A/D converter ('ADC'),Analog to digital converter. A device that encodes an analog signal into a series of digital numeric values for processing by a computer. In the case of audio, each value represents the amount of signal present at a particular moment. See also- Sample Rate
Algorithm,The process by which a computer works to solve a particular problem.
Aliasing,Distortion created by the conversion of analog signals into digital form. In audio, the distortion takes the form of unwanted noise and harmonics. In graphic images, a common form of aliasing is the stairstep edge found on type and diagonal lines, often referred to as the 'jaggies'. Aliasing results from not having enough resolution to cleanly represent media as the human eye and ear expects.
Analog, From the word "analogous," analog refers to data that is represented by a method resembling its original form. For example, an analog phone signal is the essential equivalent of the original voice data entering the phone receiver. Digital data, on the other hand, involves converting the signal to a series of ones and zeros that can be understood by computers.
Anti-Aliasing,Refers to methods used for minimizing the perceived distortion caused by aliasing. In graphics, anti-aliasing uses gradual blends between foreground colors and background colors to minimize the appearance of the 'jaggies'.
ASCII,American Standard Code for Information Exchange. ASCII is a standardized system for encoding characters, numbers, punctuation, and other special symbols into digital form for use in computers.
Backup,Backups are copies of original data, including both software programs and user files, to ensure against losing the originals. Effective backup systems should have the ability to manage large amounts of data that are constantly changing, re-use original data at a later time, restore operation of systems that lose data when they fail, among other capabilities.
Binary,A numbering system that uses only two digits, 0 and 1, for representing all numbers. Binary is used internally in computers because the electrical circuits they are made of adapt well to a dual state (0 implies 'off' or grounded electrical state; 1 implies 'on' or positive electrical state) numbering system. End users rarely have to deal with binary, however, since computer software generally translates these codes into more familiar and convenient terms, such as decimal numbering and standard language character sets (English, Arabic, Japanese, etc.).
Bit,Abbreviation for the amount of data associated with a binary digit. Can have either the value 0 or 1. In performance and capacity terminology, bits are represented by a lower-case 'b' in terms such as Kb (Kilobits) or Mb (Megabits).
Bitmap,A graphic display method where an area of memory is used to represent pixels or groups of pixels on the screen.
Build,The process of revealing elements of a presentation screen such as bullet points or illustrations one at a time to complete the screen. Builds can use different transition techniques and can be triggered either by the user or by the computer. Builds help to focus your audience on the current topic of the presentation by only revealing information as it is discussed in the delivery.
Byte,A binary number consisting of 8 total bits. Can represent numbers from 0 to 255 decimal. In performance and capacity terminology, bytes are represented by an upper-case 'B' in terms such as KB (Kilobytes) or MB (Megabytes).
CD-ROM,Compact-Disc Read-only Memory. A laser-based, removable storage medium for computers that is capable of storing up to 680 megabytes of data. Originally successful as a replacement for phonograph records and audio tapes, CD-ROM has become a standard way of delivering full multimedia content in a world where computers are rapidly becoming a standard audio-visual device in homes and business.
Color Depth, The number of colors displayed by your computer monitor in the current video display mode. Color depth is a function of your video card and the software video driver that is currently running. Typical computers can run monochrome, 16 color, 256 color, 64K and true color (also known as 24-bit color, and has a color depth of 16.7 million).
CPU,Central Processing Unit. This is the central operating component of computers, where programs are executed and data is processed. It is connected by other circuitry to control, input/output (I/O), and data storage devices such as hard drives, modem cards, RAM, ROM, CRTs, keyboards, mice, etc.
CRT,Cathode Ray Tube. Also referred to as monitors or screens, CRTs are a dominant form of display technology used for controlling computers and observing the results. Basically the same technology is used in both computer monitors and television sets.
Cut and Paste,Refers to standard capability of modern computer systems to remove data, and place it in a different location under user control.
DAC,Digital-to-analog converter. This type of circuit accepts a digital data stream and converts it into analog voltages as an output. Used, for example, in converting digital audio data into the voltages that can drive speakers to produce audible sound.
Data Rate,The amount of data flowing through a given data transmission device, usually measured per second. For example, the data rate for a typical doublespin computer CD drive is 300kbs or 300,000 bits per second.
Database,A collection of related computer data that is organized for convenient retrieval according to specific need. Can be something as simple as a collection of data files organized in a directory, or as complex as a large client-server system consisting of multiple computers communicating across networks to provide sophisticated search and access capabilities.
Digital,The composition of numbers, words sounds or pictures on a computer. Digital data is completely composed of a series of ones and zeros.
Digitizing,The process of converting analog signals into digital form (see Sampling, Scanning).
Dithering,The use of varied colors and patterns of dots to create a variety of gray scale or color shades on the computer display.
Event,In presentations, an event is an occurrence either caused by the presenter or the equipment s/he is using. A presenter caused event might be a mouse click or shoving the computer off the table. A computer caused event could be to display an animation when a certain time has passed or to crash during a transition, thus embarrassing the presenter (See Assembly Lecture).
Fractals,A method of describing images that arises out of chaos theory. Fractals are used to create realistic texturing or natural scenery (See Media Acquisition and Creation Exhibit).
Graphics - Bitmap,The representation of an image resulting from the combination of individual pixels. Bitmap graphics are typically used for higher quality pictures and displays. Unlike vector graphics, their size cannot be altered without induced distortion (See Media Acquisition and Creation Exhibit).
Graphics - Vector,The representation or an image or object as the result of a mathematical formula. Vector graphics are superior for graphing and for the drawing of geometrical objects such as squares. Since the computer displays only a mathematical equation, file sizes are typically smaller than bitmaps, and can be easily resized (See media Acquisition and Creation Exhibit).
