1. ECE 692 – Advanced Topics in Computer Vision
Lecture 4 – Morphology
02/09/16

2. Morphology Pre- and post-processing
Morphological filter
Extract image components that are useful in the representation and description
Boundary
Skeleton

3. Morphological Operators - Dilation9 8 7 6 5 4 3 2 1 4 3 2 1 -1 -2 -3 -4 -5 9 8 7 6 5 4 3 2 1
Check to see if B needs to be reflected.
-5 -4 –3 –2 –
A = {(2,8),(3,6),(4,4),
(5,6),(6,4),(7,6),(8,8)}
A+B = {(2,8),(3,6),(4,4),
(5,6),(6,4),(7,6),(8,8),
(2,9),(3,7),(4,5),(5,7),
(6,5),(7,7),(8,9)}
B = {(0,0),(0,1)}
B: structuring element (s.e)
Always includes (0,0)

4. Morphological Operators - Erosion9 8 7 6 5 4 3 2 1 9 8 7 6 5 4 3 2 1 2 1 -1 -2
–2 – B
A-B A

5. Example Gray-level because of negative values Relief: dilate-original
Sunken: erode-original

6. Other Morphological Operators
Opening
Closing
Application???

7. Example
Opening
Closing

8. Morphological Filter (opening + closing)

9. Application – Edge Linking

10. Application

11. The Hit-or-Miss Transformation
B1 or D: shape of interest
W: window
W-D: window that surrounds D

12. Some Basic Morphological Algorithms
Boundary extraction
Hole filling
Extraction of connected components
Skeletons

13. Boundary Extraction

14. Hole Filling X0 is a point within the region with holes.
Conditional Dilation

15. Extraction of Connected Components
X0 is a point on the region.
Conditional Dilation

16. Gray-scale Morphology
Dilation
Finding max in the neighborhood
Erosion
Finding min in the neighborhood