1.3 data storage and compression Flashcards
1
Q
units to measure data
A
- bit
- nibble
- byte
- kibibyte (KiB)
- mebibyte (MiB)
- gibibyte (GiB)
- tebibyte (TiB)
- pebibyte (PiB)
- exbibyte (EiB)
2
Q
how to calculate sound file size
A
sample resolution (bits) * sample rate (Hz) * sample length (s)
3
Q
how to calculate image file size
A
image resolution (pixels) * colour depth (bits)
4
Q
need for data compression
A
reduce size of file
- less bandwidth required
- less storage space required
- shorter transmission time
5
Q
A
5
Q
effect of lossy compression
A
- reduce file size
- permanently remove data
- eg reduce colour depth, res, rate, res
5
Q
how does RLE work
A
- find patterns of repeating data
- replace with single instance of pattern
- and number that specifies how many times pattern repeated
