting Path to Selection).To save your selection as a Channel, use the Save to Channel option. You can reload the selection from within the Channel dialog box by right clicking on the channel and selecting Channel to Selection.

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The Selection ToolsLet's have a quick look at the various selection tools, what they do, and how to use them.

Icon Tool DescriptionRectangle Selection Tool

Selects an area in the shape of a rectangle. Simply click and drag to create a rectangular selection. The selection is made once you release the mouse.

Ellipse Selection Tool

Selects an area in the shape of an ellipse (a circular shape). Simply click and drag to create an elliptical selection. The selection is made once you release the mouse.

Lasso Selection Tool

Allows you to draw a selection free-hand with your mouse or other pointer. When you release the mouse button, the selection is closed by connecting the current pointer location to the start location with a straight line. You can go outside the edge of the image display and come back in if you want to.

Fuzzy Select Tool (Magic Wand)

Enables you to make a selection, based on contiguous areas of a similar color range. The color range is determined by the point at which you click on and the value of the Threshold (within the Tool Options dialog).

Select By Color Tool

Allows you to select areas of an image with a similar color range. The difference between this tool and the Fuzzy Select tool, is that the fuzzy select tool selects contiguous pixels - those that are next to, or close to, each other. The Select By Color Tool, on the other hand, selects all pixels within the color range, regardless of their location on the image.

Intelligent Sissors

This tool is useful when you are trying to select a region defined by strong color-changes at the edges. To use the Intelligent Scissors, you click to create a set of "control nodes", also referred to as anchors or control points, at the edges of the region you are trying to select. The tool produces a continuous curve passing through these control nodes, following any high-contrast edges it can find.

Note that this tool doesn't always produce a nice, smooth path. Many experienced GIMP users tend to use the Path tool instead.

Path Tool

Technically, this tool is not a selection tool, however it creates paths - which can be turned into selections. This tool allows you to draw around the edge of any object on your image. More importantly, it provides you much more control than the other selection tools when working with complex shapes. Similar to the Intelligent Sissors, the Path tool results in control points that you can move around as required.

Foreground The Foreground Select tool was released in GIMP version 2.4.

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Icon Tool Description

Select

Using this tool is done in two steps. First, you make selection which contains the entire object. Then you paint over the selected area with a brush, not crossing object’s border. Release mouse button when you’re done and look to see if there are dark blue spots on your objects. If there are some, paint over them with a brush again and release to refine the selection. When there are no more blue areas inside the object, press Enter and your object will be selected.

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Adding ColorAdding color to an image is a easy as a couple of clicks. Changing the color is just as easy.Before you add color to your image, you need to select a color. You do this using the color area in the toolbox.The color area shows two colors: the foreground and background colors.

Selecting a New ColorTo select a new color, click on either the foreground color or the background color from the color area then select the new color from the color palette.For example, to select a new foreground color:

1. Click on the foreground color (in the color area) 2. You will now see a color picker. You can click in any of the color areas to select a

color. Having said this, the idea is to use the large square at the left. This is the Gimp Color Selector. In our screenshot, the Gimp Color Selector is filled with reds that fade to black and white. If we wanted to select say, green, we would first click the color strip to the right (we would click somewhere in the green area of the strip). Doing this would automatically fill the Gimp Color Selector with green. We could then click anywhere in this large square to refine our selection of green.

You can also use the tabs at the top of the large square to change colors. These represent different modes of color selection. The printer icon represents CMYK, the triangle is for selecting color by hue, and the brush icon selects watercolor.When using watercolor mode to choose your colors, you can click in the large square multiple times. Each time you click, you add more color to your selection.

3. Once you're happy with your color selection, click OK

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The Eyedropper ToolIf you want to select a color that's already on your image, you can use the eyedropper tool (from the main toolbox). With the eyedropper tool selected, simply click anywhere in the image. This will set the foreground color to the same as the area of the image you just clicked on.The eyedropper icon looks like this:

Applying Your ColorNow that you have selected a color, you can apply it to your image.There are different ways of applying color to your image. The quickest way is to use the paintbucket.

