Chapter 12. Graphics Tools And Practical Devices

Table of Contents
12.1. Graphic Art And Image Manipulation
12.1.1. GIMP
12.1.2. Vector Graphic Applications
12.2. Digital Photo Cameras
12.2.1. Getting Started
12.2.2. Manipulating And Transferring Pictures to The Computer
12.2.3. Using The GIMP Plug-In
12.3. Scanners: ScannerDrake, Sane and XSane
12.3.1. Getting Started
12.3.2. Advanced Configuration
12.3.3. Other Scanner Interface Software
12.4. Printing Under Mandrake Linux
12.4.1. KPrinter's Dialog Description
12.4.2. Using KPrinter
12.5. CD Burning
12.5.1. Getting Started
12.5.2. Burning CDs
12.5.3. Going Further

12.1. Graphic Art And Image Manipulation

Linux offers a vast range of applications for graphic design and image manipulation. True to its Internet origins, Linux is a really interesting option for web designers. With power-user tools such as Screem and GIMP, especially combined with Linux's server capabilities, any Internet application can become a reality.

Therefore, this chapter will mainly concentrate on GIMP, and introduce other interesting applications you may want to discover on your own.

12.1.1. GIMP

What is GIMP

The GNU Image Manipulation Program (GIMP) is a free software program challenging proprietary applications such as Adobe Photoshop or Corel PhotoPaint. In many aspects, GIMP is a flagship application of the Free Software movement, not only because of the amazing technical excellence it demonstrates, but also because of the astonishing creativity it exposes.

GIMP allows advanced photo editing tasks such as cropping, resizing, painting, drawing, modifying colors, etc. Its true beauty lies in its extensibility and its scripting options, which open GIMP to a full integration in programs and scripts. This enables GIMP to perform as a mass production image rendering application.

GIMP runs on most Unix-compatible systems, it relies on a large group of volunteer developers and it is therefore in constant evolution. You are invited to contribute, test the latest releases, write plug-ins and scripts. GIMP is a live example of what free software does best, join in and have fun!

Strengths

For normal users, GIMP will seduce through its advance functions for web images and formats. Easily create animations and optimize your art for web publishing. You will also greatly enjoy GIMP's extensive photo manipulation features.

Power users, publishers and document management specialists will truly benefit from GIMP through its advanced scripting capabilities and API's.

Weaknesses

GIMP, like most graphic design Free Software applications, suffers from the fact that pre-press standards, such as the Pantone process, are proprietary, and closed. GIMP being open-sourced, there is no usable implementation of these standards. Also, this world is dominated by Apple-compatible computers and you will therefore have to put in the extra effort to print professionally with GIMP, but it is possible.

Where to find more information

GIMP includes extensive documentation available through the help menus. It offers two searching interfaces, through content and index.

type: F1

On the net, GIMP is a very well documented application and a lot of information is freely available. We particularly recommend GIMP Manual written by Karin Kylander and Olaf S along with Grokking The GIMP. Both books are available on The GIMP web site. This link will also guide you towards a series of more specific resources such as FAQ and Tutorials.

12.1.1.1. Getting Started

Concepts

GIMP embraces differences. Therefore, there are usually many ways to achieve the same goal.

Menu

From GIMP's main window (called the ToolBox), you can access the basic program options such as opening a file, creating a new file, etc.

Right-clicks

Once an image is opened or created, you can right-click in the image window and access the image's specific options such as: Open, Close, Save, Save as, Dialogs, etc.

Shortcut keys

There is a default set of shortcut keys you may use to accomplish the most common tasks, such as saving files, accessing brush dialogs, etc. Note that you can easily customize that set according to your most common use of GIMP. Also, they are always available, as long as a GIMP window has keyboard focus.

Layers, image modes and file formats

One of the key concepts to grasp in order to truly benefit from such an application is the one about layers, formats and file modes. Roughly put, numeric image editing added a 4th dimension to art: layers. Images are built vertically (so are animations) and each layer has user-defined properties which determines other tasks that can be accomplished. File mode defines the inner logic of the graphic elements. Hence, an RGB image doesn't allow for the same operations and capabilities as, gray scale image, i.e. color. Finally, the file format also impacts on which operations can be done on that file, especially for saving.

