CE WATER - Contrast Enhancement - Watershed Segmentation

(01/03/05)

PURPOSE

Creates watershed image. Useful for segmentation.   Example.

SEE ALSO

CE RIDGE [Contrast Enhancement - Ridge Following]
ER WA [Erode image to a "watershed"]
EC FILTER [Extract Connected Clusters - Filter]

USAGE

.OPERATION: CE WATER

.INPUT FILE: IMG001
[Enter the name of the input image file.]

.OUTPUT FILE: IMG002
[Enter name for output file.]

NOTES

  1. Does not work for volumes.

  2. First all pixels are sorted. Wartershed formation starts with the least intense pixel. This pixel is recursively connected to all adjacent pixels with equal or greater intensity to form a watershed. This process is continued with the next lowest intensity pixel which is not yet in any watershed until all pixels have been assigned to a watershed. Watersheds are numbered: 1,2.....

  3. Watershed segmentation is implementation dependent and a 'watershed' is not well defined for some topographies. E.g. what should the watershed be if you take a flat plate and put some dimples in it?

  4. You may want to 'low pass filter' your image before using this operation?

  5. You may want to use EC CL or EC FILTER in conjunction with this operation.

SUBROUTINES

WATERSHED

CALLER

UTIL2