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FitArcToStripe
Performs a series of 1D stripe detections and finds an arc that best matches the detected points.
Header: | AVL.h |
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Syntax
void avl::FitArcToStripe ( const avl::Image& inImage, const avl::ArcFittingMap& inFittingMap, const StripeScanParams& inStripeScanParams, avl::Selection::Type inStripeSelection, atl::Optional<const avl::LocalBlindness&> inLocalBlindness, float inMaxIncompleteness, avl::CircleFittingMethod::Type inFittingMethod, atl::Optional<avl::MEstimator::Type> inOutlierSuppression, atl::Conditional<avl::Arc2D>& outArc, atl::Conditional<avl::Arc2D>& outInnerArc, atl::Conditional<avl::Arc2D>& outOuterArc, atl::Optional<atl::Array<atl::Conditional<avl::Stripe1D> >&> outStripes = atl::NIL, atl::Optional<atl::Array<avl::Point2D>&> outStripePoints = atl::NIL, atl::Optional<atl::Conditional<avl::Profile>&> outDeviationProfile = atl::NIL, atl::Array<avl::Profile>& diagBrightnessProfiles, atl::Array<avl::Profile>& diagResponseProfiles )
Parameters
Name | Type | Range | Default | Description | |
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inImage | const Image& | Input image to fit arc to | |||
inFittingMap | const ArcFittingMap& | Input fitting map | |||
inStripeScanParams | const StripeScanParams& | Parameters controlling the stripe extraction process | |||
inStripeSelection | Selection::Type | Selection::Best | Selection mode of stripe | ||
inLocalBlindness | Optional<const LocalBlindness&> | NIL | Defines conditions in which weaker edges can be detected in the vicinity of stronger edges | ||
inMaxIncompleteness | float | 0.0 - 0.999 | 0.1f | Maximal fraction of stripe points not found | |
inFittingMethod | CircleFittingMethod::Type | AlgebraicTaubin | Method used to fit an arc | ||
inOutlierSuppression | Optional<MEstimator::Type> | NIL | Selects a method for ignoring incorrectly detected points | ||
outArc | Conditional<Arc2D>& | Fitted arc in the middle of found stripe | |||
outInnerArc | Conditional<Arc2D>& | Fitted inner arc | |||
outOuterArc | Conditional<Arc2D>& | Fitted outer arc | |||
outStripes | Optional<Array<Conditional<Stripe1D> >&> | NIL | Found stripes | ||
outStripePoints | Optional<Array<Point2D>&> | NIL | Extracted points of middle arc of an image stripe | ||
outDeviationProfile | Optional<Conditional<Profile>&> | NIL | Profile of distances between the actual arc points and the corresponding reference arc points | ||
diagBrightnessProfiles | Array<Profile>& | Extracted image profiles | |||
diagResponseProfiles | Array<Profile>& | Profiles of the edge (derivative) operator response |
Description
The operation tries to fit a given arc to stripe present in the inImage image. Internally, it performs a series of scans with the ScanSingleStripe filter using inFittingMap previously generated from the object being fitted. The found points are then used to determine the actual position of the arc in the image. Only inMaxIncompleteness fraction of these scans may fail. If the fitting according to the given parameters is not possible, outArc is set to Nil.
Hints
- Connect an input image to the inImage input.
- Define inStripeScanParams.StripePolarity to detect a particular stripe type, and only that type.
- Adjust inStripeScanParams.MinStripeWidth and inStripeScanParams.MaxStripeWidth to the expected thickness of the stripe (in pixels).
- If no or too few stripe points are found, try decreasing inStripeScanParams.MinMagnitude.
- If some of the scans may fail, set the inMaxIncompleteness input accordingly.
- If some of the scans may produce false results, try different values of the inOutlierSuppression input.
- Use the outStripePoints outputs to visualize the scanning results.
Examples
Remarks
For more information about local coordinate systems please refer to the following article.
This filter is a part of the Shape Fitting toolset. To read more about this technique, one can refer to the Shape Fitting chapter of our Machine Vision Guide
Hardware Acceleration
This operation supports automatic parallelization for multicore and multiprocessor systems.
See Also
- CreateArcFittingMap – Precomputes a data object that is required for fast arc fitting on images.
- FitArcToEdges – Performs a series of 1D edge detections and finds an arc that best matches the detected points.
- FitArcToRidges – Performs a series of 1D ridge detections and finds an arc that best matches the detected points.