Microscope Image Processing

in real images. On the sides of the objects, the contour lines are closed and

generally convex curves, but they may have local concavities. We can assume

that each threshold gray level defines a single closed contour for each object.

Under these conditions we need to consider only the range of gray levels

corresponding to the sloping sides of the object, and the ways to establish

the maximum slope threshold can be summarized as follows:

1. Select T at a local minimum in the histogram. This is the easiest tech-

nique, and it minimizes the sensitivity of the area measurement to small

variations in T.

2. Select T corresponding to the inflection point in the h-equivalent CCS

profile function. This is a simple computation, and it involves considerable

averagi ...