Unit 1. COLOUR BY NUMBERS

HOW DO COMPUTERS STORE IMAGES?

Computer screens are divided up into a grid of small dots called pixels (picture elements). When a computer stores a picture, all that it needs to store is which dots are black and which are white.  

Let's practice with this worksheet. 

**Remember that the first number is always the number of WHITE SQUARES in the first column. If the first number is "0", then there are no white squares on the first column.

WHAT ABOUT COLOURED PIXELS?

Remember that RGB colours have 255 posibilities of colour plus white colour. If we combine the 3 colours, we will have 16,777.216 possible colours – more than the human eye can detect!

Can you remember the meaning of RGB colours?  Yes, colours that are made using Red, Green and Blue. Do you remember how computers make yellow? You can see it here: 

 https://www.csfieldguide.org.nz/en/interactives/colour-matcher/   

How bits affect the quality and colour of an image? 

You can test it here: https://www.csfieldguide.org.nz/en/interactives/image-bit-comparer/ 

What's inside each coloured pixel in a photograph? You can get an answer here: https://www.csfieldguide.org.nz/en/interactives/pixel-viewer/ 

LET’S EXPERIMENT WITH COLOURS!