Data Systems - University of Texas at Arlington (UTA) - Exam 1 - Units 1, 2, and 3

Data

In the context of computing and data management, the symbols that a computer uses to represent facts and ideas.

Data Representation

The use of electronic signals, marks, or binary digits to represent character, numeric, visual, or audio data.

Digital Data

Text, numbers, graphics, or sound represented by discrete digits, such as 1s and 0s.

Analog Data

Data that is measured or represented on a continuously varying scale, such as a dimmer switch or a watch with a sweep second hand.

Binary

The representation of data using two states, such as off-on or 1-0.

Digitization

Converting non-digital information or media to a digital format through the use of a scanner, sampler, or other input device.

Bit

The smallest unit of information handled by a computer. A bit is one of two values, either a 0 or a 1. Eight bits constitute a byte, which can represent a letter or a number.

File

A named collection of data (such as a computer program, document, or graphic) that exists on a storage medium, such as a hard disk or flash drive.

File Name Extension

The characters in a file name after the period, such as .exe and .txt.

File Format

The method of organization used to encode and store data in a computer. Text formats include DOCX and TXT. Graphics formats include BMP, TIFF, GIF, and PNG.

Numeric Data

Numbers that represent quantities and can be used in arithmetic operations.

Binary Number System

A method for representing numbers using only two digits: 0 and 1. Contrast to the decimal number system, which uses ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.

Character Data

Letters, symbols, or numerals that will not be used in arithmetic operations (name, Social Security number, etc.).

ASCII (American Standard Code for Information Interchange)

A code that represents characters as a series of 1s and 0s. Most computers use ASCII code to represent text, making it possible to transfer data between computers.

Extended ASCII

Similar to ASCII but with 8-bit character representation instead of 7-bit, allowing for an additional 128 characters.

Unicode

A 16-bit character-representation code that can represent more than 65,000 characters.

UTF-8

A variable-length coding scheme that uses seven bits for common ASCII characters, but uses 16-bit Unicode as necessary.

ASCII Text

Text files that contain no embedded formatting codes.

Delimiter

A special character used to separate commands or formatting characters from the rest of the text in a file.

OCR (Optical Character Recognition)

The ability of a device or software to digitize text from printed sources.

Byte

An 8-bit unit of data that represents a single character.

Kilobit

1,024 bits

Kilobyte

1,024 bytes

Megabit

1,048,576 bits

Megabyte

1,048,576 bytes

Gigabit

2^(30) bits

Gigabyte

2^(30) bytes

Data Compression

The process of shrinking the size of a file by removing data or recoding it more efficiently.

Lossless Compression

A compression technique that is able to reconstitute all of the data in the original file; hence, lossless means that this compression technique does not lose data.

Lossy Compression

Any data compression technique in which some of the data is sacrificed to obtain more compression.

Digital Audio

Music or voice that has been digitized into files using sampling techniques; sometimes referred to as waveform audio.

Analog-to-Digital Converter

Any device, such as a sound card, that converts analog data into digital data.

Digital-to-Analog Converter

A device that converts digital data, such as 1s and 0s, in an audio file into continuous data, such as audio sounds.

Sampling Rate

The number of times per second a sound is measured during the recording process.

Audio Compression

Techniques used to reduce the size of files that contain audio data.

AAC (Advanced Audio Coding)

A file format that provides highly compressed audio files with very little loss of sound quality and is promoted by Apple on its iTunes Web site.

MP3

A file format that provides highly compressed audio files with very little loss of sound quality.

Ogg Vorbis

An audio file format with the .ogg extension, used by Spotify. Failed to catch on as a popular standard.

WAV

An audio file format with the .wav extension that was the original “native” sound format for Windows.

AAX (Audible Enhanced Audio)

A popular digital audio format used by Amazon to distribute audio books.

WMA (Windows Media Audio)

A file format with the .wma extension that is promoted by Microsoft and provides highly compressed audio files with very little loss of sound quality.

Audio Interface

The hardware and software that accept input from a microphone and feed it into a digital device.

Digital Audio Extraction

The process of copying files from an audio CD and converting them into a format that can be stored and accessed from a computer storage device, such as a hard disk; sometimes referred to as ripping.

Download

The process of transferring a copy of a file from a remote computer to a local computer’s storage device.

Live-Stream

Streaming data that carries an event happening in real time.

On-Demand Stream

Streaming media that starts and stops when requested, as opposed to a live stream.

Copy Protection

The use of various technologies by music and video distributors to curtail unauthorized copying.

Digital Rights Management

The use of various technologies by music and video distributors to curtail unauthorized copying.

Synthesized Sound

Artificially created sound, usually found in MIDI music or synthesized speech.

MIDI (Musical Instrument Digital Interface)

A standardized way in which sound and music are encoded and transmitted between digital devices that play music.

