CS Chap #1(Sub-topic 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 Experts Group — a form of lossy file compression based on the inability of the eye to spot certain color 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

a 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. (Instance with loud and soft sound, loud sound kept soft deleted because soft can’t be heard)

Question 7

Bit Rate

Answer 7

the number of bits transferred or received per unit of time

Question 8

Run Length Encoding (RLE)

Answer 8

a lossless file compression technique used to reduce text and photo files in particular. (Checks repetition, assigns one value to how many times it is being repeated and another value to define what is being repeated; compression data stored in File Header)

Question 9

Methods of reducing Movie Files and Image Files

Answer 9

Movie Files:
1. Reduce sampling rate
2. Reduce sampling resolution
3. Reduce frame rate

Image Files:
1. Crop image
2. Decrease color depth
3. Reduce image resolution