Chapter 3 - Graphics PDF

Chapter 3 : Graphics © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Overview Creation of multimedia images Creation of still images Colors and palettes in multimedia Image file types used in multimedia © 2011 The McGraw-Hill Companies, Inc. All rights...

Chapter 3 : Graphics © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Overview Creation of multimedia images Creation of still images Colors and palettes in multimedia Image file types used in multimedia © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Multimedia Images Before commencing the creation of images in Multimedia, you should: – Plan your approach using flow charts and storyboards. – Organize the available tools. – Have multiple monitors, if possible, for lots of screen real estate. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images Still images may be the most important element of a multimedia project. The type of still images created depends on the display resolution, and hardware and software capabilities. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Types of still images 3-D drawing and rendering © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Still images are generated in two ways: – Bitmaps – Vector-drawn graphics © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Bitmaps – Bitmap is derived from the words “bit,” which means the simplest element in which only two digits are used, and “map,” which is a two- dimensional matrix of these bits. – A bitmap is a data matrix describing the individual dots of an image. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) 1-bit or 2 color displays © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Bitmaps are an image format suited for creation of: – Photo-realistic images – Complex drawings – Images that require fine detail © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Bitmaps – Bitmapped images are known as paint graphics. – A bitmap is made up of individual dots or picture elements known as pixels or pels. – Bitmapped images can have varying bit and color depths. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) 24 bits depth. Dithered to 8 bits. Dithered to 8 bits. Dithered to 4 bits. Millions of colors. Adaptive palette Macintosh palette 16 colors. of 256 colors. of 256 colors. Available binary Combinations for Describing a Color Dithered to 8-bit Dithered to 4-bit Dithered to 1-bit. gray-scale. gray-scale. Two colors, black 256 shades of gray. 16 shades of gray. and white. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Bitmaps can be inserted by: – Using clip art galleries – Using bitmap software – Capturing and editing images – Scanning images © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Using clip art galleries – A clip art gallery is an assortment of graphics, photographs, sound, and video. – Clip art is a popular alternative for users who do not want to create their own images. – Clip art collections are available on CD-ROMs and on the Internet. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Using clip art galleries A page of thumbnails showing the content of various royalty-free Photodisc collections from Getty Images © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) The industry-standard programs for bitmap painting and editing are: – Adobe’s Photoshop and Illustrator. – Corel’s Painter and CorelDraw. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Capturing and editing images – Capturing and storing images directly from the screen is another way to assemble images for multimedia. – The PRINT SCREEN key in Windows or the COMMAND- SHIFT-4 key combination on the Macintosh copies the screen image to the clipboard. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Image editing programs enable the user to: – Enhance and make composite images. – Alter and distort images. – Add and delete elements. – Morph (manipulate still images to create animated transformations). © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Morphing software was used to seamlessly transform the images of 16 kindergartners. When a sound track of music and voices was added to the four-minute piece, it made a compelling video about how similar children are to each other. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Users can scan images from conventional sources and make necessary alterations and manipulations. Exposure from Alien Skin allows users to manipulate bitmapped images. Here a digital color image has been processed to look like it came from a darkroom. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Vector-drawn graphics – Applications of vector-drawn images – How vector-drawn images work – Vector-drawn images versus bitmaps © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Vector-drawn images are used in the following areas: – Computer-aided design (CAD) programs – Graphic artists designing for the print media – 3-D animation programs – Applications requiring drawing of graphic shapes © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Drawing software such as Adobe Illustrator can save vector graphics in SVG format. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) How vector-drawn images work – A vector is a line that is described by the location of its two endpoints. – Vector drawing makes use of Cartesian coordinates. – Cartesian coordinates are numbers that describe a point in two- or three-dimensional space as the intersection of the X, Y, and Z axes. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) How vector-drawn images work Creating scalable vector graphics (svg) file © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Vector-drawn images versus bitmaps – Vector images use less memory space and have a smaller file size as compared to bitmaps. – For the Web, pages that use vector graphics in plug-ins download faster and, when used for animation, draw faster than bitmaps. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Vector-drawn images versus bitmaps (continued) – Vector images cannot be used for photorealistic images. – Vector images require a plug-in for Web-based display. – Bitmaps are not easily scalable and resizable. – Bitmaps can be converted to vector images using autotracing. