Graphics

What is a Graphic ? A Graphic is an image or a picture e.g. Pictures can be either drawn or painted. Pixel - Stands for Picture Element

What is a draw document ? A draw document is often made up of objects such as rectangles, circles and lines. They can be easily moved, deleted or re-sized. You can also add text and clip art to a drawing. Draw documents can be useful for presentations, charts and illustrations. They can also be used to for creating newsletters having text flow from one column to another.

What is a paint document ? Paint documents are mostly used for illustrations. You can use the same tools as you would to create a drawing, except you can ’ t easily move parts of a picture. In a paint program you are able to erase parts of a picture easily. Special effects are also available in painting programs, such as tints, airbrush and brushstroke effects. Scanned images can also be edited to improve the quality or distort the image.

How do paintings and drawings differ Drawings are made up of objects that can be moved and re-sized independently of each other. Paintings are made up of separate pixels. Shapes drawn in a painting program become part of the same picture.

Practical 1 1) Make a drawing of a Logo for a no smoking sign using a drawing package. 2) Make a painting of a logo for wheelchair access using a Paint program.

Exercise 2 1) Create Logo for a company using a paint or draw program. 2) Create a Letterhead for a company using office, include the Logo you created before. 3) Create an advertisement for your company. Make the Ad A5 size (half A4).

Hardware for Graphics The hardware required in designing computer graphics is usually more powerful than in most other computer applications. Computer graphic systems are usually stand- alone machines and are not networked. Computers that are used in graphics systems usually have very fast processors and have huge amounts of RAM and storage space.

Input Devices Special Input devices can be used to create computer graphics. Listed below are some common input devices used in graphic manipulation. Mouse Digital Camera Scanner Light pen Graphics Tablet Joystick

Output Devices Output devices include a variety of monitors and printers. The quality of monitors and printers used in professional graphic systems are usually much better than those used on a personal computer. Listed below are some of the most common devices. VDU - Visual Display Unit CRT - Cathode Ray Tube Multisync Monitor Ink Jet Printer Laser Printer

The Power Required for Graphics Manipulation A large amount of Ram and a powerful CPU are essential for creating and manipulating graphic files efficiently. The production of a graphic image on the screen requires a lot of mathematical calculations by the processor. The faster this can be done the greater the visual effect, especially in games that have animations. In graphical manipulation the storage devices used also need to have a greater capacity. Many graphics files won ’ t fit on a floppy disk. For this reason graphics files are usually compressed so that less space is required to store them. Hard drives that are used in graphical manipulation have storage capacity in Gigabytes. CD-ROM are also used to store graphics, that don ’ t have to be changed. CD-ROMS have been the popular choice for games over the last couple of years because of there ability to store a large amount of files and they are cheap to produce.

For example the size of one photo taken with the digital camera is about 900 K. At this rate only one picture would be able to be stored on a disk. Most computers that are used in graphic work have an enhanced graphics card installed. These cards often have their own memory and aid in graphic manipulation.

Graphics data is manipulated in a special storage area called video RAM, or a frame buffer. This is sometimes part of the RAM or is a separate chip on the graphics card. This is something to be aware of when purchasing a new computer as many only include a basic-level graphics card. The cost of a specialised graphics computer can run into several thousands of dollars.