A bitmap image uses one bit per pixel.
State the limitation this places on the number of colours in the image.
Mark scheme
Award one mark for any of the following:
- Only two different colours can be represented/stored (1)
- Each pixel can only be one of two values (1)
- The image can only be shown in black and white (1)
Allow answers that give the number of colours, e.g. two colours, 2 colours
Allow any pair of two colours, e.g. black and white, black and grey
Do not accept low resolution/poor quality/lower quality
Do not accept only one colour/can only show black
Do not accept 2 bits/2^1 without a statement about the number of colours that can be represented
Example answers and how they were marked
Only two colours can be represented, such as black and white.
Why: States that only two different colours can be represented (1)
The image will have a low resolution.
Why: Confuses colour depth with resolution; low resolution is not accepted
The image can only show black.
Why: One colour is all a single value can give; the limitation is that only two colours can be represented, so this is not accepted