CS10001 Class Note: Chapter 6 Productivity Applications
Objectives
Ø Explain the difference between painting software, image processing software, drawing software, and 3-D modeling software
Ø Explain effective techniques for improving the quality of slides prepared with presentation software
Ø Explain the difference between analog video and digital video
Ø Describe how data compression works
Ø Describe several present and future applications for multimedia technology
Tim Berners-Lee Weaves the Web for Everybody
Ø Tim Berners-Lee
q Born in London in 1955
q Wanted to create an open-ended distributed hypertext system with no boundaries, so scientists everywhere could link their work together
q Invented the World Wide Web and gave to all
q Now works at MIT
q Heads the World Wide Web Consortium (W3C)
Focus on Computer Graphics
Ø Pixels: tiny dots of white, black, or color that make up images on the screen
Ø Painting software:
q Paints pixels on the screen with a pointing device
q Pointer movements are translated into lines and patterns on the screen
q Stores an image at 300 dots per inch or higher
Ø Palette of tools mimics real-world painting tools
q Also contains other tools that are unique to computers
Ø Bitmapped graphics (or raster graphics): pictures that show how the pixels are mapped on the screen
Ø Gray-scale graphics: uses 8 bits per pixel and allows up to 256 shades of gray, including white and black
Ø Color depth: the number of bits devoted to each pixel
Ø Resolution: the density of the pixels; described as dpi (dots per inch)
Ø Image processing: photographic editing by computer
q Allows the user to manipulate photographs and other high-resolution images with tools such as Adobe Photoshop
q Far more powerful than traditional photo-retouching techniques
· Can distort and combine photos as demonstrated in the tabloids
· Can create fabricated images that show no evidence of tampering
q 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.
Ø Drawing: object-oriented graphics
q Drawing software stores a picture as a collection of lines and shapes (called object-oriented or vector graphics).
q Memory demands on storage are not as high as for bit-mapped images.
q Many drawing tools–line, shape, and text tools–are similar to painting tools in bitmapped programs.
q PDF (portable document format): a file format developed by Adobe that enables digital documents to be exchanged between programs independent of application software, hardware, or operating system.
· Can contain text, fonts, images, and vector graphics
· Can be displayed by Web browsers
q 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
q Object-oriented drawing gives you these advantages:
· Better for creating printed graphs, charts, and illustrations
· Lines are cleaner and shapes are smoother
q Some integrated programs contain both drawing and painting modules
· Allows you to choose the right tool for each job
q Some programs merge features of both in a single application
· Blurs the distinction between types
· Offers new possibilities for amateur and professional illustrators
Ø Rules of thumb: creating smart art
q Reprogram yourself . . . relax.
q Choose the right tool for the job
q Borrow from the best
q Don’t borrow without permission
q Protect your own work
· U.S. Copyright Office Web Site: http://lcweb.loc.gov/copyright/
Ø 3-D modeling software
q Used to create three-dimensional objects with tools similar to those in drawing software
q Goal for some applications: to create an animated presentation on a computer screen or videotape
q Flexible: can create a 3-D model, rotate it, view it from different angles
q Can “walk-through” a 3-D environment that exists only in the computer’s memory
Ø CAD/CAM: Turning pictures into products
q CAD (computer aided design) 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
q CAM (computer-aided manufacturing) is the process by which data related to the product design are fed into a program that controls the manufacturing of parts.
Ø CIM (computer-integrated manufacturing) refers to the combination of CAD/CAM and is a major step toward a fully automated factory.
Ø Presentation graphics: bringing lectures to life
q Automates the creation of visual aids for lectures, training sessions, sales demonstrations, and other presentations
q Creates slideshows directly on computer monitors or LCD projectors, including still images, animation, and video clips
Ø Rules of thumb: making powerful presentations
q Remember your goal
q Remember your audience
q Outline your ideas
q Be stingy with words
q Keep it simple
q Use a consistent design
q Cool colors make better backgrounds
q Use large letters
q Be smart with art
q Keep each slide focused
q When presenting:
· Stand to the left of the screen
· Do not read the slides
· Pause when you reveal a new slide or bullet
· Vary your pace or volume to make a point
Dynamic Media: Beyond the Printed Page
Ø Modern media contains dynamic information, which is information that changes over time or in response to user input.
q Animation
q Desktop video
q Audio
q Hypertext and hypermedia
Ø Animation: graphics in time
q Each frame of computer-based animation is a computer-drawn picture; the computer displays these frames in rapid succession.
q 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.
Ø Desktop video: computers, film, and TV
q Analog and digital video
· A video digitizer can convert analog video signals from a television broadcast or videotape into digital data.
q Many video digitizers can import signals from televisions, videotapes, video cameras, and other sources.
· Signals are displayed on the computer’s screen in real time—at the same time they’re created or imported.
q Digital video cameras capture footage in digital form.
q Digital video can be copied, edited, stored, and played back without any loss of quality.
q Digital video will soon replace analog video for most applications.