Option 1: The PaintbucketThe paintbucket allows you to apply color to a large area of your image. To apply color using the paintbucket:

1. Click the paintbucket icon in the toolbox: 2. Now click on your image in the area you wish to apply the color to. In this example, I

clicked somewhere within the face:

Before: After:

Option 2: Drawing/Paint ToolsWhenever you use a drawing or paint tool, the color is automatically set at the current foreground color (i.e. the selected color from the color area). To change the color of the drawing/paint tool, simply select a new color as shown above.In the example below, I've made my little face blush:

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I did this using the airbrush tool (from the main toolbox) and selecting a darker shade of red. The airbrush icon looks like this:

Resizing ImagesResizing an image is one of the most common uses of image editing software. This lesson demonstrates how to resize an image using GIMP.

Resizing an Image using GIMPYou use the "Scale Image" feature to resize images in GIMP.Here, we'll resize the little face that we created in the last lesson. So, to refresh our memory, here's what that image looks like:

We'll now use the "Scale Image" feature to resize the image.

1. From the "Image" menu, click "Scale Image":

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2. You should now see the dialog box for changing the size of your image. You can select an exact size (eg. pixels), or you can choose a percentage to scale to. In this example, I have chosen to resize the image to 75x75 pixels.The chain icon constrains the proportions of the image - it forces height and width to stay proportional to each other. Therefore, if you scale the width, the height will automatically be scaled too (otherwise the image would end up looking warped). If you don't want proportions to be constrained, you can break the chain by clicking on it.

3. Once you're happy with your adjustments, click "OK".

That's all there is to resizing an image using the GIMP. You should now see the resized image:

. Resizing images works best when making the image smaller. If you try to make the image larger, the image will lose quality. If you resize it too large, the image will become quite visibly pixelated.When resizing images, it's a good idea to keep a copy of the image in its original size. That way you won't lose quality if you ever need to revert to the original size.

ThumbnailsA common reason for resizing images is to display a smaller image first, which when clicked on, will display the image at full size. The smaller image is often referred to as a "thumbnail".When creating thumbnails, don't be tempted to resize the same (larger) image just by using HTML. It is much better to resize an image in an editor (as above) than to rely solely on HTML. Resizing an image in HTML doesn't actually resize the image - it just forces the image to display at a smaller size. This wastes bandwidth (the image still has the larger filesize), and it could also diminish the quality of the displayed image.

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Yes, it's true that you will need to change the HTML, but as long as you resize the actual image itself also.

About LayersLayers are an important part of creating images in GIMP. If you're familiar with Adobe Photoshop, you'll know what I mean. Layers provide you with the ability to separate different parts of your image, so that you can manipulate each part separately to the rest of your image.

The Benefits of LayersLayers give you more control and flexibility over your image compositions.Layers enable you to stack images on top of other images - all within the same image. Therefore, you can have multiple layers of images, stacked on top of each other. But most importantly, each layer can be transparent or semi-transparent as required. Therefore, despite having layers on top of others, you are still able to see the other layers beneath them.If we didn't have layers, our life would be so much more difficult. Layers enable you to add and remove parts to your image without affecting the rest of the image. They help you experiment with different effects. If you find that something doesn't work, you can just delete the layer (or hide it) - the rest of the image is still intact.

Example of LayersLet's take the following image:

This image contains three layers: one for the background, one for the oval shape, and one for the text.Here's what the image looks like when editing it in GIMP. In this screenshot, I have the layers dialog box open. Notice the three layers in the dialog box:

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If we hide the middle layer, we get this:

If we hide the top layer, we get this:

If we hide both the top and middle layers, we'd get a blank white image (because the background is white).One of the great things about layers is that you can treat each layer differently. For example, on one layer, you could change the transparency level, on another layer, you could paste an image, and on another, you could write text. The possibilities are endless. And the end result, is a more interesting image.You can see why layers can be a powerful tool in creating image compositions. The above example uses a very basic image, but just imagine the possibilities. Actually, this is still quite a simple image. However, it contains more elements that can be separated. Therefore, we can create more layers in order to give us more flexibility.

Example ImageLet's look at the following image:

I created this little character using 12 layers. It could have been made with as little as one layer, but I found that 12 layers gives me much more control and flexibility.

Breakdown Of LayersYou may be thinking "12 layers! How do you get 12 layers from a simple image like that?"Well, the following screenshot should give you some idea of what elements are separated into different layers.