All that to illustrate that if you face difficulties accomplishing any task described below, check these 3 elements before running to conclusions.

12.1.1.2. Starting GIMP

From the console

To start GIMP from the console, type gimp &. You can also start GIMP and open a file. Type gimp filename.ext &.

From the program menu

GIMP is accessible from the

GNOME Menu->Program->Graphics->The GIMP

KDE Menu->Graphics->The GIMP

When you open GIMP, unlike Photoshop on Windows, only the basic ToolBox appears. It offers GIMP's core functions and allows you to initiate anything forward.

Figure 12-1. GIMP's Toolbox

12.1.1.3. Basic Operations

Here are a few basic operations:

Opening a file

Figure 12-2. Opening from the ToolBox

Shortcut: Ctrl-O

File->Open

Your image will appear in a new window. From that window, you may access context-sensitive menus available from the right mouse button. We will oversee these options a bit further.

GIMP supports many file formats. Depending on the file format you want to open, you may have to answer questions pertaining to the details of that format and conversion information.

Creating a new file

Shortcut: Ctrl-N

File->New..

Then appears a new window dialog which enables you to determine width and height in pixels, but also its real physical dimensions in inches or centimeters. You may also specify the file's type. Once you click OK, the image window appears and you may edit it as you would any other bitmap image, mainly using the ToolBox.

Figure 12-3. Creating a New File

Saving Files

Shortcut: Ctrl-S

File->Save

File->Save As

The first time you save or save as...

Figure 12-4. Saving Files

this interface pops up and allows you to set the name and location of your image. More importantly, it is the place to define the file type such as JPEG or PNG in the case of web publishing.

Recurrent Save And Auto-Save

If you hit Ctrl-S once the name, location and file type are known, you won't be prompted with the previous window. To change file types, simply Save as.

Note

Often, new users, at the stage of saving their work, run into multiple problems such as losing layers or simply damaging their work. Most of these problems come from the specific options allowed for each file format. First, check if the format you specified supports the image mode defined. Second, if you used layers, check if the file format supports them. If you have no clue, save in XCF, GIMP's own file format. You can always try multiple Save as later.

12.1.1.4. Basic Image Manipulation

The ToolBox

The ToolBox contains your basic graphic design tools. If you move your mouse over any item, its name will appear in a yellow window. Each of them possesses its own set of options, accessible by double-clicking the icon. We won't detail each tool in this guide as it would be to long. Experiment with each tool. Remember that layers may affect tools behavior. For example, the rectangular select tool won't allow to delete part of the background layer.

Note

If you close the ToolBox, you close GIMP and all windows. But if you close any other window, it will only effect that window.

Image window

Figure 12-5. GIMP Picture

This window manages either new or opened images. This is where you can right-click to view image-specific menus. This is also where tools selected in the ToolBox may be used.

View Size

At the very top of the window, you see a numeric value in percentage. This is the zoom ratio. You can increase it or decrease it by right-clicking and accessing the View menu, or:

  • to increase, press +;

  • to decrease, press -.

You can also launch a window navigator which allows to pan and resize a window. You can do this with Ctrl-Shift-N, or by right-clicking and accessing the View->Nav. Window... sub-menu.

Undo And Redo

Also very important, you can undo and redo all your operations. You can specify the number of available undos. Note that it has a large impact on RAM and too many undos may make a large image impossible to manipulate.

Right-click+Edit->Undo

Right-click+Edit->Redo

or:

Ctrl-Z = undo

Ctrl-R = redo

Cut And Paste

GIMP allows you to cut (Ctrl-X) and paste (Ctrl-V) within any window, as well as between any GIMP window.

You can also paste as layers.

12.1.1.5. Layers, Channels And Path

Layers are one of the true innovations of computer-generated graphic design. It brings a fourth dimension and a vertical concept to the work. GIMP allows for an unlimited number of layers. Each layer has a specific set of properties.

