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Create Graphics with GIMP

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PCQ Bureau
New Update

A slice of pizza, a cup of steaming coffee, some ideas in mind, GIMP on your desktop and you can create magic!

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What is GIMP?

GIMP or GNU Image Manipulation Program is undoubtedly the most powerful image manipulation program available under Linux. (A Windows version of GIMP is also available.) It was written by Peter Mattis and Spencer Kimball in 1995 and has since evolved tremendously to become a standard in image manipulation under Linux. GIMP also has its own mascot, Wilber, the gimp, a cute wolf-like character.

GIMP on your machine

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GIMP installs by default with PCQ Linux 7.1 that was distributed with our July 2001 issue. You can launch it by choosing GIMP from the startup menu or typing ‘gimp’ in a terminal window.

In case you don’t have GIMP installed on your hard disk, locate it on our July 2001 CD and install the RPM.

The GIMP interface

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When I was first introduced to GIMP three years back, I would often get frustrated by its deceptively simple un-Windows like interface, thinking it can’t do much. It took me a few projects to start exploiting all its features and now I believe there’s nothing this feature-rich program can’t do. Mac users, however, will find themselves at home with GIMP.

GIMP opens a very modular interface that sits in one corner of your desktop while you work. The work window opens separately and floats independently. On right-clicking the image window, a floating toolkit opens and the menu therein does everything possible.

GIMP’s toolbox is highly customizable. You can add your preferences, like custom image size for new image, color transparency, preview size, and undo levels (by default GIMP gives you unlimited undo, that is, you can undo as many times as your RAM allows). You can also add custom brushes, gradients, patterns, and plug-ins and extend the functionality of the program. The only hurdle you may face is that GIMP does not support CYMK output.

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XCF is GIMP’s native file format for saving images. GBR is for brushes and PAT for saving patterns. GIMP can also read and write almost every image format file including MIME and URLs.

One of the most important and useful features while making a complex image is that of layers. The layering features of GIMP are advanced and easy to learn. You can also edit a specific color channel or selection mask. These options are available under Channels that is a part of Layer and Channels window. Color editing is most useful for restoring scanned photographs or adding artistic effects to images.

GIMP for the impatient: Using Script-fu

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GIMP is an intricate application and that makes the learning curve steep. However, for instant gratification and hurried tasks, there’s Script-fu–GIMP’s own scripting language. Script-fu automates routine tasks and eases complex modification procedures by stringing multiple tasks into a single command.

Script-fu is a full-fledged programming language that has been encompassed in GIMP to allow greater control over its functions. GIMP includes default Script-fu scripts that can create logos and Web page themes. Tasks such as adding a bevel, drop shadow, border, blend, and effects such as carve, chrome clothify, or ripple can be applied by mouse

clicks.

Some very interesting affects are available in Script-fu, like the predator. The script changes colors of layers so that they form what looks like a thermal image similar to what the predator sees in the movie of same name. The animator script generates an excellent animation whereas the spinning globe script can map your image in the form of a spinning globe. The best part about applying Script-fu is that you can work on a copy and your original image remains intact. Let us now make a plaque using Script-fu.

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Choose Script-fu from the Xtns menu. Choose the option Logos>Neon. Write PCQuest in the text field, choose a font and size. Apply Style. A lovely plaque is ready.

Creating images

Like all image manipulation programs, GIMP too thrives on basic drawing and painting techniques. It, however, proves to be very versatile and customizable.

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As mentioned above, the root menu items and options are available on right clicking the mouse button over the work area.

The main toolbox opens when GIMP loads. It has two drop-down menu items, File and Xtns, which have other options and operations within them. On the left of the Toolbox are the icons for various tools. The selected tool shows darker than others and you switch tools by clicking on them. To the right of tools are the active color boxes. The color selector shows current background and foreground colors with the foreground color on the top. Selecting either of the color swatches pops up a very slick color selection dialogue. GIMP uses RGB color format.