Ø Video production goes digital
q Storyboard describes the action, dialogue, and music in each scene
q Today most video editing is done using nonlinear editing technology.
q Video editing software, such as Adobe Premiere, makes it easy to eliminate extraneous footage, combine clips from multiple takes, splice together scenes, create specific effects, and perform a variety of other activities.
q Morphs are video clips in which one image metamorphoses into another.
q Data compression software and hardware are used to squeeze data out of movies so that they can be stored in smaller spaces.
Ø Data compression
q Saves storage space
q Allows the processor to keep up with the quickly changing frames
q Image-compression software: compresses graphics and video files
Ø The synthetic musician: computers and audio
q Sound data is sometimes called waveform audio
· Recorded sound can consume massive amounts of space on disk and in memory.
· The difference is due in part to differences in sampling rate–the number of sound “snapshots” the recording equipment takes each second.
q A higher sampling rate produces more realistic digital sound in the same way that higher resolution produces more realistic digital
q Audio digitizer–captures sound and stores it as a data file
q Synthesizer–an electronic instrument that synthesizes sounds using mathematical formulas
q MIDI (musical instrument digital interface)–standard interface that allows electronic instruments and computers to communicate with each other
q 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
q Online P2P (peer-to-peer) file sharing services such as Napster popularized the illegal sharing of stolen music. Still, there are many online sources for legally downloading music files using AAC and WMA formats.
Popular Digital Audio Formats
Format / DescriptionWAV, 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.
Ø Samplers, synthesizers, and sequencers: digital audio and MIDI
q Multimedia computers can control a variety of electronic musical instruments and sound sources using MIDI.
q MIDI commands can be interpreted by a variety of:
· Music synthesizers
· Samplers
q A piano-style keyboard sends MIDI signals to the computer. Computer interprets the
MIDI commands using sequencing software.
q Sequencing software: turns a computer into musical composing, recording, and editing machine.
q Virtual instruments: instruments that exist only in software
q Electronica: music designed from the ground up with digital technology
Ø Rule of thumb: digital audio do’s and don’ts
q Don’t steal
q Understand streaming and downloading
q Know your file formats
q Don’t over-compress
Ø Hypertext and hypermedia
q Hypertext refers to information linked in non-sequential ways.
q Hypermedia combines text, numbers, graphics, animation, sound effects, music, and other media in hyperlinked documents.
· Useful for online help files
· Enables the user jump between documents all over the Internet
Hypertext and Hypermedia
Ø Hypermedia documents can be disorienting and leave readers wondering what they’ve missed.
q Documents don’t always have the links readers want.
q Authors can’t build every possible connection into documents.
q Some readers get frustrated because they can’t easily get “here” from “there.”
Ø Documents sometimes contain “lost” links, especially on the Web, where even a popular page can disappear.
Ø Documents don’t encourage scribbled margin notes, highlighting, or turned page corners for marking key passages.
Ø Hardware can be hard on humans.
Ø The art of hypermedia is still in its infancy.
Interactive Multimedia: Eye, Ear, Hand, and Mind
Ø Interactive multimedia: what is it?
q A combination of text, graphics, animation, video, music, voice, and sound effects that allows the user to take an active part in the experience
q Requirements: high-quality color monitors, fast processors, large memory, CD–ROM drives, speakers, and sound cards
Multimedia Authoring: Making Mixed Media
Ø Uses authoring programs such as HyperStudio and MetaCard
Ø Binds source documents together to communicate with users in an aesthetically pleasing way
Ø Interactive media: visions of the future
q Offers hope that communication may become participatory again
q Some still fear interactive media will make it possible to be further removed from society
Ø Rules of thumb: making interactive multimedia work
q Be consistent in visual appearance
q Use graphical metaphors to guide viewers
q Keep the screen clean and uncluttered
q Include multimedia elements to enliven the presentation
q Focus on the message
q Give the user control
q Test your presentation with those unfamiliar with the subject
Ø Inventing the future: shared virtual spaces
q Virtual reality combines virtual worlds with networking.
· It places multiple participants in a virtual space.
· People see representations of each other, sometimes called avatars.
· Most avatars today are cartoonish, but they convey a sense of presence and emotion.
q Tele-immersion:
· Uses multiple cameras and high-speed networks to create a videoconferencing environment in which multiple-remote users can interact with each other and with computer-generated objects
· Combines the display and interaction techniques of virtual reality with new vision technologies that allow participants to move around in shared virtual spaces, all the while maintaining their unique points of view
q AR (augmented reality):
· The use of computer displays that add virtual information to a person’s sensory perceptions
Lesson Summary
Ø Computer graphics today encompass more than quantitative charts and graphs generated by spreadsheets.
Ø 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.
Ø The interactive nature of the personal computer makes it possible to create nonlinear documents that enable users to take individual paths through information.
Ø Today we can create or explore hypermedia documents—interactive documents that mix text, graphics, sounds, and moving images with on-screen navigation buttons—on disk and on the World Wide Web.
Ø Multimedia computer systems make a new kind of software possible—software that uses text, graphics, animation, video, music, voice, and sound effects to communicate.
Ø Regardless of the hardware, interactive multimedia software enables the user to control the presentation rather than just watch or listen passively.