The resolution of a bitmap image can be measured.
Describe what is meant by the resolution of a bitmap image.
Mark scheme
Award up to two marks for a linked description such as:
- The number of pixels in a given area/inch (1) so a higher resolution has more pixels in the same area (1)
- The width and height of the image in pixels (1) which gives the total number of pixels (1)
- The concentration/density of pixels (1) which determines the detail/sharpness of the image (1)
- A larger number of pixels across the width and height (1) so more detail can be shown (1)
Do not accept 'how clear the image is' alone.
Do not accept the number of colours.
Do not award responses about file size.
Example answers and how they were marked
The number of pixels per inch. A higher resolution means more pixels in the same area.
Why: Point (1) that resolution is the number of pixels in a given area and development (1) that a higher resolution has more pixels in the same area.
The number of pixels across the width and height of the image.
Why: Point (1) that resolution is the width and height in pixels, but no linked development about the total number of pixels or detail.
How many colours the image can show.
Why: No credit: the number of colours is not accepted as the meaning of resolution.