MIDI Messages

The commands that create MIDI music by specifying the note to play, its duration, and the instrument that plays it.

Speech Synthesis

The process by which computers produce sound that resembles spoken words.

Speech Recognition

The process by which computers recognize voice patterns and words, and then convert them to digital data.

Phoneme

A unit of sound that is a basic component of words and is produced by speech synthesizers.

Text-to-Speech Software

Software that generates speech based on written text that is played back through a computer’s sound card.

Computer Graphics

Images created using computers and stored in digital formats.

Still Images

Photos and computer graphics that are not in motion.

Motion Graphics

Digital video and animation that create the illusion of motion; opposite of still graphics.

Bitmap Graphic

An image, such as a digital photo, that is stored as a gridwork of colored dots.

Pixel

Short for picture element; the smallest unit in a graphic image. Computer display devices use a matrix of pixels to display text and graphics.

Scanner

A device that converts a printed image into a bitmap graphic.

CCD (charge-coupled device)

One of the components in a digital camera that captures light from an image and converts it into color data.

Photosites

In digital photography, a single point on an image capture chip, equivalent to one pixel.

BMP

The native bitmap graphics file format of Microsoft Windows.

RAW

In the context of digital graphics, a file that contains unprocessed image data directly from a digital camera’s sensors.

TIFF (Tagged Image File Format)

A bitmap image file format with the .tif extension that automatically compresses file data.

JPEG (Joint Photographic Experts Group)

A format that uses lossy compression to store bitmap images. JPEG (pronounced “JAY-peg”) files have a .jpg extension.

GIF (Graphics Interchange Format)

A bitmap graphics file format, popularized by CompuServe, for use on the Web.

PNG (Portable Network Graphics)

A type of graphics file format similar to but newer than GIF and JPEG.

RGB Color Model

The use of red, green, and blue light that can be combined to create the full spectrum of colors.

Color Depth

The number of bits that determines the range of possible colors that can be assigned to each pixel. For example, an 8-bit color depth can create 256 colors.

True Color

A color image with a color depth of 24 bits or 32 bits. Each pixel in a True Color image can be displayed using any of 16.7 million different colors.

Image Resolution

The number of pixels in an image, usually expressed as horizontal pixels × vertical pixels.

Resolution Dependent

Graphics, such as bitmaps, in which the quality of the image is dependent on the number of pixels constituting the image.

Pixelation

Describes the effect of increasing the size of an image until smooth edges become jagged.

Pixel Interpolation

A process that is used by graphics software to average the color of adjacent pixels in an image, usually when the image is enlarged.

Image Compression

Any technique that is used to reduce the size of a file that holds a graphic.

Run-Length Encoding (RLE)

A graphics file compression technique that looks for patterns of bytes and replaces them with messages that describe the patterns.

Image Histogram

An interactive graph that can be used to adjust the colors in a digital photo.

Cloning

In the context of digital graphics, the process of replicating a section of an image, often used to cover blemishes or fill in backgrounds.

Inpainting

The process of reconstructing missing parts of digital images, usually by means of an algorithm built into graphics software.

Digital Compositing

Assembling parts from multiple digital images into a single image.

Clipping Path

The outline of an object in a digital image that can be used to cut out the object from its background.

Alpha Blending

The process of combining a foreground color with background colors, as when an image is pasted onto a background and the edges are blended to look more natural.

Image Stitching

The process of combining two or more images together to produce a panoramic scene.

Stereoscopic Imaging

A graphical technique used to produce the sense of three dimensions from the use of one or more 2D images.

Stereo Pair

A set of two images that produce the sense of 3D when viewed one image per eye through a stereoscope.

Stereogram

Two images from a stereo pair that are combined into a single slide.

Anaglyph

A method of achieving 3D effects using two differently colored images.

Vector

Lines and curves that form simple shapes.

Vector Graphic

An image generated from descriptions that specify the position, length, and direction in which lines and shapes are drawn.

SVG (Scalable Vector Graphics)

A graphics format designed specifically for Web display that automatically resizes when displayed on different screens.

Rasterization

The process of superimposing a grid over a vector image and determining the color depth for each pixel.

3D Graphics

A digital graphics format that displays a three-dimensional image in a two-dimensional space.

Wireframe

A representation of a 3D object using vectors, which resemble wire, to create a model.

Rendering

In graphics software, the process of creating a 3D solid image by covering a wireframe drawing and applying computer-generated highlights and shadows.

Ray Tracing

A technique by which light and shadows are added to a 3D image.

Vector Animation

A series of vector images designed to be viewed sequentially to impart a vision of motion.

Frame

In the context of digital video, one of the sequential images that are combined to produce video footage.

Keyframe

In animation and video, the beginning frame of a transition or movement sequence.