Thresholding - Lecture 4 - Week 1

Question 1

What is segmentation?

Answer 1

Label each pixel as either object or background

Question 2

What is thresholding?

Answer 2

Selecting numbers that are above or below a given threshold value

Question 3

What can help choose threshold values?

Answer 3

An image histogram

Bi-model (two-peak) can see object pixels and background pixels

In a histogram breadth of a peak means variability, amplitude means more pixels of that type

Derivative of the area as a function of threshold

Threshold placed where rate of change of segmented area is smallest