Week 8: Post Processing and Informatics

Question 1

Low-pass Filtering (Smoothing)

Answer 1

Low frequencies are amplified and the high frequencies may have been deleted or averaged into nearby pixel values. Smoothing reduces image noise and contrast which makes the image appear smoother but some detail is lost.

Question 2

High-pass Filtering (Edge Enhancement)

Answer 2

Amplifies the high frequencies or deters the low frequencies. It will make the edges or sharp boundaries appear more crips and it will increase image contrast and detail, but also increase image noise. Small structures might be buried in an enhanced edge.

Question 3

WW

Answer 3

How many greys will be displayed.

Question 4

WL

Answer 4

The centre of the range of greys. WL combined with WW creates an inverse relationship because WL is the centre of the window. WL set high creates a dark image, set low (in the negatives) creates a light image.

Question 5

Wide WW

Answer 5

Lots of different shades of grey, low contrast.

Question 6

Narrow WW

Answer 6

Fewer shades of grey, higher contrast.