region-based image retrieval with high level...

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www.infotech.monash.edu Region Region - - Based Image Retrieval with Based Image Retrieval with High Level Semantics High Level Semantics Ying Liu, Dengsheng Zhang and Ying Liu, Dengsheng Zhang and Guojun Guojun Lu Lu Gippsland School of Info Tech, Monash University, Gippsland School of Info Tech, Monash University, Churchill, Victoria, 3842 Churchill, Victoria, 3842 { { dengsheng.zhang dengsheng.zhang , , guojun.lu}@infotech.monash.edu.au guojun.lu}@infotech.monash.edu.au

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Page 1: Region-Based Image Retrieval with High Level …users.monash.edu.au/~dengs/resource/papers/Region-based... 2 Outline • The Problem • Content-based Image Retrieval—CBIR • Semantic

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RegionRegion--Based Image Retrieval withBased Image Retrieval withHigh Level SemanticsHigh Level Semantics

Ying Liu, Dengsheng Zhang and Ying Liu, Dengsheng Zhang and GuojunGuojun LuLuGippsland School of Info Tech, Monash University, Gippsland School of Info Tech, Monash University,

Churchill, Victoria, 3842Churchill, Victoria, 3842

{{dengsheng.zhangdengsheng.zhang, , guojun.lu}@infotech.monash.edu.auguojun.lu}@infotech.monash.edu.au

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OutlineOutline•• The ProblemThe Problem•• ContentContent--based Image Retrievalbased Image Retrieval——CBIRCBIR•• Semantic GapSemantic Gap•• Low Level Image FeaturesLow Level Image Features•• Learning Image Semantics Using Decision TreeLearning Image Semantics Using Decision Tree•• Performance TestPerformance Test•• Integrate with GoogleIntegrate with Google——SIEVESIEVE•• Experiments and ResultsExperiments and Results•• ConclusionsConclusions

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The ProblemThe Problem

•• We are in a digital world, and we are We are in a digital world, and we are inundated with digital images.inundated with digital images.

•• How to organize large image database to How to organize large image database to facility convenient search.facility convenient search.

•• How to find required images becomes a How to find required images becomes a headache for Internet users.headache for Internet users.

•• ItIt’’s a gold mining issue.s a gold mining issue.

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TheThe ProblemProblem

Find similar images from databaseFind similar images from database

Tiger

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ChallengesChallenges

•• Images are not as structured as text Images are not as structured as text documents.documents.

•• Metadata description of an image is not Metadata description of an image is not enough.enough.

•• Human description of image content is Human description of image content is subjective.subjective.

?

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ContentContent--basedbased ImageImage RetrievalRetrieval (CBIR)(CBIR)

•• Represent images with content features.Represent images with content features.

•• Color: histogram, dominant color.Color: histogram, dominant color.

•• Shape: moments, Fourier descriptors, Shape: moments, Fourier descriptors, scale space method.scale space method.

•• Texture: statistical method, fractal Texture: statistical method, fractal method, spectral method.method, spectral method.

•• Region: blob, arbitrary, block.Region: blob, arbitrary, block.

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CBIRCBIR——StateState--ofof--thethe--ArtArt

•• Limited success in a number of specific Limited success in a number of specific domain.domain.

•• Industrial object recognition.Industrial object recognition.

•• CAD and other design database CAD and other design database management.management.

•• Museum visual document managementMuseum visual document management

•• Trademark retrieval.Trademark retrieval.

•• No commercial CBIR system for WWW.No commercial CBIR system for WWW.

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ChallengesChallenges——Semantic GapSemantic Gap•• Conventional contentConventional content--based image retrieval (CBIR) systems put visual based image retrieval (CBIR) systems put visual

features ahead of textual information. features ahead of textual information.

•• However, there is a gap between visual features and semantic feaHowever, there is a gap between visual features and semantic features tures (textual information) which cannot be closed easily.(textual information) which cannot be closed easily.

Courtesy of M

d. MonirulIslam

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Cause of the Semantic GapCause of the Semantic Gap

•• Low level features are usually used Low level features are usually used individually.individually.

