Package boofcv.alg.feature.detect.edge

Class CannyEdge<T extends ImageGray<T>,D extends ImageGray<D>>

java.lang.Object

boofcv.alg.feature.detect.edge.CannyEdge<T,D>

Direct Known Subclasses:

CannyEdgeDynamic

public class CannyEdge<T extends ImageGray<T>,D extends ImageGray<D>>
extends Object

Implementation of canny edge detector. The canny edge detector detects the edges of objects using a hysteresis threshold. When scanning the image pixels with edge intensities below the high threshold are ignored. After a pixel is found that exceeds the high threshold any pixel that is connect to it directly or indirectly just needs to exceed the low threshold. The output from this class can be configured to output a binary edge image and/or a set of contours for each point in the contour image.

Field Summary

Fields

Modifier and Type	Field	Description
protected HysteresisEdgeTraceMark	hysteresisMark
protected HysteresisEdgeTracePoints	hysteresisPts
protected GrayF32	suppressed

Constructor Summary

Constructors

Constructor	Description
CannyEdge(BlurFilter<T> blur, ImageGradient<T,D> gradient, boolean saveTrace)	Specify internal algorithms and behavior.

Method Summary

Modifier and Type	Method	Description
List<EdgeContour>	getContours()
protected void	performThresholding(float threshLow, float threshHigh, @Nullable GrayU8 output)
void	process(T input, float threshLow, float threshHigh, @Nullable GrayU8 output)	Runs a canny edge detector on the input image given the provided thresholds.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

suppressed

protected GrayF32 suppressed

hysteresisPts

protected HysteresisEdgeTracePoints hysteresisPts

hysteresisMark

protected HysteresisEdgeTraceMark hysteresisMark

Constructor Details

CannyEdge

public CannyEdge(BlurFilter<T> blur,
 ImageGradient<T,D> gradient,
 boolean saveTrace)

Specify internal algorithms and behavior.

Parameters:

blur - Initial blur applied to image.

gradient - Computes the image gradient.

saveTrace - Should it save a list of points that compose the objects contour/trace?

Method Details

process

public void process(T input,
 float threshLow,
 float threshHigh,
 @Nullable
 @Nullable GrayU8 output)

Runs a canny edge detector on the input image given the provided thresholds. If configured to save a list of trace points then the output image is optional.

NOTE: Input and output can be the same instance, if the image type allows it.

Parameters:

input - Input image. Not modified.

threshLow - Lower threshold. ≥ 0.

threshHigh - Upper threshold. ≥ 0.

output - (Might be option) Output binary image. Edge pixels are marked with 1 and everything else 0.

performThresholding

protected void performThresholding(float threshLow,
 float threshHigh,
 @Nullable
 @Nullable GrayU8 output)

getContours

public List<EdgeContour> getContours()