CircleHoughTool¶
The CircleHoughTool searches for a circle in the set region that best matches the given parameters, within a given search interval.
![../../../_images/CircleHoughTool.png](../../../_images/CircleHoughTool.png)
The following parameters are available for configuration:
![../../../_images/CircleHoughTool-HoughSettings.png](../../../_images/CircleHoughTool-HoughSettings.png)
Magnitude Scale: For this purpose, edge information is derived from the input image using a “Sobel filter”. The Magnitude Scale parameter is used for edge enhancement.
Smoothness: The transformation result of the edge information into Hough space is smoothed using Gaussian filter. The smoothness parameter describes the strength of the smoothing.
Radius Start: Default value of the radius start value in pixels
Radius Step: Step size by which the radius is increased in pixels.
Radius Count: Number of steps by which the start value of the radius is incremented by the step size.
Minimum Houghmax: The accumulator value in Hough space must exceed a minimum value for each radius traversed. The Minimum Houghmax parameter is specified here as a percentage of the circumference of the associated circle.
Blobthreshold (Stretch Gauss): The position (center) of the circle is obtained by a blob evaluation, where the Blob Threshold parameter is to be specified as a percentage of the Hough maximum.
Maximum Hougharea: In order to really detect a clear, as pointed as possible expression of the “Hough response”, the parameter Maximum HoughArea is used to check that the associated blob area does not exceed the specified limit.
EmbeddingEnabled: With this checkbox an “averaging” (Average over all Houghaccu) over all Hough accumulators (for all passed radii) is additionally selectable.
Determine best blob by:
DistHoughMaxToBlobBoundary
DistHoughMaxToBlobCenterOfMass
DistHoughMaxToWeightedMidpoint
MaxBlobArea
Get best circle of best blob by:
HoughMax
CenterOfMass
WeightedMidpoint
![../../../_images/CircleHoughTool-Settings2.png](../../../_images/CircleHoughTool-Settings2.png)
Enabled: Checkbox enables averaging over all Hough results for all radii traversed.
Blob Threshold: Percentage gray value specification related to the maximum smoothing.
Min Blobarea: Default minimum blob area in pixels
Intermediary images: Checkbox activates the saving of recordings under the specified path.
InputImage is edge image: By activating the checkbox, an edge image can already be provided as InputImage for evaluation.
Mutlithreading: Checkbox parallelizes processes within the CircleHoughTool for runtime optimization.
Results
The following result values are available:
ID
Radius in pixel
Radius
CenterMassX
CenterMassY
WeightedMidpointX
WeightedMidpointY
Area
ConnectivityLabel
Acircularity
DistToBoundary
DistToCenterOfMass
DistToWeightedMidpoint