•• Single type of features cannot describe Single type of features cannot describe image completely.image completely.

•• Spatial information is usually ignored.Spatial information is usually ignored.

•• Images are usually treated globally while Images are usually treated globally while users are usually interested in objects users are usually interested in objects instead whole image.instead whole image.

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Narrow Down the Semantic GapNarrow Down the Semantic Gap

•• Divide an image into objects/regions.Divide an image into objects/regions.

•• Describe objects/regions using multiple Describe objects/regions using multiple type of features.type of features.

•• Learn semantic concepts from large Learn semantic concepts from large number of region samples.number of region samples.

•• Use the learned semantic concepts to Use the learned semantic concepts to describe images.describe images.

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ImageImage SegmentationSegmentation

•• Segment images into regions using JSEG technique. Segment images into regions using JSEG technique. ((Y. Deng and B. S. Y. Deng and B. S. ManjunathManjunath, IEEE PAMI, 2001, IEEE PAMI, 2001))

•• JSEG segments images using a combination of JSEG segments images using a combination of colorcolorand texture features.and texture features.

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RegionRegion RepresentationRepresentation——ColorColorFeaturesFeatures•• Represent regions using their dominant Represent regions using their dominant colorcolor

in HSV space.in HSV space.

Regions and their dominant colors

Segmentation HSV Histogram

dominant color

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GaborGabor FiltersFilters

∑∑ −−=s t

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GaborGabor FiltersFilters

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Region RepresentationRegion Representation——GaborGaborTexture FeaturesTexture Features

NnMmyxGnmEx y

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•• GaborGabor texture features are obtained by computing the mean and texture features are obtained by computing the mean and standard deviation of each filtered image.standard deviation of each filtered image.

(B. S. Manjunath and W. Y. Ma, IEEE PAMI, 1996)

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RegionRegion SimilaritySimilarity Measurement Measurement ——Earth Mover Distance (EMD)Earth Mover Distance (EMD)

•• EMD is a distance modelled with the traditional transportationEMD is a distance modelled with the traditional transportation problem which problem which is solved using the linear programming optimisation. is solved using the linear programming optimisation. ((Y. Rubner, ICCV98Y. Rubner, ICCV98))

Subject to

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TRand

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LearningLearning ImageImage SemanticsSemantics UsingUsingDecisionDecision TreeTree•• Given a set of training samples described by a Given a set of training samples described by a

set of input attributes, decision tree classifies set of input attributes, decision tree classifies the samples based on the values of the given the samples based on the values of the given attributes. attributes.

•• A decision tree (DT) is obtained by recursively A decision tree (DT) is obtained by recursively splitting the training data into different subsets splitting the training data into different subsets according to the possible values of the selected according to the possible values of the selected attribute, until data samples in each subset attribute, until data samples in each subset belong to same class. belong to same class.

•• DT is very close to human reasoning, and is the DT is very close to human reasoning, and is the only machine learning tool which can produce only machine learning tool which can produce human comprehensible rules.human comprehensible rules.

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DecisionDecision TreeTree•• A decision tree consists of leaf nodes and nonA decision tree consists of leaf nodes and non--leaf nodes. leaf nodes. •• Each leaf node of the decision tree represents a decision Each leaf node of the decision tree represents a decision

(outcome) whereas each non(outcome) whereas each non--leaf node corresponds to an leaf node corresponds to an input attribute with each branch being a possible value of input attribute with each branch being a possible value of the attribute. the attribute.

•• Given a decision tree generated from the training samples, a Given a decision tree generated from the training samples, a new data instance can be classified by starting at the root new data instance can be classified by starting at the root node of the decision tree, testing the attribute specified by node of the decision tree, testing the attribute specified by this node and moving down the tree branch corresponding this node and moving down the tree branch corresponding to the value of the attribute. to the value of the attribute.

•• This process is then repeated until a leaf node (a decision) This process is then repeated until a leaf node (a decision) is reached. is reached.

•• Once trained, a set of decision rules in Once trained, a set of decision rules in ‘‘ifif--thenthen’’ format can format can be derived for decision making. be derived for decision making.