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You can see that virtually every element has been allocated its own layer. Even the eyes take up four layers; one for the outline, one for the pupils, one for the eyebrows, and one for the shading.You might think that this is a bit of overkill. After all, eyes are eyes aren't they? They won't be changing anytime soon?Well, think again!

Modifying Our Image - Reaping The Benefit Of Layers!Lets say I decide that I don't like the shading on this little character. No problem, I can simply hide the layers that provide the shading.And, let's say our little character sees something to his left. What is he going to do?

It took me less than a minute to make those modifications and export it to a GIF. I simply hid the layers for the shading, then moved the layer with the pupils a little to the right. Once I was done, I could move it back.Now if our little character sees something to his right, we'll know what to do!

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Creating Layers

Displaying The Layers Dialog BoxBefore you start working with layers, it's best to open up the Layers dialog box.You can display the Layers dialog box by selecting Dialogs > Layers from the image you're working with.Here's what the Layers dialog box looks like:

In the above example, we only have one layer - the background layer. At least one layer is always present - when you create a new image, it already has one layer. Therefore, if you don't create any new layers you will always have at least one layer.

Creating a New LayerWhenever I create an image, usually the first thing I do is create a new layer. If I add anything to the image, I will often create another layer. I can always combine layers later if I so wish.To create a new layer:

1. From the Layers dialog box (above), click the "New Layer" icon on the bottom left of the box. Here's what this icon looks like:

2. A "New Layer" dialog will open. Give your layer a name, and make any other

adjustments as required. For now, we'll leave everything else as is:

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3. Click OK

Your new layer will appear above the background layer. Like this:

You can rename the layer by double-clicking on it. Alternatively, you can right-click, then select Edit Layer Attributes. You can also use the "Duplicate Layer" feature to create a copy of the current layer. To do this, use the "Duplicate Layer" icon located along from the "New Layer" icon. Here's what the Duplicate Layer icon looks like:

What To Do With The Layer?So, now that you've created your new layer, spend a couple of minutes trying out some layer-related tasks.For example, try this:

1. Add a second layer 2. Paint something on each layer using a different color (remember, you can use the

Layers dialog to switch between layers) 3. Change the Opacity level on the top layer (using the Opacity slider on the Layers

dialog). See what that does to your image. 4. Click and drag the top layer below the other layer. See what that does to your

image.

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Layers And TextWhen you add text to your image using the Text tool, you automatically create a new layer. If you add more text later, that will create a new layer too. This is quite handy because your text is automatically separated from the rest of your image - which as you know, provides you with more control over your image.

Adding text to an image is a common task. It's highly likely that you'll find yourself working with text on a regular basis. Therefore, it is important that you understand how text works in GIMP.Adding text with GIMP is a bit different to adding text with say, a word processing application (such as MS Word or WordPerfect).At first, you might find GIMP a bit "clunky" when working with text. Hold in there though. Once you get the hang of it, you will find that GIMP provides you with an enormous range of options for how your text is presented.

How To Add TextTo add text in GIMP, open a new image (File > New) and then do the following:

1. Select the Text tool. To do this, click the Text tool icon from the main toolbox:

2. Click within the image, roughly where you would like the text to appear. 3. The GIMP Text Editor will pop up. Enter your text into the text editor. As you type,

the image will be updated with your text using the current style. Don't worry if it's not in the style you want, you can change the style later on. At this stage, it should look something like this:

4. Once you've written your text, feel free to close the GIMP Text Editor. You can open

it again later if you need to change anything.

Text And LayersWhen you add text in GIMP, a new layer is added automatically. When you view your Layers dialog, you will see a new layer containing the text you just created.

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This is quite handy, as it gives you the ability to manipulate the text without affecting other parts of the image. As mentioned previously, this is one of the main benefits of layers.

Manipulating The TextOnce you've added your text, you can then manipulate it as required. For example, you can change the font family, change the size, color, etc. You can also do things like, apply special effects/filters against your text, transform your text using transformation tools, etc.

Changing The FontNow that you've entered your text, you may be wondering how to do something simple, such as change the font.This is where the Tool Options dialog comes in handy.To change the font (as well as other properties):

1. Make sure you still have the Text tool selected (on the main toolbox), and that the correct layer is currently selected/highlighted. If these aren't selected, select them now.

