Chapter 12:

Question 1

What is the purpose of a Hough transform?

Answer 1

Made to detect image lines.

Question 2

What is a normal parameterization of a line?

Answer 2

Instead of a line being defined by slope and interecpt, it can be defined by each point having a distance and angle from the origo:

xcos(Ø)+ysin(Ø) = rho

Rho is distance.

Question 3

What is the maximum distance from origo to pixel?

Answer 3

R = 0.5 * sqrt(W^2 + H^2)

Question 4

What is the hough space?

Answer 4

A line can be represented just by an angle and a distance. The Hough space is a two dimensional coordinate system with these two as parameters.

Question 5

What is a hough transform?

Answer 5

For every point in a picture, every line with different Ø and rho is generated. The corrseponding sinusoidial lines are genrated. Interesects are points that share a common line.

Question 6

What is Djikstras algorhytm?

Answer 6

Based on dynamic programming. An algorhytm that finds the path with the least cost in an image.