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DecisionDecision TreeTree•• DT is an intuitive top down approach.DT is an intuitive top down approach.•• DT is used by human being for dayDT is used by human being for day--toto--day decision making.day decision making.

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LearningLearning MechanismMechanism

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Semantic TemplatesSemantic Templates•• 19 concepts are selected for training, 19 concepts are selected for training, 30 training 30 training

sample regions are collected for every concept.sample regions are collected for every concept.•• Semantic templates (ST) are generated as the Semantic templates (ST) are generated as the

centroidcentroid of the lowof the low--level features of the 30 sample level features of the 30 sample regions.regions.

•• Using the Using the STsSTs, the continuous, the continuous--valued valued colorcolor and and texture features are converted to texture features are converted to colorcolor and texture and texture labels which are discrete in value. labels which are discrete in value.

•• The labels are used as discrete attribute values for The labels are used as discrete attribute values for input to the decision tree.input to the decision tree.

•• Decision tree so derived is called DTDecision tree so derived is called DT--ST.ST.

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Decision CriteriaDecision Criteria

•• Start with 19x30=570 sample regions. Start with 19x30=570 sample regions.

•• Every region is described by a set of three Every region is described by a set of three discrete attributes: discrete attributes: colorcolor label, texture label and label, texture label and colorcolor--texture (CT) label. texture (CT) label.

•• Calculate the gain of each attribute ACalculate the gain of each attribute Aii::

Gain(AGain(Aii) = ) = HH((CC) ) –– EE(A(Aii) )

Where H(C) is the entropy of the training dataset, Where H(C) is the entropy of the training dataset, E(AE(Aii) is the ) is the expect information of Aexpect information of Aii

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Learning Image Semantics Using DTLearning Image Semantics Using DT--STST

•• Gain(ColorGain(Color) = 2.46) = 2.46•• Gain(TextureGain(Texture) = 2.01) = 2.01•• Gain(CTGain(CT) = 2.90) = 2.90

•• CT has highest information gain, it CT has highest information gain, it requires least amount of information to requires least amount of information to split the dataset for decision making.split the dataset for decision making.

•• Therefore CT is selected as the root Therefore CT is selected as the root attribute of the decision tree.attribute of the decision tree.

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Learning Image Semantics Using DTLearning Image Semantics Using DT--STST

•• The dataset is then divided into 19 The dataset is then divided into 19 subsets corresponding to each of the 19 subsets corresponding to each of the 19 possible values of CT. possible values of CT.

•• The 19 subsets so formed are then The 19 subsets so formed are then prepre--prunedpruned to remove the data samples to remove the data samples whose class probability is less than a whose class probability is less than a threshold threshold k (10%)k (10%). .

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Learning Image Semantics DTLearning Image Semantics DT--STST

•• Subsets corresponding to CT values 2, Subsets corresponding to CT values 2, 4, 5, 7, 9, 10 and 11 are homogeneous. 4, 5, 7, 9, 10 and 11 are homogeneous.

•• Therefore, branches with CT labels 2, 4, Therefore, branches with CT labels 2, 4, 5, 7, 9, 10, and 11 end up as leaf nodes 5, 7, 9, 10, and 11 end up as leaf nodes with the corresponding outcome: with the corresponding outcome: Blue Blue sky, Flower, Sunset, Firework, Ape fur, sky, Flower, Sunset, Firework, Ape fur, Eagle and Building, respectively.Eagle and Building, respectively.

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Learning Image Semantics Using DTLearning Image Semantics Using DT--STST

First half of the treeFirst half of the tree

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Learning Image Semantics Using DTLearning Image Semantics Using DT--STST

•• The subsetsThe subsets corresponding to the rest of the CT corresponding to the rest of the CT labels labels are declared as nonare declared as non--leaf nodes. leaf nodes.

•• These subsets require further splitting by using These subsets require further splitting by using other attributes. other attributes.

•• Attribute CT is removed from the attribute setAttribute CT is removed from the attribute set AAsince it has been used. since it has been used.

•• The tree induction process is recursively The tree induction process is recursively applied to each of the nonapplied to each of the non--leaf node subsets. leaf node subsets.

