chapter 13 working with graphics
DESCRIPTION
Chapter 13 Working with Graphics. 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 - PowerPoint PPT PresentationTRANSCRIPT
Practical PC, 3eChapter 13
1
XP
Chapter 13
Working with Graphics
Practical PC, 3eChapter 13
2
XPWorking 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
Practical PC, 3eChapter 13
3
XPWhat 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.
Practical PC, 3eChapter 13
4
XPWhat kind of graphics can I work with on my PC?
A Bitmap vs. a vector graphics image
Practical PC, 3eChapter 13
5
XPWhen 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.
Practical PC, 3eChapter 13
6
XPWhen 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.
Practical PC, 3eChapter 13
7
XPWhen 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
Practical PC, 3eChapter 13
8
XPPreparing 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
Practical PC, 3eChapter 13
9
XPPreparing graphics for Web Pages
256 color, dithered 16-color, and non-dithered 16 color
Practical PC, 3eChapter 13
10
XPWhen 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).
Practical PC, 3eChapter 13
11
XPWhen 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.
Practical PC, 3eChapter 13
12
XPWhen to use Vector Graphics
Using Micrografx software to add vectors to an image
Practical PC, 3eChapter 13
13
XPCreating 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.
Practical PC, 3eChapter 13
14
XPCreating 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.
Practical PC, 3eChapter 13
15
XPCreating 3-D graphics
The rendering process in creating a 3-D image
Practical PC, 3eChapter 13
16
XPHardware – 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.
Practical PC, 3eChapter 13
17
XPHardware – 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.
Practical PC, 3eChapter 13
18
XPHardware – Digitizing devices
A graphics tablet
Practical PC, 3eChapter 13
19
XPHardware – 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.
Practical PC, 3eChapter 13
20
XPHardware – Digitizing devices
Scanning with a flatbed scanner
Practical PC, 3eChapter 13
21
XPHardware – 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.
Practical PC, 3eChapter 13
22
XPHardware – Digitizing devices
A digital camera
Practical PC, 3eChapter 13
23
XPMaking your own CDs
Editing digital photos
Remove Ceiling light
Get rid of red eye
Fix five o’clock shadow
Sharpen edges
Practical PC, 3eChapter 13
24
XPWhat 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?
Practical PC, 3eChapter 13
25
XPChapter 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