Chapter 14 Working with Graphics. 2Practical PC 5 th Edition Chapter 14 Getting Started In this Chapter, you will learn: − About different graphics you.

Chapter 14Working with Graphics

2 Practical PC 5th Edition Chapter 14

Getting Started

• In this Chapter, you will learn:− About different graphics you can work with on

your PC− When to use bitmap graphics− Which format to use− When to use vector graphics− How to create 3-D graphics− About Hardware: Digitizing devices


What kinds of graphics can I work with on my PC?

• Pictures that you can create, modify, download, and transmit using your PC are referred to as graphics or images

• You can obtain ready-made images– Clip art and stock photo collections – Pictures scanned from books or magazines

• You can use photos from your own collection or your digital camera

• You will typically work with two types of graphics: vector and bitmap


What kinds of graphics can I work with on my PC?


When should I use bitmap graphics?

• Bitmap graphics, sometimes called raster graphics, represent an image as a grid of colored dots– Photograph-like images used for photos and Web page images– Stored as BMP, TIFF, GIF, PNG and JPEG– Manipulate the image using paint software

• Quality depends on resolution and color depth– Resolution is the width and height of the grid that holds the dots and

each dot is assigned a color code– Color depth is the number of bits required to store the color number.

The more colors, the more storage space needed• 1-bit color depth produces a black and white image• 8 bit color depth produces 256 colors• 24-bit color depth produces 16.7 million colors, sometimes referred to as

true color


How do I know what format to use?

• File format depends on how you plan to use it– For printed publications, use a format that retains a high resolution

and 24-bit color depth– For the Web or e-mail attachments, you can use more compact

formats• To reduce file size

– Shrink the physical dimensions of the image– Use compression techniques– Reduce the color depth

• Rules of thumb– JPEG format offers the best quality in the smallest file size– For diagrams, logos, screenshots, and images containing text, use PNG

format– GIF works best for logos and images that contain solid blocks of color

or a limited range of colors


When should I use vector graphics?

• Vector graphics consist of a set of geometrical shapes– Each shape is defined as a series of line segments called vectors– Vector graphics are ideal for diagrams, line drawings, and computer-

aided design (CAD)• Vector graphics resemble line drawings more than

photographs– File size tends to be small since shapes can be stored efficiently– Graphics can shrink or expand with no loss of quality– You can modify each shape in a vector graphic independently

• Vector graphics are often saved as EPS, WMF, or CAD formats• Drawing software provides tools to create and manipulate

vector graphics


How do I create 3-D graphics?

• 3-D graphics contain objects that appear three-dimensional – 3-D objects have the data necessary to display, rotate, and view from

any angle– 3-D objects are composed of vectors and are created using same

drawing and CAD software that produces 2-D graphics• To create a 3-D object

– Produce a wire frame or a line drawing outlining every surface of the object

– Render the object by applying texture, transparency, and color to its surface

– Your PC automatically determines where to put highlights and shadows using a process called ray tracing

– Rendered 3-D graphics have a new-car-brochure look that is sometimes referred to as “super-realistic”


How do I create 3-D graphics?

Creating a 3-D graphic


Hardware: Digitizing devices

• Digitizing converts an image into a series of 1s and 0s that your PC can store and display

• Digitizing devices allow you to convert real objects, such as a photo, into a digital format

• Graphics tablet− Works like an electronic canvas− Use a pen-shaped stylus to “paint”− Some graphics software does not support the use of a

graphics tablet− Connects to USB port− Cost from U.S. $70 to $500+



• Scanner− Reads text, images, and bar codes− Typically used for flat objects such as photos− Flatbed scanners are the most popular and resemble

small photocopiers− Connects to USB port− Basic unit costs about U.S. $49− Bundled with software

• Scanning software allows you to preview a scan, select a resolution, and initiate a scan from your PC

• OCR (optical character recognition) software allows you to convert an image into a text file



• Digital camera− Takes photos and stores them as bitmap images− Connects to USB port − Can also insert memory card from camera into PC− Transferred images are stored on your PC− Camera prices depend on resolution measured in

megapixels. A basic camera costs under U.S. $200 and mid-range cameras cost $200-$1000

− You can open files using paint or photo editing software



Graphics Tablet Scanner


Shoes, UFOs, and Forrest Gump?

• What do you think?– In your opinion, should photos and videotapes be

allowed as evidence in civil and criminal trials?– Do you think that it would be possible for someone

to use doctored photos and videotapes to convince people that a fake event took place?

– Do you have a set of criteria for judging the authenticity of newspaper and TV images?


Chapter Summary

• You should now know:− About the kinds of graphics you can work with

on your PC− Know when to use bitmap graphics− Know what format to use− Know when to use vector graphics− How to create 3-D graphics− About digitizing devices

Chapter 14 Working with Graphics. 2Practical PC 5 th Edition Chapter 14 Getting Started In this Chapter, you will learn: − About different graphics you.

Documents

vectors vector graphics

types of graphics

raster graphics

different graphics

color number

bitmapwhat kinds of

color depthresolution

color depthfor