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PrePre--pruning pruning •• During each repeat, the tree is preDuring each repeat, the tree is pre--prunedpruned to

removeemove the data samples whose class probability the data samples whose class probability is less than a threshold is less than a threshold kk

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PostPost--pruning pruning •• The tree so formed has leaf nodes labelled with The tree so formed has leaf nodes labelled with

‘‘unknownunknown’’. .

•• However, a tree with too many However, a tree with too many ‘‘unknownunknown’’outcomes fails to classify many data instances. outcomes fails to classify many data instances.

•• It is necessary to postIt is necessary to post--prune the prune the ‘‘unknownunknown’’leaves. leaves.

•• Replacing all Replacing all ‘‘unknownunknown’’ leaf nodes with the leaf nodes with the class label having the highest probability in the class label having the highest probability in the immediate parent node.immediate parent node.

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PostPost--pruningpruning•• ColorColor=Not 8 is replaced with concept Tiger as it has highest probabil=Not 8 is replaced with concept Tiger as it has highest probabilityity•• Similarly, for Color = 8, Texture=Not 7&8, the subset compriseSimilarly, for Color = 8, Texture=Not 7&8, the subset comprises s

concepts for which the probability of Tiger is the highest. Tconcepts for which the probability of Tiger is the highest. Therefore the herefore the ‘‘unknownunknown’’ for the branch Texture = Not (7,8) is changed to for the branch Texture = Not (7,8) is changed to ‘‘TigerTiger’’..

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Final Decision TreeFinal Decision Tree

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Derived Decision RulesDerived Decision Rules

•• This set of decision rules is the actual classifierThis set of decision rules is the actual classifieror machine.or machine.

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Experiments and ResultsExperiments and Results

•• Three different datasets are selected to Three different datasets are selected to test the performance of the decision test the performance of the decision tree.tree.

•• TestSetTestSet 1: 19x20=380 regions.1: 19x20=380 regions.

•• TestSetTestSet 2: 19x25=475 regions.2: 19x25=475 regions.

•• TestSetTestSet 3: 19x40=760 regions.3: 19x40=760 regions.

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Test on PreTest on Pre--pruning Thresholdpruning Threshold•• In all the test sets, the decision tree obtained gives best In all the test sets, the decision tree obtained gives best

performance when performance when kk = 0.1 .= 0.1 .

•• PrePre--pruning effectively prevents tree from fragmentation pruning effectively prevents tree from fragmentation and noise.and noise.

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Performance Test with PostPerformance Test with Post--pruningpruning

•• The The ‘‘unknownunknown’’ outcomes are replaced with the highest outcomes are replaced with the highest probability class label.probability class label.

•• The average classification accuracy is improved by about The average classification accuracy is improved by about 24.7% by using post24.7% by using post--pruning.pruning.

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Test of False Positive ErrorTest of False Positive Error

•• 50 regions irrelevant to any of the 19 50 regions irrelevant to any of the 19 concepts are selected to test the false concepts are selected to test the false positive classification. positive classification.

•• Overall, 82% of the 50 irrelevant regions Overall, 82% of the 50 irrelevant regions are categorized as irrelevant to the are categorized as irrelevant to the training concepts. training concepts.

•• False positive error is 18%.False positive error is 18%.

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Comparison of DTComparison of DT--ST with ID3 and C4.5ST with ID3 and C4.5

•• We We compare the classification accuracy of DTcompare the classification accuracy of DT--ST with ST with ID3 and C4.5. ID3 and C4.5.

•• ID3 and C4.5 are implemented using WEKA machine ID3 and C4.5 are implemented using WEKA machine learning package. learning package. ((http://http://www.cs.waikato.ac.nzwww.cs.waikato.ac.nz/ml/weka//ml/weka/))

0.6420.6420.6230.6230.6420.642ID3(ID3(discret attribute valuediscret attribute value))0.7040.7040.7430.7430.7680.768C4.5(C4.5(discret attribute valuediscret attribute value))0.6260.6260.6670.6670.6840.684C4.5(C4.5(continue attribute valuecontinue attribute value))0.7070.7070.7580.7580.7680.768DTDT--STST

TestSet3TestSet3TestSet2TestSet2TestSet1TestSet1

Classification accuracies for the Classification accuracies for the three datasetsthree datasets

Tree induction methodTree induction method

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Retrieval Performance of DTRetrieval Performance of DT--STST

•• Commonly used Corel image database is Commonly used Corel image database is selected for the image retrieval test. selected for the image retrieval test.

