Module imagingbook.common

Package imagingbook.common.image.matching

Class DistanceTransform

java.lang.Object

imagingbook.common.image.matching.DistanceTransform

public class DistanceTransform
extends Object

Instances of this class calculate an approximate distance transform of a given image which is assumed to be binary (pixel value 0 = background, non-zero = foreground). For the L2 norm, the resulting distances are only an approximation. See Sec. 23.2.2 (Alg. 23.2) of [1] for additional details.

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

Version:

2022/09/16

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	DistanceTransform.DistanceType	Enum type for different distance norms used to calculate distance transforms.

Constructor Summary

Constructors

Constructor	Description
DistanceTransform(ImageProcessor I)	Constructor using the default distance norm (DistanceTransform.DistanceType.L2).
DistanceTransform(ImageProcessor I, DistanceTransform.DistanceType norm)	Constructor using the specified distance norm.

Method Summary

Modifier and Type	Method	Description
float[][]	getDistanceMap()	Returns the distance map as a 2D float array with the same size as the original image.

Methods inherited from class java.lang.Object

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

Constructor Details

DistanceTransform

public DistanceTransform(ImageProcessor I)

Constructor using the default distance norm (DistanceTransform.DistanceType.L2).

Parameters:

I - the input image

DistanceTransform

public DistanceTransform(ImageProcessor I,
 DistanceTransform.DistanceType norm)

Constructor using the specified distance norm.

Parameters:

I - the input image

norm - the distance norm

Method Details

getDistanceMap

public float[][] getDistanceMap()

Returns the distance map as a 2D float array with the same size as the original image.

Returns:

the 2D distance map.