A-level Physics (Advancing Physics)/Digital Processing/Worked Solutions

1. How could the above methods be applied to a digital sound sample?

By taking the median or mean of the sample and the values on either side of it. This would be unreliable, as sound is a wave, so the samples need to vary quite widely. However, something similar could be used when comparing repeating patterns in a waveform.

'''2. Which of the above methods would be suitable for smoothing sharp edges? Why?'''

Mean smoothing - median smoothing would not blur the edges.

3. Use median smoothing to remove noise from the following image of a white cat in a snowstorm (the black pixels have a value of 255):

4. Why would mean sampling not be appropriate for smoothing the image given in question 3?

It would produce a really blurred mess, instead of an image, as the noise is too dense.

5. Use mean smoothing to remove noise from the following image of a black cat in a coal cellar: