ASCII Character Set.
- 7 bits per character
- 128 max characters
- represents English
Advantage of ASCII.
- takes up less space as it only has 128 characters
Disadvantage of ASCII.
- limited amount of characters can be held
Extended ASCII Character Set.
- 8 bits per character
- 256 max characters
- represents English
What is included with Metadata?
Location
Date
Width
Height
Colour Depth
How do you calculate file size of an image?
Height x Width x Colour Depth
What is Sample Rate?
How many samples are recorded per second.
What is Bit Depth?
Amount of information stored with each sample.
How do you calculate Bit Rate?
Sample rate x Bit Depth x No. of Channels (1/2/3 bit etc.)
How do you calculate file size of a sample?
Bit Depth x Duration
Lossy Compression.
Original data can be disregarded (permanently), so less data needs to be stored.
File size decreases massively.
Doesn’t work on written documents.
Works on music, images, videos.
Lossless Compression.
Reduces file sizes by using patterns.
No loss of quality.
Less effective at reducing file sizes.
Reversible.
Works on audio, images, text documents.
