18. The detected edge points seldom form closed connected boundaries
that are required for image segmentation. Therefore edge linking and
boundary refinement are usually performed to complete the object
boundary delineation process.
19. The Hough transform can fit a parameterized boundary function to
a scattered set of edge points.
20. Active contours can be used to refine boundaries that have been found
by other methods.
21. The result of image segmentation can be encoded and stored conveni-
ently either as an object label map or as a boundary chain code.
References
1. E Davies, Machine Vision, Academic Press, 1990.
2. KR Castleman, Digital Image Processing, Prentice-Hall, 1996.
3. R Gonzales and R Woods, Digital Image Processing, Addison-Wesley, 1992.