IPToolEdgeCircle
Description
determining the largest and smallest radius and edge points. The edge circle finding
tool locates edge pixels and does a best fit
circle to them. The method employed is directional and sub pixel edges
are found. The number of points found depends on the parameters
settings.

The tool employs a donut ROI ROI
Parameters
WhichEdge
The Edge of interest. By default the brightest edge is found.
Alternatly, the 1st through nth edge can be selected
EdgePolarity
The polarity of the edge
being sort, either
dark to light (1)
light to dark(-1)
don't care (0)
Smoothing
The amount of averaging
in determining the edge. Units are pixels.
Leniency
This is a measure of edge
steepness. The bigger the number the more likely the edge finder will
detect more gradual edges. Units are pixels.
MinContrast
The minimum difference in intensity
for an edge to be regarded as an edge. This is a measure of greylevel
differences. Note that typically for a greylevel image 0 is black and
255 is white. The 255 is the the maximum contrast.
ROIWidth
The number of pixels / size of the internal sub ROI used to determine
an edge. The larger the number the less sensitive the edge points are
to small edge changes. Units are pixels.
ROIStep
The number of pixels between consecutive edge points. Together with the
ROI Width this determines the number of edge points found. Units are
pixels.
FitMethod
Best Fit: determine strongest (best fit) circle
PointsDiameter:
The points calculated represent points on opposite sides of the circle.
The is a two pass approach with the first pass re-centering the ROI.
The points in alternately 180 degrees apart.
Max Inscribed Circle: Bubble use a bible technique the smallest circle
Max Inscribed Circle: Concave the smallest circle
more accurate than the bubble technique but susceptible to noise
Min Circumscribed Circle: the largest circle
HoughHough transform to fit circle
MaxNumberIterations
MaxError
this is a filter that once a circle has been fitted
points exceeding the max error are removed. This is repeated
until either the Max Error is not exceeded or we have exceeded
the max number iterations
Only applies when set to best fit fitting
PointCount
Output: The number of points found