1. Chapter 13 Working with Graphics
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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
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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.
Practical PC, 4e
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4. What kind of graphics can I work with on my PC?
A Bitmap vs. a vector graphics image
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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 Microsoft Paint will create and edit bitmaps.
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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.
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7. When to use bitmap graphics
The Windows Paint program
Practical PC, 4e
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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
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9. Preparing graphics for Web Pages
256 color, dithered 16-color, and non-dithered 16 color
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10. 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).
Practical PC, 4e
Chapter 13

11. 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.
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12. When to use Vector Graphics
Working with vector graphics
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13. 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.
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14. 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.
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15. The rendering process in creating a 3-D image
Creating 3-D graphics
The rendering process in creating a 3-D image
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16. 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.
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17. 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.
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18. Hardware – Digitizing devices
A graphics tablet
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19. 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.
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20. Hardware – Digitizing devices
Scanning with a flatbed scanner
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21. 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.
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22. Hardware – Digitizing devices
A digital camera
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23. How to edit a digital photo
Editing digital photos
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24. Shoes, UFOs, and Forrest Gump
What do you think?
Shoes, UFOs, and Forrest Gump
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 actually took place?
Do you have a set of criteria for judging the authenticity of newspaper and TC images?
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25. 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
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