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![](../../img/icon/DetectCircle.png)
DetectSingleCircle
Header: | AVL.h |
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Namespace: | avl |
Module: | FoundationBasic |
Finds the strongest circle of a given radius in the input image.
Applications: Detection of a circular or close-to-circular object like a hole, pin, pill or particle.
Syntax
C++
C#
void avl::DetectSingleCircle ( const avl::Image& inImage, atl::Optional<const avl::Region&> inRoi, float inRadius, float inMinScore, float inEdgeThreshold, atl::Conditional<avl::HoughCircle>& outCircle, avl::Image& diagGradientMagnitudeImage, avl::Image& diagScoreImage )
Parameters
Name | Type | Range | Default | Description | |
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inImage | const Image& | Input image | ||
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inRoi | Optional<const Region&> | NIL | Input region of interest | |
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inRadius | float | 0.0 - ![]() |
10.0f | Circle's radius |
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inMinScore | float | 0.0 - ![]() |
20.0f | Minimum matching score |
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inEdgeThreshold | float | 10.0f | Minimum accepted edge magnitude | |
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outCircle | Conditional<HoughCircle>& | Found circle | ||
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diagGradientMagnitudeImage | Image& | Visualized gradients magnitude of an input image | ||
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diagScoreImage | Image& | Calculated score for each pixel of an input image |
Description
The operation detects circular object of given radius (in pixels) in the inImage using the Hough Transform approach.
Hints
- Pass an input image to the inImage input.
- Define the expected circle radius on the inRadius input.
- Set inEdgeThreshold to define the minimum strength of edges that will be taken into account. Verify this value with the diagGradientMagnitudeImage output.
- Experimentally set the inMinScore value, whose meaning is more or less "the number of pixels voting for a particular object location".
Examples
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DetectSingleCircle performed on the sample image.
Hardware Acceleration
This operation supports automatic parallelization for multicore and multiprocessor systems.
See Also
- DetectMultipleCircles – Finds circles of a given radius in the input image using Hough Transform.
- DetectLines – Finds lines in an image using Hough Transform.
- DetectPaths – Finds a specified shape in an image using Hough Transform.
- DetectSegments – Finds segments in an image using Hough Transform.