To access the layers dialog:

Right-click+Layers->Layers, Channels & Path...

Figure 12-6. Layers Dialog

You may also access the layers' menu by right-clicking on the layer.

12.1.1.6. Filters

Filters are a set of programmed actions which modify your image according to some specified options. GIMP offers a vast range of filters such as blurs, noise effects or image enhancement operations. Filters may be applied to selections and layers.

The filters' menu is accessible through:

Right-clicking->Filters

Figure 12-7. Filter's Dialog

12.1.1.7. Dialogs

Dialogs basically give any tool further options. There are quite a large number of them and for the purpose of this introduction, we will only discuss the Color Selection and Brushes dialogs.

Color Selection

Figure 12-8. Color Selection Dialog

It allows to determine the background and foreground colors that appears at the bottom of the ToolBox. You may specify any color according to the possibility of the image type you defined. Rule of thumb, always work in RGB, so you can always save as later.

To access the Color Selection dialog, double-click on the square which holds a black and a white rectangle at the bottom left of the ToolBox.

Brushes

This dialog determines the type and size of the brushes (which applies to the Pencil and Fuzzy brush tools).

Right-click->Dialogs->Brushes

Figure 12-9. Brushes Dialog

12.1.1.8. Printing

GIMP is ideal for web development but printing from GIMP is sometimes tricky. Because of the absence of CMYK and Pantone Process images, GIMP is not ideal for pre-press work.

GIMP internally supports many printers and it's always feasible to filter images through GhostScript or print to file (PostScript). Therefore, you can print images relatively easily. Remember to adjust your resolution to match your printer's capabilities.

There is quite a lot of online documentation to further your knowledge about printing with GIMP. In this book, it is simply impossible to address this issue.

12.1.1.9. Advanced Features

It is way beyond this user guide to detail GIMP's advanced features. Here is an avant-goût of the possibilities.

Scripting

GIMP offers several scripting interfaces for power users. These may automate almost any GIMP operation and allow external programs to talk to GIMP. You may use some script more or less like filters by:

right-clicking and accessing the Script-Fu menu.

Script-Fu is the first GIMP scripting language, but there are also other APIs such as GIMP-Perl, to use perl scripts within GIMP.

Plugins

Plugins are external applications which extend a program's core functionalities. GIMP, like Photoshop, relies on a vast range of plugins to push its boundaries. You may also contribute plugins to the community as most of them are free to use and distribute.

Xtns->Plugin Details to view all installed plugins.

12.1.1.10. Conclusion

Hopefully, this brief introduction caught your interest for this amazing application. GIMP is now a first-class application and should be considered by any Linux web developer as the definite choice for web designs.

12.1.2. Vector Graphic Applications

Both the GNOME environment and the KDE project are now offering promising vector graphic applications. Dia is now mature and, if properly used, a very useful application.

12.1.2.1. Diagrams

If you need to pull out system diagrams, flowcharts, and UML documentation, Linux has one great option, Dia, and a promising option in the KDE office project.

Dia

Dia is a very interesting vector-based diagram application and it can be considered as an alternative to Microsoft Visio. It contains a set of predefined symbols according to one of the 19 basic diagram you may use. Dia is particularly interesting for document management since its native format is XML-based, compressed by default, and therefore very light and flexible.

Dia offers many common look-and-feel features, like GIMP. Right-clicking in the image will give you image-specific menus, and allow you to modify the image to your needs.

From the console, type: dia &.

Kivio

Very much like Visio, but at a very early stage. Well integrated in the KOffice suite, it really shows great potential, but Dia remains much more complete and ready to use, primarily because of the quantity of symbols available.

To open Kivio, access either the GNOME or KDE menu, then the Office->Graphs->Kivio sub-menu.

12.1.2.2. Vector Design

Kontour, a vector-based drawing program, is part of the KOffice suite. It's a nice application and it shows many promises, but it is no where near professional commercial products of this category. It's great for beginners, amateurs and kids.

To start Kontour, access either the GNOME or KDE menu, then the Multimedia->Graphics->Kontour sub-menu.


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