1. Chapter 14 Working with Graphics

2. 2Practical PC 5 th 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

3. 3Practical PC 5 th Edition Chapter 14 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

4. 4Practical PC 5 th Edition Chapter 14 What kinds of graphics can I work with on my PC?

5. 5Practical PC 5 th Edition Chapter 14 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

6. 6Practical PC 5 th Edition Chapter 14 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

7. 7Practical PC 5 th Edition Chapter 14 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

8. 8Practical PC 5 th Edition Chapter 14 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”

9. 9Practical PC 5 th Edition Chapter 14 How do I create 3-D graphics? Creating a 3-D graphic

10. 10Practical PC 5 th Edition Chapter 14 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+

11. 11Practical PC 5 th Edition Chapter 14 Hardware: Digitizing devices 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

12. 12Practical PC 5 th Edition Chapter 14 Hardware: Digitizing devices 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

13. 13Practical PC 5 th Edition Chapter 14 Hardware: Digitizing devices Graphics Tablet Scanner

14. 14Practical PC 5 th Edition Chapter 14 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?

15. 15Practical PC 5 th Edition Chapter 14 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