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) 3-D drawing and rendering – 3-D animation tools – Features of a 3-D application – Panoramas © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) 3-D animation, drawing, and rendering tools include: – Daz3D – Form*Z – NewTek′s Lightwave – Autodesk’s Maya 3-D applications provide x, y, and z axes and adjustable perspective views. – Google’s SketchUp © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Features of a 3-D application – Modeling - Placing all the elements into 3-D space. – Extrusion - The shape of a plane surface extends some distance. – Lathing - A profile of the shape is rotated around a defined axis. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Rendering - Use of intricate algorithms to apply user-specified effects © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Panoramas – Panoramic images are created by stitching together a sequence of photos around a circle and adjusting them into a single seamless bitmap. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia Understanding natural light and color Color palettes Color pickers allow you to select a color using one or more different models of color space. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (continued) Understanding natural light and color – Light comes from an atom where an electron passes from a higher to a lower energy level. – Each atom produces uniquely specific colors. – Color is the frequency of a light wave within the narrow band of the electromagnetic spectrum, to which the human eye responds. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (continued) Understanding natural light and color (continued) – Additive color – Subtractive color – Monitor-specific color – Color models © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (continued) Additive color – In the additive color method, a color is created by combining colored light sources in three primary colors - red, green, and blue (RGB). – TV and computer monitors use this method. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (continued) Subtractive color – In the subtractive color method, color is created by combining colored media such as paints or ink. – The colored media absorb (or subtract) some parts of the color spectrum of light and reflect the others back to the eye. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (continued) Subtractive color (continued) – Subtractive color is the process used to create color in printing. – The printed page consists of tiny halftone dots of three primary colors: cyan, magenta, and yellow (CMY). © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (continued) Monitor-specific colors – Colors should be used according to the target audience’s monitor specifications. – The preferred monitor resolution is 800 x 600 pixels. – The preferred color depth is 32 bits. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (continued) Models used to specify color in computer terms are: – RGB model – A 24-bit methodology: color is specified in terms of red, green, and blue values ranging from 0 to 255. – HSB and HSL models – Color is specified as an angle from 0 to 360 degrees on a color wheel. – Other models include CMYK, CIE, YIQ, YUV, and YCC. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (continued) Color palettes – Palettes are mathematical tables that define the color of pixels displayed on the screen. – Palettes are called “color lookup tables,” or CLUTs, on the Macintosh. – The most common palettes are 1, 4, 8, 16, and 24-bit deep. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (continued) Dithering: – Dithering is a process whereby the color value of each pixel is changed to the closest matching color value in the target palette. – This is done using a mathematical algorithm. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (continued) Dithering These images were dithered in Photoshop to best fit the 8-bit palettes of GIF files (Adaptive, System, or Custom 216 Netscape). Also shown are JPEG files compressed with highest and lowest quality and their actual file sizes. Note the subtle differences among palettes and systems, especially in the gradient blue background. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Image File Types Used in Multimedia Macintosh formats Windows formats Cross-platform formats © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Image File Types Used in Multimedia (continued) Macintosh formats – On the Macintosh, the most commonly used format is PICT. – PICT is a complicated and versatile format developed by Apple. – Almost every image application on the Macintosh can import or export PICT files. – In a PICT file, both vector-drawn objects and bitmaps can reside side-by-side. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Image File Types Used in Multimedia (continued) Windows formats – The most commonly used image file format on Windows is DIB, also known as BMP. DIB stands for device-independent bitmaps. – Bitmap formats used most often by Windows developers are: BMP - A Windows bitmap file TIFF - Extensively used in DTP packages PCX - Used by MS-DOS paint software © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Image File Types Used in Multimedia (continued) Cross-platform formats – JPEG, GIF, and PNG – Most commonly used format on the Web – Adobe PDF (Portable Document Format) – Manages multimedia content – PSD, AI, CDR, DXF – Proprietary formats used by applications – Initial Graphics Exchange Standard (IGS or IGES) –Standard for transferring CAD drawings © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Summary The computer generates still images as bitmaps and vector-drawn images. Images can be incorporated in multimedia using clip art or bitmap software, or by capturing, editing, or scanning images. Creating 3-D images involves modeling, extruding, lathing, shading, and rendering. Color is one of the most vital components of multimedia. © 2011 The McGraw-Hill Companies, Inc. All rights reserved