CS 659 Image Processing

Exam Two

Name: Student ID #:

Covering Lectures 7~13. There are 4 questions. Each is 25 points.

1. (a) Suppose that A is an image of 6×13 and B is the structure element (note: the origin is located at the center) shown below. A: B: 0000000000000 0 1 0 0111110001110 1 1 1 0111110001110 0 1 0 0111110001110 0111111111110 0000000000000 What is the result Of A radius B? What is the result of A B? (b) Draw the quadtree representation for the following image. What is the size of a block represented by a node at level 2? Assuming the root is labeled as level 0, the next downwards are level 1, level 2, and so on.
2. (a) Apply a two-step distance algorithm to obtain the chessboard distance transform on the

following image.

(b) What is the skeleton from the above distance transformation?

(c) What is the disadvantage of the skeleton obtained by this method?
3. Apply the thinning algorithm to the following binary image. (Use 8-neighbor) Note that the deletion of non-simple pixels starts from North, and then South, West, East, and repeat the deletion until no changes.
4. How can we obtain the chain codes and crack codes by using the border following

algorithm considering 8-connectedness?

0000010

0111110

0111000

0000111

0000010

WX: codehelp