Package dev.brachtendorf.jimagehash.matcher.categorize

Class KMeansClassifier

java.lang.Object

dev.brachtendorf.jimagehash.matcher.categorize.KMeansClassifier

All Implemented Interfaces:

CategoricalImageMatcher

public class KMeansClassifier
extends Object
implements CategoricalImageMatcher

The kMeans approach requires to know the number of clusters beforehand.

Since:

3.0.0

Author:

Kilian

Constructor Summary

Constructors

Constructor	Description
KMeansClassifier(int k, HashingAlgorithm hasher)

Method Summary

Modifier and Type	Method	Description
void	addImage(BufferedImage bi, String uniqueId)
CategorizationResult	categorizeImage(BufferedImage bi)	Compute the category of the supplied image.
CategorizationResult	categorizeImageAndAdd(BufferedImage bi, String uniqueId)	Compute the closest category of an image and afterwards add it to the internal categorization queue.
List<Integer>	getCategories()	Get a list of available categories this matcher matched images to.
int	getCategory(String uniqueId)	Get the current category of the image described by this unique id.
List<String>	getImagesInCategory(int category)	Get the unique id's of all images mapped to this category
void	recomputeCategories()	Recompute the category definition of this clustering matcher and it's nested matchers.

Methods inherited from class java.lang.Object

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

Methods inherited from interface dev.brachtendorf.jimagehash.matcher.categorize.CategoricalImageMatcher

categorizeImage, categorizeImageAndAdd

Constructor Detail

KMeansClassifier

public KMeansClassifier(int k,
                        HashingAlgorithm hasher)

Parameters:

k - The number of clusters to

hasher - The hashing algorithm used to create hashes

Method Detail

recomputeCategories

public void recomputeCategories()

Description copied from interface: CategoricalImageMatcher

Recompute the category definition of this clustering matcher and it's nested matchers.

Recomputing categories will take recently added images into account and update image/category affiliation if necessary. This operation needs to be called manually due to the potential high cost of this method call.

Unless otherwise noted the matcher makes no guarantee that the image category does not change with this method execution.

Specified by:

recomputeCategories in interface CategoricalImageMatcher

categorizeImage

public CategorizationResult categorizeImage(BufferedImage bi)

Description copied from interface: CategoricalImageMatcher

Compute the category of the supplied image. A category is a collection of similar images mapped to a common hash which minimizes the distance of all hashes mapped to this category.

Specified by:

categorizeImage in interface CategoricalImageMatcher

Parameters:

bi - The buffered image to categorize

Returns:

a pair whose first value returns the category and second value returns a distance measure between the category and the supplied image. Smaller distances meaning a closer match

addImage

public void addImage(BufferedImage bi,
                     String uniqueId)

categorizeImageAndAdd

public CategorizationResult categorizeImageAndAdd(BufferedImage bi,
                                                  String uniqueId)

Description copied from interface: CategoricalImageMatcher

Compute the closest category of an image and afterwards add it to the internal categorization queue. Some matchers may choose to immediately update the current category to reflect the changes.

The add action is implementation depended. Some categorizers may choose to directly incorporate the image and update it's category representation other algorithms may require a call to CategoricalImageMatcher.recomputeCategories() before the addition takes effect.

Specified by:

categorizeImageAndAdd in interface CategoricalImageMatcher

Parameters:

bi - the image to categorize

uniqueId - the unique id to reference the image by.

Returns:

the currently closest cluster for this image.

getCategories

public List<Integer> getCategories()

Description copied from interface: CategoricalImageMatcher

Get a list of available categories this matcher matched images to. Each category represents a set of images with high similarity.

Specified by:

getCategories in interface CategoricalImageMatcher

Returns:

A list of id's

getImagesInCategory

public List<String> getImagesInCategory(int category)

Description copied from interface: CategoricalImageMatcher

Get the unique id's of all images mapped to this category

Specified by:

getImagesInCategory in interface CategoricalImageMatcher

Parameters:

category - to check for

Returns:

a list of all unique id's mapped to this category

getCategory

public int getCategory(String uniqueId)

Description copied from interface: CategoricalImageMatcher

Get the current category of the image described by this unique id. A category usually maps an image to a cluster.

Specified by:

getCategory in interface CategoricalImageMatcher

Parameters:

uniqueId - the id of a previously added image

Returns:

the category