Chapter 6

Graphics, Digital Media, and Multimedia 

Tim Berners-Lee Weaves the Web for Everybody

Born in London in 1955

Wanted to create an open-ended distributed hypertext system with no boundaries, so scientists everywhere could link their work together 

Invented the World Wide Web and gave it to all

 Now works at MIT

Heads the World Wide Web Consortium (W3C) 

Painting: Bitmapped Graphics

 Painting software:

 Paints pixels on the screen with a

                pointing device

Pointer movements are translated

                into lines and patterns on the screen

Stores an image at 300

                dots per inch or higher

 Pixels: tiny dots of white, black, or color that make up images on the screen

 Palette of tools mimics real-world painting tools

Ø  Also contains other tools that are unique to computers

Bitmapped graphics (or raster graphics): pictures that show how the pixels are mapped on the screen

Color depth: the number of bits devoted to each pixel

Resolution: the density of the pixels

Digital photo management software programs such as Apple iPhoto and Microsoft PictureIt! simplify and automate common tasks associated with capturing, organizing, editing, and sharing digital images.

PostScript: a standard page-description language for describing text fonts, illustrations, and other elements of the printed page

> Used by professional drawing programs such as Adobe Illustrator and Macromedia FreeHand

> Built into many laser printers and other high-end output devices so those devices can understand and follow PostScript instructions

> PostScript-based drawing software constructs a PostScript program as the user draws

Bit-mapped painting (pixels) gives you these advantages:

> More control over textures, shading, and fine detail

> Appropriate for screen displays, simulating natural paint media, and embellishing photographs

Some integrated programs contain both drawing and painting modules

>  Allows you to choose the right tool for each job

Some programs merge features of both in a single application

>  Blurs the distinction between types

>  Offers new possibilities for amateur and professional illustrators

3-D Modeling Software

>>  Used to create three-dimensional objects with tools similar to those in drawing software

>>  Goal for some applications: to create an animated presentation on a computer screen or videotape

>>  Flexible: can create a 3-D model, rotate it, view it from different angles

>>  Can “walk-through” a 3-D environment that exists only in the computer’s memory

CAD/CAM: Turning Pictures into Products

 Computer Aided Design (CAD) software

Allows engineers, designers, and architects to create

                designs on screen for products ranging from computer

                chips to public buildings 

Can test product prototypes

 Cheaper, faster, and more accurate than traditional

                design-by-hand techniques

Computer-Aided Manufacturing (CAM) is the process by which data related to the product design are fed into a program that controls the manufacturing of parts.

Computer-Integrated Manufacturing (CIM) refers to the combination of CAD/CAM and is a major step toward a fully automated factory.

Dynamic Media: Beyond the Printed Page

  Modern media contains dynamic information, which is information that changes over time or in response to user input.

1. Animation

2. Desktop Video

3. Audio

4. Hypertext and hypermedia

Animation: Graphics in Time

 Each frame of  computer-based

                animation is a computer-drawn picture;

                the computer displays these

                frames in rapid succession.

 Tweening: Instead of drawing each frame

                by hand, the animator can create key frames

                and objects and use software to help fill

                in the gaps.

The Synthetic Musician: Computers and Audio

 Audio digitizer – captures sound and stores it as a data file

Synthesizer – an electronic instrument that

                synthesizes sounds using mathematical

                formulas

 MIDI (Musical Instrument Digital

                Interface) – standard interface that allows

                electronic instruments and computers to communicate with each other

Music is digitized on audio CDs at a high sampling rate and bit depth—high enough that it’s hard to tell the difference between the original analog sound and the final digital recording.

WAV, AIFF = Standard formats for uncompressed audio for Windows and the Mac OS, respectively. Both formats are supported on Windows, Mac OS, and Linux. Both create large files. Both are lossless – a CD track encoded with  WAV or AIFF sounds identical to the original.

MP3 = A popular format for transmitting audio on the Internet. A CD track converted to MP3 format can be 1/10 the size of the original – or smaller – but still sound very similar.

WMA = An alternative to MP3 developed by Microsoft for Windows. WMA compression can result in smaller files of higher fidelity. WMA files may be protected by DRM. 

AAC = Apple’s alternative to MP3 and WMA is used primarily by iTunes and iTunes Music Store. AAC compression is sonically superior to MP3 compression. AAC files may be protected by DRM.

OGG = Similar to WMA and AAC in sound quality and compression, OGG Vorbis is open source and freely available – not controlled by any company.

Hypertext refers to information linked in non-sequential ways.

Hypermedia combines text, numbers, graphics, animation, sound effects, music, and other media in hyperlinked documents.

>> Useful for on-line help files

>> Lets the user jump between documents all over the Internet

Computer graphics today encompass more than quantitative charts and graphs generated by spreadsheets.

Computers today aren’t limited to working with static images; they’re widely used to create and edit documents in media that change over time or in response to user interaction.

The interactive nature of the personal computer makes it possible to create nonlinear documents that Today we can create or explore hypermedia documents—interactive documents that mix text, graphics, sounds, and moving images with onscreen navigation buttons—on disk and on the World Wide Web.

Multimedia computer systems make a new kind of software possible—software that uses text, graphics, animation, video, music, voice, and sound effects to communicate.

Regardless of the hardware, interactive multimedia software enables the user to control the presentation rather than just watch or listen passively.

enable users to take individual paths through information.

~ooo~