Storing sound and images Flashcards
What is sampling?
Recording a signal (especially sound) at regular intervals
What is sampling frequency / sampling rate?
The number of samples obtained per second. Measured in Hz.
What is sample size?
The number of bits available for each sample. This is also known as ‘bit depth’ and ‘sampling resolution’.
What is a common sampling frequency?
44.1 kHz
What is bit rate?
The number of bits used per second
Bit rate = ?
Bit rate = Sampling frequency × Sample size
(bps) (Hz) (b)
What is a bitmap?
An image stored as an array of individual pixels
What is a pixel?
An individual picture element / a small dot that makes up a bitmap image
What is resolution?
The detail that an image holds. Measured either in width × height, or as ppi/dpi (pixels per inch / dots per inch)
What is colour depth / bit depth?
The number of bits allocated to represent each pixel’s colour.
What is metadata?
Extra data stored in a file which gives information about the file’s properties. Can include resolution, file format and colour depth