2. Open the Tool Options dialog. You do this by selecting Dialogs > Tool Options. The Tool Options dialog looks like this:

3. Change the font as required. To do this, click on the "Aa" button and select a font

from the list. As you can see, there are other properties that you can change here. A common mistake by beginners is that they forget to do step 1. In other words:

• They forget to select the correct layer before changing the text properties; and/or • They forget to select the Text tool (from the main toolbox). This results in the Tool

Options dialog not displaying the font properties (it presents properties for a different tool - whichever tool is selected)

So, if you have trouble getting the text properties to display, this could be the reason. So, don't forget to do step 1.

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Gimp FiltersIn this lesson, we'll take a look at GIMP's filters. Filters can provide special effects for your image. Again, Photoshop users will be familiar with how powerful Photoshop filters can be. The same applies to GIMP filters.

What Is A Filter?A filter is a plug-in that modifies the appearance of an image, in most cases just the active layer of the image. Or for a more technical explanation, a filter is a special kind of tool designed to take an input layer or image, apply a mathematical algorithm to it, and return the input layer or image in a modified format.In other words, you can achieve some seriously cool effects with filters!For example, there are filters to help you distort your image as much as you like. There are filters that turn your basic drawing into an artistic sketch. You can apply lighting effects to your image. And there's plenty more filters for all sorts of other effects.

Applying a FilterWe're about to spend about 2 minutes (or less) painting a picture. It won't necessarily be a pretty picture, but it will be a picture.At the end, you will start to see the amazing power that filters provide. Using filters, anyone can make a bad sketch look interesting.Here's what to do:

1. Click the "Brush" icon on the main toolbar. This selects the brush as our current tool. The brush icon is the one that looks like this:

2. Draw a little stick man on your blank image. Don't worry if it doesn't look very good.

We'll be adding some effects to it next anyway.

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3. Now comes the fun part! We're about to add some filters for some special effects.

Select Filters > Map > Fractal Trace...:

If you don't have the Fractal Trace option, choose another filter that looks good.

4. A dialog will open that enables you to change the settings for this filter. Experiment with the settings, you will see them being updated in the little preview box:

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5. Once you're happy with your effect, click OK

So within a few minutes, we have created our own strange little stick man and then warped him until we can't even recognize him!

Experiment!Don't be afraid to experiment. You can always revert back to a previous state by clicking Edit > Undo or using Ctrl+Z.

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Path Tools If you use illustration software (such as Adobe Illustrator, Freehand, CorelDRAW, etc), you're probably familiar with the term "bezier curves". To draw bezier curves in those packages, you use a tool such as a Pen tool, or a Bezier tool. These tools enable you to create complex, professional looking illustrations with machine-like precision.In GIMP, the Path tool is kind of an equivilent of the pen/bezier tools in illustration packages. In fact, GIMP's Path tool used to be called the Bezier Selection tool.You can select the Path tool from the main toolbox. The Path tool icon looks like this:

Earlier, when we created our smiley face image, we used the Path tool to create the mouth.In that lesson, we didn't see the full potential of the Path tool. Although we managed to draw a nice smooth mouth, the full power of the Path tool becomes more apparent when you need to select complex shapes from an image.

ExampleTake the following image for example:

If we wanted to extract the leaf, so that there was no grass in the background, we could select the leaf using the Path tool.Here's what the photo would look like once we've drawn a path around the leaf with the Path tool:

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You can see the path following the edge of the leaf. You can also see "anchors", also known as "control points" at crucial points around the leaf. In total, there are 9 control points. You can also see the handles attached to one of the anchors (near the top of the leaf).Once you've drawn a path around your object, you can create a selection from it. Then, you are free to do whatever you like with it. For example, you could remove the background, like this:

Drawing Paths

The Trick To Creating Good PathsUsing the path tool can be a little tricky when you first start out. But hang in there. Take time to practice it, and before long, you will find it as easy as any other tool.Learning where to place anchors, and how to control them is a crucial part of learning the Path tool. Now, take a look at the anchors in the following image. In particular, look at their position:

Some anchors are located along a long smooth curved line. Other anchors represent a sharp change in the direction of the path (for example, at the tip of the leaf). There is a technique for doing this.Many beginners tend to create jagged curves that aren't smooth. This is because they create too many anchor points and don't know how to get a proper curve. The best way to get a long, smooth curve is to use less anchors with good positioning. Once you get the position right, the handles are there to adjust the angle of the curve as required.

