Computing - Images
AQA Computer Science 2022
How cameras capture images
In one sentence, how does a camera work?
Approximating a real image by cutting it up into a grid using a light sensor.
How is the grid of colour converted into binary in a camera?
Using an analogue-to-digital converter.
Bitmap graphics
Resolution and bit depth
Why doesn’t resolution affect the physical size of an image?
Because the size of each pixel in the image can grow or shrink to fit the size of the screen.
What is bit depth in image representation?
The amount of bits allocated to each pixel.
What is the formula for image file size?
Image metadata
What’s an example of image metadata?
- Creation date
- Width and height of image
- Colour/bit depth
- Geolocation
What’s a consequence of storing metadata in an image?
It makes the file bigger.
Vector graphics
How do vector graphics work?
Describing images as combinations of geometrical objects.
What is the advantage of vector graphics?
They do not lose quality when scaled.
What is the downside of vector graphics?
It’s hard to represent complex graphics, like a portrait.