Jaggies,See aliasing, anti-aliasing.
Memory, Usually refers to a computer's primary storage, such as Random Access Memory (RAM) or Read-only memory (ROM). Memory is used by the computer to hold data and programs that are fed to the Central Processing Unit (CPU).
MIDI,Musical Instrument Digital Interface. A protocol for communication between computers and digitally-controlled musical instruments.
Monochrome,A video display technology in which one background and one foreground color are used to display data or graphics. Monochrome is typically used on older computers or on non-color laptops, although almost all computers can support monochrome video display modes.
Morphing,The process of smoothly transforming one object into another through a series of calculated intermediate transitions. (See Media Acquisition and Creation Exhibit).
Motherboard,The motherboard is the main circuit board in your computer. Motherboards hold the CPU, various circuitry for running the computer and system memory. Motherboards typically also have five or more "slots." These slots are basically sockets that other computer devices can be plugged into such as modems, drive controllers, network cards and video cards.
Multimedia Database,A multimedia database allows you to store and access multimedia files such as sounds, videos or pictures (See Digital Media Management Exhibit).
Multimedia,Multimedia is audio-visual computing. This involves the blending of video, sound, text and graphics to create a richer computer interface.
Object,In presentations, a sound, animation, video, graphic, or text element. An object can be associated with different types of applicable actions. For example, videos, animations, and audio clips can be played, images and text can be moved or manipulated. These actions are triggered by events. For example, a video object might play 10 seconds after the presenter clicks his mouse to bring up a new slide (See Assembly Lecture).
Palette,Typically refers to the specific colors that are available for display by the computer in a given display mode. The palette changes with video display mode, specifically with color depth. In indexed display modes (such as 256-color modes), the palette is controlled by software, and at any one time represents a small fraction of the total colors available through the graphics adapter. Managing palettes in indexed display modes is a complex problem that impacts any multimedia developer. (see Media Acquisition and Creation Exhibit)
Presentations - Electronic,Any presentation that is created on and delivered from computers (See Keynote Lecture).
Presentations - Linear,A presentation in which all slides or screens proceed in a pre-determined order with no variation from beginning to end, other than backward or forward movement.
Presentations - Non-Linear,A presentation in which some type of branching or linking is incorporated to allow flexibility in running the presentation or answering questions (See Content Development Lecture).
Rendering,Creation of a final multimedia element, such as a graphic or video, through computer calculation. An example is 3D animation, in which mathematical models of shape, texture, and lighting are rendered into photorealistic graphic images (See also Wireframe).
Sampling,A method for converting analog signals into digital form. In digital audio, samples are taken many times per second and each is converted into a digital value that is stored in memory. On playback, these samples are converted back into analog signals (See Media Acquisition and Creation Exhibit).
Sample Rate,In sampling, the number of times per second that a sample is taken of an incoming signal (See Media Acquisition and Creation Exhibit).
Sample Size,In sampling, the size of data that is taken with each individual sample, e.g., 8-bit or 16-bit (See Media Acquisition and Creation Exhibit).
Scanner,A device used to digitize a picture or text and convert it into computer form. This is another example of analog to digital conversion. Scanners typically convert anything scanned into a computer bitmapped image although some modern scanners can convert paper text into computer readable text files.
Screen Resolution,The number of pixels on a computer monitor, typically defined as a width by height measurement. Typical screen resolution settings are 640x480, 800x600 or 1024x768.
Storage - Disk,Typically, personal computers store permanent information on rotating disks. Disk storage is typically fixed, as in a hard drive, or removable, as in cartridge drives or floppies. These days, hard disks can store massive amounts of information. This information is written to the disk platter by magnetic read-write heads. Unlike RAM memory, this information is retained even when the power is shut off.
Storyboard,Storyboards are rough picture and text outlines of a concept that will be later executed in print, graphics, audio or video. A typical storyboard might have sketched picture frames along the left-hand column while the right-hand column has text or scripts for the particular sequence. By using storyboards, presenters and multimedia producers can portray ideas inexpensively before executing in a more expensive media (see Content Development Lecture).
SVGA,Super Variable Graphics Array - A DOS and Windows-based display standard that supports larger palettes and screen resolutions than VGA.
Transition,In presentations a transition is the method used to display new screens, pictures or text information. Transitions can be used to add sizzle to your presentation. All current computer-based presentation packages include some transitions. Typical transition styles include fades, wipes, fly in and blinds.
Upstaging,The act of imposing something between the audience and the presenter or the presentation screen. A presenter can upstage her presentation by walking in front of the presentation screen while talking. She may also upstage herself by placing part of her body between the audience and her face. Placing one's foot in one's mouth is a typical example of upstaging (See Delivery Lecture).
VGA,Variable Graphics Array - A widely-adopted, outdated DOS and Windows-based hardware/software standard for computer displays. The most commonly used video display modes associated with VGA are 16 colors at a screen resolution of 640X480, and 256 colors at 320x240.
Video Driver,The software used to display information or graphics on the computer screen. Actual display capabilities are a combination of the monitor, the video board and the video driver. It is the video driver that is used to switch both color depth and screen resolution. Some video drivers can also accelerate the display of graphics. Windows comes with several standard video drivers including ones for VGA and SVGA. Add-on video boards usually come with their own custom video drivers.
Wireframe,A skeletal model used to define a two or three dimensional set of objects and environments on the computer, typically to be rendered into final form by the computer. In 3d animation, for example, graphic scenes and objects are built and viewed in wireframes before detail such as colors, textures, and lighting are added (See Media Acquisition and Creation Exhibit).
