Package dev.brachtendorf.jimagehash.matcher.cached

Class ConsecutiveMatcher

java.lang.Object

dev.brachtendorf.jimagehash.matcher.TypedImageMatcher

dev.brachtendorf.jimagehash.matcher.cached.ConsecutiveMatcher

Direct Known Subclasses:

CumulativeMatcher

public class ConsecutiveMatcher
extends TypedImageMatcher

Convenience class allowing to chain multiple hashing algorithms to find similar images. The ConsecutiveMatcher keeps the hashes and buffered images in cache, allowing to add and remove hashing algorithms on the fly as well as retrieving the bufferedimage object of matches. On the flip side this approach requires much more memory and is unsuited for large collection of images.

InMemoryImage matchers apply the added hashing algorithms successively, requiring all algorithms added to agree to produce a match, discarding the result fast if one of the algorithms does not consider the images similar.

This means that the order of the hashing algorithms supplied hash has an impact on the performance, the fastest algorithm should be added first.

Author:

Kilian

Nested Class Summary

Nested classes/interfaces inherited from class dev.brachtendorf.jimagehash.matcher.TypedImageMatcher

TypedImageMatcher.AlgoSettings

Field Summary

Fields

Modifier and Type	Field	Description
protected HashSet<BufferedImage>	addedImages	keep track of images already added.
protected HashMap<HashingAlgorithm,BinaryTree<BufferedImage>>	binTreeMap	Binary Tree holding results for each individual hashing algorithm

Fields inherited from class dev.brachtendorf.jimagehash.matcher.TypedImageMatcher

steps

Constructor Summary

Constructors

Constructor	Description
ConsecutiveMatcher()

Method Summary

Modifier and Type	Method	Description
void	addHashingAlgorithm(HashingAlgorithm algo, double threshold, boolean normalized)	Append a new hashing algorithm which will be executed after all hash algorithms passed the test.
void	addImage(BufferedImage image)	Add the image to the matcher allowing the image to be found in future searches.
void	addImages(BufferedImage... imagesToAdd)	Add the images to the matcher allowing the image to be found in future searches.
void	clearHashingAlgorithms()	Remove all hashing algorithms used by this image matcher instance.
Map<HashingAlgorithm,TypedImageMatcher.AlgoSettings>	getAlgorithms()	Return an immutable map copy of the algorithms currently used in the matcher.
PriorityQueue<Result<BufferedImage>>	getMatchingImages(BufferedImage image)	Search for all similar images passing the algorithm filters supplied to this matcher.
void	printAllTrees()	Print all binary trees currently in use by this image matcher.
boolean	removeHashingAlgo(HashingAlgorithm algo)	Removes the hashing algorithms from the image matcher.

Methods inherited from class dev.brachtendorf.jimagehash.matcher.TypedImageMatcher

addHashingAlgorithm, equals, hashCode

Methods inherited from class java.lang.Object

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

Field Detail

addedImages

protected HashSet<BufferedImage> addedImages

keep track of images already added. No reason to rehash

binTreeMap

protected HashMap<HashingAlgorithm,BinaryTree<BufferedImage>> binTreeMap

Binary Tree holding results for each individual hashing algorithm

Constructor Detail

ConsecutiveMatcher

public ConsecutiveMatcher()

Method Detail

addHashingAlgorithm

public void addHashingAlgorithm(HashingAlgorithm algo,
                                double threshold,
                                boolean normalized)

Append a new hashing algorithm which will be executed after all hash algorithms passed the test.

Overrides:

addHashingAlgorithm in class TypedImageMatcher

Parameters:

algo - The algorithms to be added

threshold - the threshold the hamming distance may be in order to pass as identical image.

normalized - Weather the normalized or default hamming distance shall be used. The normalized hamming distance will be in range of [0-1] while the hamming distance depends on the length of the hash

removeHashingAlgo

public boolean removeHashingAlgo(HashingAlgorithm algo)

Removes the hashing algorithms from the image matcher.

Overrides:

removeHashingAlgo in class TypedImageMatcher

Parameters:

algo - the algorithm to be removed

Returns:

true if the algorithms was removed, false otherwise

clearHashingAlgorithms

public void clearHashingAlgorithms()

Remove all hashing algorithms used by this image matcher instance. At least one algorithm has to be supplied before imaages can be checked for similarity

Overrides:

clearHashingAlgorithms in class TypedImageMatcher

getAlgorithms

public Map<HashingAlgorithm,TypedImageMatcher.AlgoSettings> getAlgorithms()

Return an immutable map copy of the algorithms currently used in the matcher. This map is a hard copy of the hashmap and does not updated if the underlying collection gets altered

Overrides:

getAlgorithms in class TypedImageMatcher

Returns:

A map containing all algorithms used in this matcher

addImage

public void addImage(BufferedImage image)

Add the image to the matcher allowing the image to be found in future searches.

Parameters:

image - The image whose hash will be added to the matcher

addImages

public void addImages(BufferedImage... imagesToAdd)

Add the images to the matcher allowing the image to be found in future searches.

Parameters:

imagesToAdd - The images whose hash will be added to the matcher

getMatchingImages

public PriorityQueue<Result<BufferedImage>> getMatchingImages(BufferedImage image)

Search for all similar images passing the algorithm filters supplied to this matcher. If the image itself was added to the tree it will be returned with a distance of 0

Parameters:

image - The image other images will be matched against

Returns:

Similar images Return all images sorted by the hamming distance of the last applied algorithms

printAllTrees

public void printAllTrees()

Print all binary trees currently in use by this image matcher. This gives an internal view of the saved images