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Take another look at the example above. You'll see that the long, smooth lines don't have many anchors. In fact, the anchors that are there, are being used simply to change the direction (or intensity) of the angle.When I created the above path, I clicked to create the anchor, then I adjusted the handles. If, after doing this, I found that the curve wasn't quite right, I simply "Undid" my anchor (Ctrl+Z) and tried again - this time placing the anchor in a different spot.

Straight LinesDrawing straight lines are the easiest thing to achieve with the path tool. To draw a straight line:

1. Click where you want the straight line to start 2. Click where you want the straight line to end

CurvesCreating a curve is where many beginners run into trouble. When creating curves, beginners often find that it's difficult to control exactly where the path runs. But drawing an accurate curve is not as difficult as it may seem.Three factors impact on getting a good curve with the Path tool:

• Position of the anchor • Length of the handles • Angle of the handles

Take a look at the following images:

The right image highlights the handles at the top left of the shape. The left image highlights the handles at the bottom, inner curve of the shape.You can see that on both curves, the handles are straight (or almost straight). On the left image, the large, outer curve needs larger handles than the smaller inner curve (on the right image). Also, both handles on the left image are roughly the same size. On the right image, the handles are different sizes (the lower handle is shorter). This is to faciliate the differently shaped curves on each side of the anchor.

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CornersOften when you draw a path, you will need to create a corner immediately after a curve. The curve will be going in one direction, but you need to change it with a sharp angle.You create corners by simply moving the handle across. For example, in the following image, the top handle is perpendicular to the other handle - it's roughly at a 90 degree angle.

Creating a CornerTo create a corner:

1. Create your shape until you get to the corner 2. Drag the handles (as per usual) to get the curve before the corner. Once you're

happy with the shape before the corner, release the handle (as per usual). Here's an example:

3. Now grab the handle and pull it across in the direction you want the path to go.

Example:

4. Once you're happy with the angle of the handle, click where you want the next

anchor. In this example, I wanted another curve, so I clicked and dragged:

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So, step 3 was the operative step. This is where we specified what direction the path was going to take, and how sharp the angle was going to be. Here's what would have happened if we had missed step 3:

Create Selection From PathOnce we've created the path, we can convert it into a selection. Once we have a selection, we can do whatever we want with its contents.Here's what our leaf looks like when I create a selection from it's path:

To create a selection from a path:

1. Open the Paths dialog box (Dialogs > Paths) 2. Right click on the path 3. Select Path to Selection

Don't worry, your path will remain after you've made your selection. In fact, you can create a selection from your paths as many times as you wish.

Removing The BackgroundSo, now that I've selected the leaf, I can do anything I like. For example, I could remove the background:

To remove the background, you can copy/paste the selection into another file.

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Alternatively, you can invert the selection, then delete the background or fill it with white.To invert the above selection, we'd first select the leaf, then we'd invert that selection (using Select > Invert).

Animated GIFsAnimated GIFs have been a popular image format amongst web designers for years. Perhaps this is due to the ease of creating an animation using this format.

What Is An Animated GIF?An animated GIF is simply an animated image, saved as a GIF. The animation occurs due to multiple "frames" being present within the image. Each frame represents a different image within the image. When the image is displayed, it runs through each frame, one after the other. This can occur quickly or slowly (as specified by the designer).Here's an example of an animated GIF:

In the above example, there are four frames.

1. The first frame is simply a photo 2. In the second frame, the word "Keep" is added 3. In the third frame, the word "Earth" is added 4. In the fourth frame, the word "GREEN" is added

Once the animation reaches the end (after the word GREEN), it starts again. This is called a "loop" - as it loops over and over the same animation. If it wasn't looped, it would stop at the fourth frame.

Creating Animations With GIMPGIMP provides a couple of ways of creating animated GIFs.

1. Using Script-Fu . Script-Fu is GIMP's scripting extension. It allows you to apply filters to your image that have an animated effect.

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2. Using Layers . Layers provide you with more options for your animated GIFs. Each layer becomes a different frame in your animation.

