XP Practical PC, 3e Chapter 13 1 Working with Graphics

XP Practical PC, 3e Chapter 13 2 Working with Graphics In this Chapter, you will learn: –What kind of graphics I can work with on the PC –When to use bitmap graphics –How to prepare graphics for Web pages –When to use vector graphics –How to create 3-D graphics –How to edit a digital photo –About Digitizing devices

XP Practical PC, 3e Chapter 13 3 What kind of graphics can I work with on my PC? Graphics or images are the pictures used in documents to add interest and visual explanations. Using graphics software, you can create, edit and store graphics on your computer. You can get graphics from many sources, including downloading from the internet, scanning paper sources, and buying clip art collections. There are two basic types of images you may use – bitmaps and vector graphics.

XP Practical PC, 3e Chapter 13 4 What kind of graphics can I work with on my PC? A Bitmap vs. a vector graphics image

XP Practical PC, 3e Chapter 13 5 When to use bitmap graphics In a bitmap graphic, the image is represented by a grid of colored dots. Bitmap images can be used to represent photo type images. Bitmap image file types include BMP, TIFF, GIF and JPEG. Paint software such as Adobe Photoshop and Corel PhotoPaint will create and edit bitmaps.

XP Practical PC, 3e Chapter 13 6 When to use bitmap graphics Bitmap quality depends on resolution and color depth. Higher resolution images show detail clearly. The number of color variations in an image is called color depth. True color, a 24-bit color depth produces 16.7 million colors but takes 3 times the storage space of a 256-color image.

XP Practical PC, 3e Chapter 13 7 When to use bitmap graphics The Windows Paint program You can change to color of an area with the fill tool The toolbar offers many tools for drawing and editing images A square on the grid is one dot in the image This window shows the actual image

XP Practical PC, 3e Chapter 13 8 Preparing graphics for Web Pages Web page graphics need to load as quickly as possible and still look good. Web graphics should be less than 20KB. Graphic sizes can be reduced by: –Resizing or scaling the graphic or using a thumbnail with a link to a bigger graphic –using a compressed format such as GIF or JPEG –reducing color depth to 256-color or dithered 16-color

XP Practical PC, 3e Chapter 13 9 Preparing graphics for Web Pages 256 color, dithered 16-color, and non-dithered 16 color

XP Practical PC, 3e Chapter When to use Vector Graphics In a Vector graphic, the image is represented by points, lines, arcs and other geometric shapes. A shape consists of line segments (vectors) with different widths and fill colors. Vector graphics are used for diagrams, line drawings and computer-aided design (CAD).

XP Practical PC, 3e Chapter When to use Vector Graphics The advantages of a vector graphic include: –They are usually small –They can change size with no loss of quality –Each shape is independent and can be modified individually Vector graphics file types include EPS and WMF. Vector graphics can be created/edited by packages such as Adobe Illustrator and Corel Draw.

XP Practical PC, 3e Chapter When to use Vector Graphics Using Micrografx software to add vectors to an image

XP Practical PC, 3e Chapter Creating 3-D graphics 3-D graphics appear to be three dimensional and also allow you to view the object from all angles. When creating a 3-D object, you produce a line drawing called wireframe of each surface of the object. Then you apply surface information to each surface (called rendering). This is similar to draping a covering over a frame.

XP Practical PC, 3e Chapter Creating 3-D graphics You also will specify a light source and the software will create bright spots and shadows. This process is called ray tracing. The rendering process can require extensive computer power and time. The finished image are very well defined with unflawed surfaces.

XP Practical PC, 3e Chapter Creating 3-D graphics The rendering process in creating a 3-D image

XP Practical PC, 3e Chapter Hardware – Digitizing devices An image that you can work with on your PC must be in digital format. A digitized image has been converted to a series of 0s and 1s. Images can be digitized by devices such as graphics tablets, scanners or digital cameras.

XP Practical PC, 3e Chapter Hardware – Digitizing devices A graphics tablet is like a drawing pad. Using a pen-shaped stylus you can draw on the pad. The images drawn on the tablet are then converted to bitmap graphs. The tablet is sensitive to where you touch the stylus and how much pressure is applied.

XP Practical PC, 3e Chapter Hardware – Digitizing devices A graphics tablet

XP Practical PC, 3e Chapter Hardware – Digitizing devices Scanners can digitize text, images, and bar codes. Flatbed scanners resemble small copiers. Scanning software allows you to adjust the size, resolution and other characteristics of the scanned image. OCR software allows you to scan and interpret text so that it can be read into word processing software.

XP Practical PC, 3e Chapter Hardware – Digitizing devices Scanning with a flatbed scanner

XP Practical PC, 3e Chapter Hardware – Digitizing devices Digital cameras take photos much like a regular camera, but store them as bitmap images instead of exposing the image on film. Digital cameras store images in a variety of ways, such as on a PCMCIA memory card, a floppy disk or in flash memory. Flash memory holds data without a constant supply of power and then transfers the pictures to the PC over a cable.

XP Practical PC, 3e Chapter Hardware – Digitizing devices A digital camera

XP Practical PC, 3e Chapter Making your own CDs Editing digital photos Remove Ceiling light Get rid of red eye Fix five o’clock shadow Sharpen edges

XP Practical PC, 3e Chapter What do you think? Shoes, UFOs, and Forrest Gump 1.In your opinion, should photos and videotapes be allowed as evidence in civil and criminal trials? 2.Do you think that it would be possible for someone to use doctored photos and videotapes to convince people that a fake event actually took place? 3.Do you have a set of criteria for judging the authenticity of newspaper and TC images?

XP Practical PC, 3e Chapter Chapter Summary You should now be able to: –Understand the differences between bitmaps and vector graphics –Know when to use each format –What to do for Web page graphics –How to create 3-D graphics –How to edit a digital photo –Understand the basic types and uses of Digitizing devices