Module imagingbook.common

Package imagingbook.common.edges

Class CannyEdgeDetector

java.lang.Object

imagingbook.common.edges.CannyEdgeDetector

All Implemented Interfaces:

EdgeDetector

public class CannyEdgeDetector
extends Object
implements EdgeDetector

This class implements a Canny edge detector for grayscale and RGB images. See Sec. 16.3 (Alg. 16.3) of [1] for more detail. The edge detector is "lazy" in the sense that it performs local non- maximum suppression and edge tracing only when the results are explicitly queried (by the methods getEdgeBinary() and getEdgeTraces()).

[1] W. Burger, M.J. Burge, Digital Image Processing – An Algorithmic Introduction, 3rd ed, Springer (2022).

Version:

2022/09/04 converted to implement interface, use PixelPack

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	CannyEdgeDetector.Parameters

Constructor Summary

Constructors

Constructor	Description
CannyEdgeDetector(ImageProcessor ip)	Constructor using default parameters.
CannyEdgeDetector(ImageProcessor ip, CannyEdgeDetector.Parameters params)	Constructor using specific parameters.

Method Summary

Modifier and Type	Method	Description
ByteProcessor	getEdgeBinary()	Returns a binary edge image, obtained by rendering the detected edge traces.
FloatProcessor	getEdgeMagnitude()	Returns the calculated edge magnitude for each pixel as a FloatProcessor.
FloatProcessor	getEdgeOrientation()	Returns the calculated edge orientation for each pixel as a FloatProcessor.
List<EdgeTrace>	getEdgeTraces()	Returns a list of detected EdgeTrace instances.

Methods inherited from class java.lang.Object

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

Constructor Details

CannyEdgeDetector

public CannyEdgeDetector(ImageProcessor ip)

Constructor using default parameters.

Parameters:

ip - the image to be processed

CannyEdgeDetector

public CannyEdgeDetector(ImageProcessor ip,
 CannyEdgeDetector.Parameters params)

Constructor using specific parameters.

Parameters:

ip - the image to be processed

params - a CannyEdgeDetector.Parameters object

Method Details

getEdgeMagnitude

public FloatProcessor getEdgeMagnitude()

Description copied from interface: EdgeDetector

Returns the calculated edge magnitude for each pixel as a FloatProcessor.

Specified by:

getEdgeMagnitude in interface EdgeDetector

Returns:

the edge magnitude map

getEdgeOrientation

public FloatProcessor getEdgeOrientation()

Description copied from interface: EdgeDetector

Returns the calculated edge orientation for each pixel as a FloatProcessor.

Specified by:

getEdgeOrientation in interface EdgeDetector

Returns:

the edge orientation map

getEdgeBinary

public ByteProcessor getEdgeBinary()

Returns a binary edge image, obtained by rendering the detected edge traces. See also getEdgeTraces()

Returns:

a binary image (ByteProcessor)

getEdgeTraces

public List<EdgeTrace> getEdgeTraces()

Returns a list of detected EdgeTrace instances.

Returns:

a list of EdgeTrace instances