Working with images

Selecting Open from the Tools menu results in a standard open dialogue form where you can open the desired image. You can leave the file type determination set to Automatic. To start a new artwork, click on the Files menu and click New. Copy and cut-paste is very straightforward–use the Edit menu by right clicking on the image or by simply selecting and doing Ctrl+X and Ctrl+V. However if you are doing a lot of copying, cutting and pasting, you can take advantage of the named buffer. This lets you name your selections so that you can work with multiple selections. More advance selections can be made by creating a union between an existing selection and a new one. To create selections around complicated objects, it is best to use the intelligent scissors tool to select the general shape of the image and converting it into a brazier curve.

Once the selection is made, you can sharpen it to look prominent or blur it so that it blends in the background. You can also put a border around it or make it grow or shrink

radially.

Select by color lets you select regions in your artwork based on their color. You can replace, add (union), subtract or intersect them.

Stroke is an interesting tool from the GIMP toolkit. It uses the current brush and foreground color to draw a line wherever there is a selection edge. This is useful for drawing simple rectangles, ellipses and curves with selection tools. You can experiment a lot here by using different brushes and tools to create some very good effects.

The Layers menu, which is available from the main menu pops up a layers dialogue. I recommend using layers for all your artwork, complex or simple. It is easy to edit and apply changes or transparency to a layer and produces better results. You can also save each layer

separately.

GIMP provides unlimited undo and redo. So you can go as back as the RAM of your computer allows. This is a very old feature of GIMP that has now been incorporated by many an image manipulation

software.

GIMP starts to shine when it comes to image filters. Filters are modification routines that change the properties of an image. For example, a filter can sharpen an image or make it look like embossed stone or stained glass. While some filters perform a single task, others have a full range of configuration options and settings. The filters come as plug-in modules and there are a number of them available from the routine blur and sharpen to lens flare and lighting effects.

Scanning an artwork

TWAIN support for scanners is provided by the SANE (Scanner Access Now Easy) Plug-In. The version of GIMP shipped with PCQ Linux 7.1 is integrated with XSANE for hassle free scanning.

Printing your artwork

Printing from GIMP is simple. You get it from the File menu.

Taking screenshots

Screenshots can be very useful for people who want to demonstrate something from a computer screen. The screenshot tool is found in File>Acquire>Screenshot from the Toolbox main menu. You get the option to grab the entire screen or grab the active window. If you are taking screenshots of a specific window you also have the option of not including decorations such as title bars, or a handle for resizing the window.

Mailing images

You can use the mail-image plug-in to mail an image over the Internet from within GIMP.

Net-Fu

GIMP can do something very unusual for a graphics program–it can run as a server. Bryan Livingston of CoolText.com used to be the maintainer of Net-Fu. (I’m not sure if he still is). Net-fu is the Web-based interface to Script-fu. To experience its magic, visit

www.cooltext.com.

Creating a fire

Here’s a small tutorial on making a realistic-looking fire using GIMP in less than 10 steps. See the graphic for end effect.

  1. Create New image.
  2. Choose Gradient. Open the gradient editor by double clicking the active gradient tool. The German_flag_smooth gradient makes a good flame base, so we will select that, and click the Edit button.
  3. The sliders under the gradient let you split segments, and change colors among other things. By right clicking just below the absolute left gradient’s segment, between the black and white triangles, we can change the color of that segment’s leftmost color. Change the color from black to alpha by select Load From> and clicking the checkerboard color
  4. Make sure that you have the new gradient selected. Now double click the blend tool icon to open its options. Change the blend item to custom gradient and click Close
  5. Create a gradient on your new image that looks like the accompanying figure.
  6. Right click on your work image and go down to Filters>Distort>Iwrap
  7. Start distorting the image by selecting ‘Move’. Hold down your left mouse button on the preview pane and just move it up and down across the image.
  8. The next step is to Swirl Counter Clockwise and Clockwise until you have something looking like a fire.
  9. This is what your fire will look like.

The Net is full of various tutorials and howtos, and we will follow up this article with a few of our own as well, but two resources, Grokking the GIMP and the GIMP user manual provide all essential ingredients to becoming a GIMP expert. For quick reference, you can also keep a copy of GIMP Essential Reference or GIMP Pocket Reference handy.

Swati Sani runs Sanisoft  <www.sanisoft.com>

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