uniti adding colour the system described so far is fine for black and white imagesbut most images need to use colours as well instead of using just and using four possible numbers will allow an image to use four colours in binary this can be represented using two bits per pixel white blue green red while this is still not very large range of coloursadding another binary digit will double the number of colours that are available bit per pixel ( or )two possible colours bits per pixel ( to )four possible colours bits per pixel ( to )eight possible colours bits per pixel ( ) possible colours bits per pixel ( )over possible colours the number of bits used to store each pixel is called the colour depth images with more colours need more pixels to store each available colour this means that images that use lots of colours are stored in larger files representing sound sound needs to be converted into binary for computers to be able to process it to do thissound is captured usually by microphone and then converted into digital signal an analogue to digital converter will sample sound wave at regular time intervals for examplea sound wave like this can be sampled at each time sample point department of csevishnu institute of technology