To ensure that the result images, such as Figure 7 and 16, are comparable, I process identical image volumes for all computations. All results are represented by the same image sections of the image volume.

Usually,
each processing step offers its user a set of configurable parameters.
In the case of the gradient magnitude operator,
users can set
individual weights for each partial derivative term
or
choose among
competing finite-difference approximations of the partial derivatives.
In general,
I experiment with such processing parameters.
Because of the shear amount of possible combinations,
such experiments are usually not exhaustive.
The result images that I include in this report
are the *best* results that I found.
Similarly,
I choose individual display parameters, such as polarity and clip,
for each image.

3/8/1999