•• The Corel database consists of 5,000 images of The Corel database consists of 5,000 images of 50 categories.50 categories.

•• JSEG segmentation produces 29187 regions JSEG segmentation produces 29187 regions from these images, an average of 5.84 regions from these images, an average of 5.84 regions per image. per image.

•• Average Precision (P) of 40 queries is obtained Average Precision (P) of 40 queries is obtained at each level of Recall (R=10,20,at each level of Recall (R=10,20,……100%). 100%).

•• The 40 query images are selected from the 50 The 40 query images are selected from the 50 categories excluding those with very abstract categories excluding those with very abstract category labels such as category labels such as ‘‘AustraliaAustralia’’. .

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Performance of DTPerformance of DT--ST on Image ST on Image RetrievalRetrieval•• The proposed RBIR system supports query by The proposed RBIR system supports query by

regions. regions. •• The user specify the dominant regions in the The user specify the dominant regions in the

query image. query image. •• Using DTUsing DT--ST, the system first finds a list of ST, the system first finds a list of

images that contain regions with the same images that contain regions with the same concept as that of the query. concept as that of the query.

•• Then, based on their lowThen, based on their low--level color and texture level color and texture features, these images are ranked according to features, these images are ranked according to their EMD distances to the query image. their EMD distances to the query image.

•• This is named as This is named as retrieval with conceptsretrieval with concepts. .

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Performance of DTPerformance of DT--ST on Image ST on Image RetrievalRetrieval

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Retrieval ExamplesRetrieval Examples

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Integration of DTIntegration of DT--ST with GoogleST with Google——SIEVE SIEVE

•• Currently, text based image search engines are Currently, text based image search engines are not based on CBIR. not based on CBIR.

•• The textual description in existing search engines The textual description in existing search engines may not capture image content.may not capture image content.

•• We propose to integrate the existing textWe propose to integrate the existing text--based based image search engine with visual features. image search engine with visual features.

•• A postA post--filtering algorithm is proposed, it is called filtering algorithm is proposed, it is called SIEVESIEVE——Search Images Effectively through Visual Search Images Effectively through Visual EliminationElimination. .

•• Practical fusion methods are also proposed to Practical fusion methods are also proposed to integrate SIEVE with contemporary textintegrate SIEVE with contemporary text--based based search engines. search engines.

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SIEVESIEVE——The IdeaThe Idea•• The idea of using SIEVE is very similar to The idea of using SIEVE is very similar to

object classification done by a human being. object classification done by a human being.

•• First, objects of interest are roughly First, objects of interest are roughly distinguished from other very different distinguished from other very different objects either manually or through certain objects either manually or through certain hand tools (hand tools (Google in this caseGoogle in this case). ).

•• Then, the collected objects are subject to Then, the collected objects are subject to visual inspection (visual inspection (SIEVE in this caseSIEVE in this case) to ) to confirm each object of interest from confirm each object of interest from unwanted objects.unwanted objects.

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SIEVESIEVE——The ApproachThe Approach

•• In our approach, textIn our approach, text--based image based image search results for a given query are search results for a given query are obtained at the first step. obtained at the first step.

•• SIEVE is then used to filter out those SIEVE is then used to filter out those images which are semantically irrelevant images which are semantically irrelevant to the query. to the query.

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SIEVESIEVE——The SystemThe System

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ExperimentExperiment——Image CollectionsImage Collections

•• To test the retrieval performance of SIEVE, 10 To test the retrieval performance of SIEVE, 10 queries are selected, including queries are selected, including mountain, mountain, beach, building, firework, flower, forest, snow, beach, building, firework, flower, forest, snow, sunset, tiger sunset, tiger and and seasea. .

