Representing Images (AQA GCSE Computer Science): Flashcards
📚Flashcards
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Practise the cards
15 cards from this deck
What bitmap images are made of
What bitmap images are made of
Tiny squares called pixels
How image size is measured
How image size is measured
Width × height in pixels
Formula to calculate total pixels
Formula to calculate total pixels
What resolution refers to
What resolution refers to
How many pixels packed into a given physical space
What colour depth measures
What colour depth measures
How many different colours each pixel can display
Formula for number of colours from bits
Formula for number of colours from bits
Number of colours from 1 bit per pixel
Number of colours from 1 bit per pixel
2 colours
Number of colours from 8 bits per pixel
Number of colours from 8 bits per pixel
256 colours
Number of colours from 16 bits per pixel
Number of colours from 16 bits per pixel
65,536 colours
Number of colours from 2 bits per pixel
Number of colours from 2 bits per pixel
4 colours
Effect of higher resolution on images
Effect of higher resolution on images
Sharper, more detailed, larger file size
Formula for bitmap file size in bytes
Formula for bitmap file size in bytes
Why divide by 8 in file size calculation
Why divide by 8 in file size calculation
To convert bits to bytes (8 bits = 1 byte)
Effect of increasing colour depth on file size
Effect of increasing colour depth on file size
File size increases (more bits per pixel needed)
File size: 100×150 pixels, 8-bit colour depth
File size: 100×150 pixels, 8-bit colour depth
15,000 bytes (or about 15 KB)