Computer Science Illuminated Chapter 3 Vocab

Data

Basic values or facts

Information

Data that has been organized or processed in a useful manner

Data compression

Reducing the amount of space needed to store a piece of data

Bandwidth

The number of bits or bytes that can be transmitted from one place to another in a fixed amount of time

Compression ratio

The size of the compressed data divided by the size of the uncompressed data

Lossless Compression

A data compression technique in which there is no loss of information

Lossy Compression

A data compression technique in which there is loss of information

Analog Data

A continuous representation of data

Digital Data

A discrete representation of data

Digitize

The act of breaking information down into discrete pieces

Pules-code modulation

Variation in a signal that jumps sharply between two extremes

Reclock

The act of reasserting an original digital signal before too much degradation occurs

Signed-magnitude representation

Number representation in which the sign represents the ordering of the number (negative and positive) and the value represents the magnitude

Ten's complement

a representation of negative numbers such that the negative of I is 10 raised to k minus I.

Negative(I) =10^k-I. (K=number of digits)

Overflow

a situation where a calculated value cannot fit into the number of digits reserved for it

Radix point

The dot that separates the whole part from the fractional part in a real number in any base

Floating point

A representation of a real number that keeps track of the sign, mantissa, and exponent

Scientific notation

An alternative floating-point representation

Character set

A list of the characters and the codes used to represent each one

Keyword encoding

Replacing a frequently used word with a single character

Run-length encoding

Replacing a long series of a repeated character with a count of the repetition

Huffman encoding

Using a variable-length binary string to represent a character so that frequently used characters have short codes

Pixels

Individual dots used to represent a picture; stands for picture elements

Resolution

The number of pixels used to represent a picture

Raster-graphics format

Storing image information pixel by pixel

Vector graphics

Representation of an image in terms of lines and shapes

Video codec

Methods used to shrink the size of a movie

Temporal compression

Movie compression technique based on differences between consecutive frames

Spatial compression

Movie compression technique based on the same compression techniques used for still images

Multimedia

Several different media types