4. Data representation: Images and Sound Flashcards
(20 cards)
Bitmap images are made up of…
pixels
A pixel is the…
smallest unit of an image
Resolution is the…
concentration of pixels within a specific area
Resolution =
Height x Width
Area is defined by…
Width x Height
Each pixel is given a…
Binary value
Each value represents a…
colour e.g. 1 = Black, 0 = White
Having more colours will…
Increase the image quality & therefore increase file size
Bits per pixel (2n)
The bit depth which represents the number of colours in an image
How much colours are in 8 bits per pixel?
This means the bit depth is 8.
2 x 2 x 2 x 2 x 2 x 2 x 2 x 2
= 256 colours
Metadata
Is data about data
Examples of metadata
- Colour depth in bits per pixel
- Resolution
- Date created
Equation for file size of an image
Image height x Image width x Colour bits
A to D
Analogue to Digital converter (Samples are stored in binary)
D to A
Digital to Analogue converter
How is sound digitized?
By repeatedly measuring and recording the sound wave
Sampling is where a sound wave is…
measured at a regular time interval
Sample rate
Number of samples taken per second
Sample resolution
Number of bits used per sample
How can sound file size be increased?
By increasing sampling rate and resolution
