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Computing revision mind map - Coggle Diagram
Computing revision mind map
Images
Each image is made of lots of tiny squares - or pixels. Each pixel is a single colour.
Resolution is the concentration of pixels
A higher resolution means more pixels which means better image quality but it also means a larger file size
The colour of a pixel is stored as a binary number.
size in bits = width x height x colour depth divide by 8 to get size in bytes.
metadata = data about data for example: image width,
image height, resolution, colour depth
How image is stored
Each image is a grid of pixels. Each pixel represents one single colour. Each colour has a specific binary number
How is sound stored
Sound is sampled at regular intervals. The amplitude of the wave is measured. The sample is stored as a binary number.
File size = sample rate x duration x bit depth
Binary and hex
Binary= 2 digits(1 and 0) base 2 system
Hex=16 digits(0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f) base 16
The column headers multiply by 2 each time you go to the left
The column headers multiply by 16 each time you go to the left
Binary file sizes
1)bit( 1 or 0) 2) nibble(4 bits) 3) byte(2 nibbles or 8 bits) 4) kilobyte (1000 bytes) 5) megabyte (1000 kilobytes) 6)gigabyte(1000 megabytes) 7)terabyte(1000 gigabyte) 8)petabyte(1000 terabytes) 9)yotabytes(1000 petabytes)
The bit depth indicates the range of sounds that can be captured. The more bits stored the more it will sound like the original.
Character sets
A numerical mapping of the characters available to a computer system. Each character is stored as a binary number.
Common character sets = ascii and unicode