1.3 File compression

Question 1

Lossless file compression

Answer 1

file compression method where the original file can be restored following decompression

Question 2

Lossy file compression

Answer 2

file compression method where parts of the original file cannot be recovered during decompression, so some of the original detail is lost

Question 3

JPEG

Answer 3

Joint Photographic Expert Group - a form of lossy file compression based on the inability of the eye to spot certain colour changes and hues

Question 4

MP3/MP4 files

Answer 4

file compression method used for music and multimedia files

Question 5

Audio compression

Answer 5

method used to reduce the size of a sound file using perceptual music shaping

Question 6

Perceptual music shaping

Answer 6

method where sounds outside the normal range of hearing of humans, for example, are eliminated from the music file during compression

Question 7

Bit rate

Answer 7

number of bits per second that can be transmitted over a network

it is a measure of the data transfer rate over a digital telecoms network

Question 8

Run-length encoding (RLE)

Answer 8

a lossless file compression technique used to reduce text and photo files in particular