Gl'ap Ics Basics
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Gl'ap ics Basics What Is a Graphic? In day-to-day speech, people use the word graphic to refer to any visual image or object: A family photo, a road map, and a stick figure drawn on a chalkboard are all examples of graphics. When people talk about a computer graphic, they usually are referring to an image. Images include draw ings, painted backgrounds, and photographs. Com puter graphics can be displayed in a variety of ways. They can appear on the screen as a background, or they can be placed into a document to add color and infor mation. Thus, in the broadest sense of the term, computer graphic could refer to anything that can be seen on the computer screen. ' ~ Chapter Outline What's Online '" ,· ~lwww . PHSuccessNet.com,._.:.J ~Go ~ Lesson 9-1 ,., Interactive tutorials Graphics and Their ,., Vocabulary Preview worksheet Uses ,., Learn More interactivities Check Your Understanding Lesson 9-2 instant feedback assessment Exploring Graphics ,., Check Your Knowledge Programs instant feedback assessment ,., Interdisciplinary practice Lesson 9-3 activities Working With ,,, Interdisciplinary application Graphics activities Graphics Basics • 123 Graphics and Their Uses Objectives As You Read What's Online • Identify two diffe·rent types Compare and Contrast As you In Lesson 9-1 online, you will of graphics and explain the read this lesson, use a Venn dia find more features and informa differences between them. gram to show the similarities tion for this lesson, including: and differences between bit • List the advantages of each mapped graphics and vector • Interactive tutorials type of graphic. graphics. • As You Read worksheet • Differentiate between draw • Learn More interactivities and paint programs. • Check Your Understanding interactive assessments • Interactive lesson review ~ Key Terms Types of Graphics • graphic (p. 123) There are hundreds of different uses for computer graphics. • bitmapped graphic However, graphics fall into only two categories: (p. 124) • bitmapped graphics • pixel (p. 124) • vector graphics • vector graphic (p. 125) Bitmapped Graphics A bitmapped graphic, or bitmap, is an • resolution (p. 125) image formed by a pattern of dots. Imagine a sheet of graph • paint program (p. 126) paper with each of its squares filled in with a certain color to • draw program (p. 126) make a picture. If seen from far enough away, the picture will • image editor (p. 126) look clear, and the squares won't be noticed. But up close, you can see the individual squares of the graph paper. Bitmapped graphics are composed of tiny dots of different colors. Each single point in the image is a pixel, short for "pic ture element." The smaller the pixels in the image, the smoother it will look. The more colors in the image, the brighter and sharper the image will look. Some common bitmapped file formats include: • Graphics Interchange Format (GIF) •Joint Photographic Experts Group (JPG) • Portable Network Graphics (PNC) • Windows Bitmap (BMP) Some formats are used for images on Web pages, while others are used for icons and images in the operating system. These same abbreviations are used as the file extensions. A file ending in .gif, for example, is in the GIF file format. Bitmaps are preferred for some types of images. They often are used for photos or images that require backgrounds. 124 • Chapter 9 Vector Graphics A vector graphic is an image that is created using paths or lines. A vector image tells the computer where a line starts and where it ends. It allows the computer to figure out how to connect the two points. The lines can form shapes, which may be filled with a color or pattern. Students in different countries Encapsulated PostScript, or EPS, is one of several formats e-mail pictures from their every commonly used for vector art. EPS files contain the information day lives to one another. The pic that a printer needs in order to print a graphic correctly. The tures help students understand information is combined with a small sketch of what the what life is like in a different graphic should look like. The sketch inside an EPS file allows culture. you to preview an image on-screen. This way, you can be sure Think About It! the image is correct before printing it. Circle the number that correctly shows the number of pixels in a 1 Size, Resolution, and Dots Per Inch inch by 1 inch picture at 150 dpi. Two basic qualities affect how every bitmapped image will ,,,,. 2,500 pixels appear. Size, the height and width of the graphic, is normally ,,,,. 10,000 pixels measured either in pixels or in inches. Resolution tells how ,,,,. 