|
Some tools use trace combs to find edges
and contours. The trace combs guarantee a very selective edge tracing. You
decide where and in what direction to search. That means you can set the
tool to search only for specific edges. The disadvantage is that you
need knowledge of orientation and image position of the measuring object.
Here
you find more information on Trace
combs.
Below
you see the general basis for the tool set-up. This is separated in the
following parts:
Parameters guiding
trace combs
|
Parameters
|
Description
|
|
Start
point/Center point
|
Either
start point or center point are given for the trace comb’s base line
|
|
Length
|
The
base line length
|
|
Angle
|
The
base line angle
|
|
Resolution
|
The
distance between the trace lines, given as a step length along the
base line.
|
Parameters guiding
trace lines and intensity profile calculation
|
Parameters
|
Description
|
|
Start
position
|
Start
of the trace lines relative to the base line
|
|
End
position
|
Stop
of the trace lines relative to the base line
|
|
Step length
|
The
distance between the measuring points along the trace lines. In each
point the image intensity is measured. The measured intensity points
makes up the intensity profile. The standard step length is one pixel.
Normally there is no purpose to have a larger step length than 1
pixel, but experience have shown that smaller step length 1/2 or 1/3
pixel will increase the accuracy.
|
|
Line
width
|
This can
be 0,1,2,…, and denotes the number of pixels looked at on each side
of the trace line. Set the line width greater than zero to average
several side-by-side values for
each point on the trace line. This is very useful when there is noise
and you want to improve the accuracy. The time of the analysis is linearly
increasing with this parameter.
|
Parameters guiding
edge detection
|
Parameters
|
Description
|
|
Threshold
|
Threshold
for the edge detection. Either used to find edges as threshold
crossings or to filter ripples when top/bottom detection is used
(extreme values).
|
|
Edge
type
|
Decides
which combinations of tops/bottoms and threshold transitions you want
to find.
|
|
