What factors effect the file size of an image?
- Colour depth
- Image Resolution (The amount of pixels in an image)
What is the colour depth and how do you work it out?
It’s the amount of bits in a pixel that can present a colour. The more bits there are, the more colour can be displayed
- 4 bit colour depth 16 colours (2^4)
- 8 bit colour depth = 256 (2^8)
How do you work out the file size of an image?
Resolution (pixels x pixels) x colour depth = file size
Where are image data stored?
They are stored in files where binary data is placed into a bit map.
Why do some image files have more bytes than expected?
Metadata such as:
- Data when photo was taken
- Name of file
- Location of take image
- details of the image
What is the difference between analogue and digital sound waves?
Analog are continuous and are always ‘smooth’
Digital are discrete and are a measurement of analogy waves.
What are the audio converters.
ADC - Analog-to-Digital Converter
DAC- Digital-to-Analog Converter.
What factors affect the file size of an audio file?
- Sample resolution (Audio Bit depth)
- Sample rate (Amount of analogue readings taken per second- 1hz = 1 sample per second)
- Seconds of audio
How do you calculate audio file size?
Audio bit depth (bits) x Hertz (Hz) x seconds = File Size (bytes)