•• Google image search can return up to Google image search can return up to thousands of images for a query, however, thousands of images for a query, however, users are usually only interested in the first few users are usually only interested in the first few pages. pages.

•• Therefore, for each query, the top 100 images Therefore, for each query, the top 100 images are downloaded from the first 5 pages.are downloaded from the first 5 pages.

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ExperimentExperiment——Measurement Measurement

•• In Web image search scenario, it is not In Web image search scenario, it is not known how many relevant images there known how many relevant images there are in the database for a given query. are in the database for a given query.

•• BullBull’’s eye measurement is used. s eye measurement is used.

•• The bullThe bull’’s eye measures the retrieval s eye measures the retrieval precision among the top precision among the top KK retrieved retrieved images.images.

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ResultsResults——Retrieval AccuracyRetrieval Accuracy

0.6

0.7

0.8

0.9

1

0 10 20 30 40 50K

Prec

isio

n

SIEVE Google

Average retrieval precision for 10 image concepts

As m

ore images are retrieved, SIEVE

shows significant gain over G

oogle.

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ResultsResults——Retrieval ExamplesRetrieval Examples

Above: Search result by Google Above: Search result by Google using query using query ‘‘TigerTiger’’

Left: Result by SIEVE using the Left: Result by SIEVE using the same query same query ‘‘TigerTiger’’

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ResultsResults——Retrieval ExamplesRetrieval Examples

Above: Search result by Google Above: Search result by Google using query using query ‘‘SnowSnow’’

Left: Result by SIEVE using the Left: Result by SIEVE using the same query same query ‘‘SnowSnow’’

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ResultsResults——Retrieval ExamplesRetrieval Examples

Above: Search result by Google Above: Search result by Google using query using query ‘‘FireworkFirework’’

Right: Result by SIEVE using the Right: Result by SIEVE using the same query same query ‘‘FireworkFirework’’

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Method of IntegrationMethod of Integration

•• Scenario 1Scenario 1—— SIEVE is installed on the server. SIEVE is installed on the server. User sends an image search query a Web User sends an image search query a Web browser. Search engine returns the SIEVED browser. Search engine returns the SIEVED images to the user.images to the user.

•• Scenario 2Scenario 2—— SIEVE is integrated with the Web SIEVE is integrated with the Web browser as a plugbrowser as a plug--in. A user query is directed in. A user query is directed by the SIEVE to search engine. The returned by the SIEVE to search engine. The returned list is subject to SIEVE. list is subject to SIEVE.

•• Scenario 3Scenario 3—— SIEVE is used as an application SIEVE is used as an application software. SIEVE directs user query to various software. SIEVE directs user query to various Web image search engines. The returned lists Web image search engines. The returned lists from search engines are further SIEVED.from search engines are further SIEVED.

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IssuesIssues•• Significant time on image segmentation and Significant time on image segmentation and

computing image semantics. This can be solved by computing image semantics. This can be solved by indexing images semantics upfront in image search indexing images semantics upfront in image search engines.engines.

•• Although a limited concept set is used to test its Although a limited concept set is used to test its performance, the decision tree can accommodate performance, the decision tree can accommodate more semantic concepts. more semantic concepts.

•• SIEVE can be applied more effectively if images in SIEVE can be applied more effectively if images in database are first classified into categories.database are first classified into categories.

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ConclusionsConclusions•• A semantic image retrieval using decision tree A semantic image retrieval using decision tree

learning has been proposed.learning has been proposed.•• The key characteristics of the DTThe key characteristics of the DT--ST are discrete ST are discrete

attribute inputs, preattribute inputs, pre--pruning and postpruning and post--pruning.pruning.•• DT produces human comprehensible rules which no DT produces human comprehensible rules which no

other machine learning tools can do.other machine learning tools can do.•• Test results on concept learning show the proposed Test results on concept learning show the proposed

DTDT--ST outperforms existing DT techniques.ST outperforms existing DT techniques.•• Experimental results on image retrieval show the Experimental results on image retrieval show the

DTDT--ST is promising and gives better result than ST is promising and gives better result than conventional CBIR technique.conventional CBIR technique.