22,500 pixels many pixels are in a certain piece of an image. Resolution also determines the quality of the computer image. Resolution is usually measured in dots per inch, or dpi. An image that is 1 inch square at 72 dpi will contain a total of 5,184 pixels (72 x 72). Generally, the higher the resolution, the sharper the image will look. Vector graphics are created using lines or paths rather than pixels. Thus, the number of dots per inch is not a concern when Figure 9.1.1 When viewed changing the size of vector graphics. If a bitmapped image is on the screen , vector graphics enlarged to twice its normal size, it will look fuzzy and jagged. look sharper than bitmapped A vector image can be enlarged to any size and keep its quality. graphics. Vector Graphic Bitmapped Graphic 1000% Magnification ...... c: c:~ .!2 8::I ""Cl LU c: 0 ~ ~ I ~ I @ Enlarged vector graphic Enlarged bitmapped graphic Graphics Basics • 125 Graphics Programs Different programs allow you to create, edit, and view different graphic file types. Choosing the right program depends on which type of graphic you are working with and what your Multimedia designers develop Web needs are. sites and CDs using some of the same programs you use. Their Paint Programs A paint program allows you to create a new jobs vary, but they often create bitmapped image. Paint programs also allow you to open a bit images for programs. mapped image, view it on-screen, and make changes to it. Think About It! Draw Programs A program that allows you to create and edit Using the right design program is vector images is called a draw program. Since draw programs important for designers. Consider focus on vector images, they make editing easy. You can change the following tasks. Circle those the size of an image or add color to it. that need to be completed by a Basic draw programs, such as the one in Microsoft Word, draw program. allow you to perform simple drawing tasks. More complex pro ,,, view a bitmapped image grams, such as Adobe®Illustrator ®and CorelDRAW®, allow you to do more but require more time to learn. ,,, add color to a vector image ,,, add effects to a bitmapped Image Editors An advanced paint program is called an image image editor. Image editors are designed for editing bitmapped ,,, change the size of a vector images. They are also often used for adding special effects to image photographs. Adobe®Photoshop ® and Adobe®Photodelux ®are examples of popular image editors. After final drawings or clay models of the characters were approved, 3-D mod PIXAR STUDIOS els were designed on computers. Next, You may have never heard the designers considered movements and name Pixar, but you've prob expressions. They looked at photos of live ably heard of their animated actors in various positions and with dif films. Toy Story and Monsters, ferent expressions to get an idea Inc. are just two examples of of how each figure should move. their work. These films were Animators then used created using computers. Pixar's animation soft Pixar films are known for ware to their realistic cartoon charac make the ters. Some aspects of creating images these characters involved tech come to life nology similar to the draw and with movements paint programs and image edi and expressions. tors discussed in this lesson. 126 • Chapter 9 t Demonstrate Your Knowled e Critical Thinking 1. How do bitmapped graphics and vector graphics differ? 2. If you want to enlarge a graphic to three times its size, should you start with a bitmapped or a vector image? Why? Activities 1. Complete the following spider map showing the functions of paint programs, draw programs, and image editors. Paint programs 1. 2. Functions 3. of Graphics Image editors 4. Programs 1. 2. Draw programs 1 . -=..... c~ 2 . ' c:> I ·s :::> 3. I :E c ! ~ ~4·~~~~~~~~- 1 c i ~ @ 2. Research a company that works with graphics. Find out what types of graphics they use, the programs they use, and what they do With the images. Write a one-page report that details your findings. Graphics Basics • 127 Exploring Graphics Programs Objectives As You Read What's Online • Identify the mairi sections Summarize Information Make In Lesson 9-2 online, you will of a graphics application a table that lists tools used in find more features and informa window. paint and draw programs on the tion for this lesson, including: left. On the right, include the • List the different tools type of program(s) each tool is • Interactive tutorials available in paint and used in. • As You Read worksheet draw programs. • Learn More interactivities • Determine when to use the tools in a paint or • Check Your Understanding draw program. interactive assessments • Interactive lesson review ~ Key Terms Exploring the Application Window • workspace (p. 128) Paint and draw programs vary from one to another, but most • color palette (p. 128) include a workspace, toolbars, and color palettes. • Eyedropper (p.