Setup

Reference - Reference system selection

Circle -

• Center-X
• Center-Y
• Radius - nominell radius

Point & Click Clipboard Support

The ROI can be managed by the buttons

• Paste - paste the ROI from the image to the scorpion clipboard
• Copy - copy the ROI to the image from the scorpion clipboard

Note: Copy does not do anything when a result reference is used for circle description

Point & Click Clipboard Support

The first point of the line defines the origo of the radial tracecomb. The second point defines the tracecomb. To edit length and width of tracecomb used the tool's fields.

One point will change origo of the radial tracecomb.

Trace lines - describing the edge search area 

• Number of trace lines - Number of trace lines in search comb
• Trace start - start point relative to radius
• Trace stop -  stop point relative to radius
  • -0.5 and 0.5 gives a traceline with length 1 starting at 0.8 ending at 1.8 when radius is 1.3
• Trace step - sample step along each traceline
• Trace line width - number of pixel in each trace line

Note: A trace line width equal 3 means that each point of the trace line is calculated using the pixel value. It is recommended to increase the trace line width to improve edge detection in low contrast conditions

Edge Detection

• Smooth base - 3 is normally a good value
• Smooth counter - 1 default - given i pixels
  • The smoothing increasing with higher values
• Differentiation
  • 0 - give threshold
  • 1 - 1. order differentiation - the derivative - default normally used
  • 2 - 2. order differentiation
• Mode - Peaks are default. Threshold is only used when Differentiation is set to 0.

More information - see Normalisation

Note : Combining 2. order differentiation and polarity are used to find the center position of light or dark stripes

• Polarity - Dark to light | Light to dark | All transitions
• Threshold - value lower values means more sensitivity
• Edge choice - Largest | First | Last

Advanced

Search for optimal circle center - activate circle fitting before gauging

• Only if more edgepoints than - search is found edgepoints greater than N
  • Use center of gravity - sets center to center of gravity of edgepoints
  • Use circle fit
    • Good points - number of points required to accept circle fit
    • Max tries - number of iterations to find accepted fit
    • Fit tolerance ( pixels ) - fitted points must be inside N pixels to count as Good Points

Trace line samples dialog - a helper window to set trace line filter parameters and thresholds

• Middle - show the middle traceline
• Middle+edges - shows the first, middle and last traceline
• Selection - show the selected tracelines
• Line indices - traceline selection
  • example: 2,3,12-15
  • example: 1 3 5 7
• Show trace line popup - activates a modeless traceline window

Example tracelines - Middle+edges is selected

Constraints

Results

OK	1 or True while Constraints met
Best center	Point - (x,y) - of circle center
BestRadius	The radius of the fitted radius - only available while circle is fitted
CircleFitted	1 or True if circle fitted
Fit RMS	RMS value of Circle Fit
Radius min	Minimum radius
Radius max	Maximum radius
Radius Std	Standard deviation of radius measurements
Number of radius points
RadiusMinLine	Minimum Radius Line
RadiusMaxLine	Maximum Radius Line
Diameter min	Minimum diameter
Diameter max	Maximum diameter
Diameter Std	Standard deviation of diameter measurements
Number of diameter points
DiameterMinLine	Minimum Diameter Line
DiameterMaxLine	Maximum Diameter Line
Ovality	MaxDiameter / MinDiameter - calculated by using diameter-measurements

Visualisation

BestCenter
Center
EdgePoints
MinRadius	Minimum radius line
MaxRadius	Maximum radius line
MeanCircle
MinDiameter	Minimum diameter line
MaxDiameter	Maximum diameter line
TraceLines	Traceline used to find edgepoints
FitEdgePoints	Fitted edgepoints when fitting circle
FitTraceLines	Traceline used to fit circle

 

ExecuteCmd support (see also executeCmd)

Command	Parameters	Return values	Comments
Set	Object=ROI;Value=<point/line>	ok,res	Sets the tool's ROI. See Copy/paste ROIs for details.
Get	Object=ROI	ok,<line>	Current ROI as line from center to circumference at angle 0.