Many GIMP users don't actually realize that they can use GIMP to create animated GIFs.This lesson shows you how to create an animated GIF using the Script-Fu option of GIMP. We will take a JPEG image, and convert it to an animated GIF, applying a "rippling" effect in the process.

BeforeWe will take the following JPEG file, add a "rippling" effect, then create an animated GIF.

AfterHere is the finished animated GIF. It took about 5 minutes to convert the above JPEG image into this animated GIF using GIMP.

How to Create an Animated GIFI created the above animated GIF using the Script-Fu option of the GIMP. This is the easiest way of creating animated GIFs using GIMP. Script-Fu is a scripting extension for the GIMP.

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You access Script-Fu from the top menu and select the function you require. Script-Fu does the rest.To create an animated GIF using Script-Fu:

1. Open an image that you'd like to turn into an animated GIF:

2. From the Script-Fu menu, select an effect from the Animators option (I've chosen

Rippling here):

3. Set the parameters as required (you can experiment with these settings as much as

you wish):

4. Press OK 5. At this stage, a copy of your image will have opened in a new (untitled) window. To

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preview your animated GIF, select Filters > Animation > Playback:

6. Now a copy of your image will have opened in another window. But this time it's a

"Playback" window. Click Play/Stop or step through the animation as required.

7. Once you're happy with the animation, save the image (File > Save). If you're not

happy, go back and try again. 8. When prompted, select Save as Animation, then Export

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9. Click OK to continue to save as a GIF. Note the options under Animated GIF

Options.

That's all it takes to create an animated GIF using the GIMP!In this tutorial we used the "ripple" effect, but feel free to check out the other animation effects. Also, experiment around with the various settings of the different effects.

More Advanced Animated GIFsThe Script-Fu method is one way of creating animated GIFs with the GIMP. While it has its benefits, you may find this method slightly limiting. I mean, you might want to do more with your animations than create cool ripple effects and the like.

This lesson shows you how to create an animated GIF in GIMP using layers. This method gives you more control and flexibility than the Script-Fu method of creating animated GIFs. By using layers, you can be as creative as you like with your animated GIFs.If you're a regular GIMP user, chances are you probably already know 90% of what it takes to create an animated GIF. The other 10% is the easy part!

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BeforeWe will take the following image, add some text, then create an animated GIF.

AfterHere is the finished animated GIF. This animation simply loops through the layers in the image.

How to Create an Animated GIFI created the above animated GIF using layers.To create an animated GIF using layers:

1. Open an image that you'd like to turn into an animated GIF:

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2. Add some text (or anything else you like) to the image. Each layer represents a different frame in our animation. In this case, we have 3 layers of text. Now for the important bit. Write the amount of milliseconds each layer is to appear in the animation. Write this number in parentheses followed by "ms". For example: (1500ms). Just like in the screenshot:

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3. You can now preview your animated GIF. To preview, select Filters > Animation > Playback:

4. Now a copy of your image will have opened in another window - the "Playback" window. Click Play/Stop or step through the animation as required.

5. Once you're happy with the animation, save the image (File > Save). If you're not happy, go back and try again.

6. When prompted, select Save as Animation, then Export

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7. Click OK to continue to save as a GIF. Note the options under Animated GIF Options.

There you have it! That's all it takes to create an animated GIF using layers with the GIMP!

A Word On FilesizeAnimated GIFs can become very large if you're not careful. To keep the file size down, try not to use too many colors in your animated GIFs. Also, avoid dithering for the same reason.

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SummaryWell, that wraps up this GIMP tutorial. By now, you should be starting to know your way around GIMP. There's a lot to GIMP... but we've covered a lot in this tutorial.Here are some of the things we learned:

• We learned that GIMP stands for GNU Image Manipulation Program, and allows you to create and manipulate images.

• We created a basic image.

• We learned about tools that enable us to create more complex images.

• We learned about image formats and why it's important to save our images in the correct format.

• We learned how to resize images.

• We learned how to add color to an image

• We learned how to add text to an image

• We learned how to apply filters to images

• We created animated two GIFs - using two separate techniques.

• ...and much more

Where To From Here?Now that you've finished this tutorial, it would be a good idea to experiment. Create new images. Modify existing ones. Use the tools outlined in this tutorial to help you create an original image.

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