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DetectRidges_AsRegion


Header: FIL.h
Namespace: fil
Module: FoundationBasic

Extracts a pixel-precise region of bright or dark thin lines.

Applications: Consistent detection of thin structures like scratches, cracks or lines.

Syntax

C++
C#
 
void fil::DetectRidges_AsRegion
(
	const fil::Image& inImage,
	ftl::Optional<const fil::Region&> inRoi,
	float inStdDevX,
	ftl::Optional<float> inStdDevY,
	float inRidgeThreshold,
	float inRidgeHysteresis,
	fil::Polarity::Type inPolarity,
	const int inMinBlobArea,
	fil::Region& outRidgeRegion
)

Parameters

Name Type Range Default Description
Input value
 inImage const Image& Input image
Input value
 inRoi Optional<const Region&> NIL Region of interest
Input value
 inStdDevX float 0.0 - 3.0f Smoothing standard deviation (horizontal)
Input value
 inStdDevY Optional<float> 0.0 - NIL Smoothing standard deviation (vertical, or Auto = horizontal)
Input value
 inRidgeThreshold float 0.0 - 5.0f Sufficient ridge strength; ridges of that strength will always be detected
Input value
 inRidgeHysteresis float 0.0 - 4.0f Value by which the ridge threshold is decreased for ridge points neighboring with sufficiently strong edges
Input value
 inPolarity Polarity::Type
Input value
 inMinBlobArea const int 0 - 1 Minimal area of a ridge blob
Output value
 outRidgeRegion Region&

Hints

  • Connect an input image to the inImage input.
  • Set inPolarity in accordance to which type of thin lines you want to detect.
  • Start with inRidgeHysteresis = 0 and set inRidgeThreshold so that each important edge is at least partially detected. Then keep increasing inRidgeHysteresis until the edges are detected completely.
  • If the edges are rugged or there are too many false edges, then try increasing inStdDevX.

Hardware Acceleration

This operation supports automatic parallelization for multicore and multiprocessor systems.