•• Application of DTApplication of DT--ST on WWW has also been tested ST on WWW has also been tested and shown promising result.and shown promising result.

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Future WorkFuture Work

•• The system will be extended to learn a The system will be extended to learn a much larger number of concepts for much larger number of concepts for practical semantic image retrieval.practical semantic image retrieval.

•• System will be improved to accept System will be improved to accept keyword search to create a prototype keyword search to create a prototype Image Google.Image Google.

•• Various query interfaces will be Various query interfaces will be investigated including relevance investigated including relevance feedback, spatial query etc.feedback, spatial query etc.

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Publications from This ResearchPublications from This Research

1. Y. Liu, D. S. Zhang and G. Lu, "Region-Based Image Retrieval with High-Level Semantics using Decision Tree Learning", Accepted in Pattern Recognition, Dec., 2007.

2. Y. Liu, D. S. Zhang and G. Lu, "Narrowing Down The ‘Semantic Gap’ in Content-Based Image Retrieval—A Survey", Pattern Recognition, 40(1):262-282, 2007.

3. Y Liu, D. S. Zhang, G. Lu, "SIEVE—Search Images Effectively through Visual Elimination", Lecture Notes in Computer Science, Springer, ISBN 978-3-540-73416-1, Vol. 4577, pp.381-390, Intl. Workshop on Multimedia Content Analysis and Mining (MCAM07), Weihai, China, 30 June-1 July, 2007.

4. Y. Liu, D. S. Zhang, G. Lu and A. Tan, "Integrating Semantic Templates with Decision Tree for Image Semantic Learning", Lecture Notes in Computer Science, Springer Berlin/Heidelberg, ISSN: 0302-9743, (MMM07), 4352:185-195, 2007.

5. Y. Liu, D. S. Zhang, G. Lu and W-Y. Ma, "Study on Texture Feature Extraction in Region-based Image Retrieval System", In Proc. of IEEE International Conf. on Multimedia Modeling(MMM06), pp.264-271, Beijing, Jan.4-6, 2006.

6. Y. Liu, D. S. Zhang, and G. Lu, "Deriving High-Level Concepts Using Fuzzy-ID3 Decision Tree for Image Retrieval", In Proc. of IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP05), pp.501-504, Philadelphia, PA, USA, March 18-23, 2005.

7. Y. Liu, D. S. Zhang, G. Lu, and W.-Y. Ma, "Region-Based Image Retrieval with High-Level Semantic Color Names", In Proc. of IEEE 11th International Multi-Media Modelling Conference (MMM05), pp.180-187, Melbourne, Australia, January, 12-14, 2005.

8. Y. Liu, D. S. Zhang, G. Lu and W.-Y. Ma, "Region-based Image Retrieval with Perceptual Colors", In Proc. of 5th Pacific-Rim Conference on Multimedia (PCM04), Tokyo, Japan, Nov. 30-Dec.3, 2004.

9. Y. Liu, W. Ma, D. S. Zhang, and G. Lu, "An Efficient Texture Feature Extraction Algorithm for Arbitrary-Shaped Regions", In Proc. of IEEE 7th International Conference on Signal Processing (ICSP04), Beijing, China, Aug. 31– Sept. 4, Vol. 2, pp.1037-1040, 2004.

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ReferencesReferences• Y. Deng and B. S. Manjunath, “Unsupervised

Segmentation of Color-Texture Regions in Images and Video”, IEEE Trans. on Pattern Analysis and Machine Learning (PAMI), 23(8):800-810, 2001.

• B. S. Manjunath and W. Y. Ma, “Texture Features for Browsing and Retrieval of Large Image Data”, IEEE Transactions on Pattern Analysis and Machine Intelligence, 18(8):837-842, 1996.

• Y. Rubner, C. Tomasi and L. J. Guibas, "A Metric for Distributions with Applications to Image Databases“, in Proc. of IEEE Inter. Conf. on Computer Vision (ICCV'98), p. 59-67, Jan. 1998.

• http://www.cs.waikato.ac.nz/ml/weka/, accessed in Feb., 2008.