Collections for Automatic Image Annotation and Photo Tag Recommendation Philip McParlane, Yashar Moshfeghi and Joemon M. Jose University of Glasgow, UK

Collections for Automatic Image Annotation and Photo Tag

Recommendation

Philip McParlane, Yashar Moshfeghi and Joemon M. Jose

University of Glasgow, UK

http://www.dcs.gla.ac.uk/~philip/[email protected]

Motivation for annotating images

Problems with existing automatic image annotation collections

Problems with existing photo tag recommendation collections

Flickr-AIA

Flickr-PTR Conclusions

We introduce

We introduce




Flickr-AIA


We introduce

We introduce

With the amount of multimedia data rapidly increasing, it becomes important to organize this content effectively

Social image sharing websites depend on manual annotation of their images.

This has a large human cost however.Plus, humans often tag with irrelevant tags (e.g. girl) or tags which are opinionated (e.g. cool) etc.







Therefore,research has focussed

on the automatic annotation of images

Automatic image annotation (AIA)

Photo TagRecommendation (PTR)

AIA CollectionsMany public collections used

PTR CollectionsMostly non-public collections used

Evaluated on

Corel5k, Corel30k, ESP Game, IAPR, Google Images, LabelMe, Washington Collection, Caltech, TrecVid 2007, Pascal 2007, MiAlbum & 4 other small collections.

The 20 most cited AIA papers on CiteSeerX revealed that at least 15 collections had been used…

For photo tag recommendation, the most popular works use their own collections.

“considers the pixels” “considers those tags already added”

Evaluated on







Evaluated on





Evaluated on







Evaluated on





Evaluated on




Flickr-AIA


We introduce

We introduce

In this work we consider 3 popular AIA evaluation collections used by recent work [4]

Corel5k [1] IAPR TC-12 [2] ESP Game [3]

[1] Object Recognition as Machine Translation: Learning a Lexicon for a Fixed Image Vocabulary. P. Duygulu et al. ECCV 02.[2] Labeling images with a computer game. L. von Ahn and L. Dabbish. CHI '04.[3] The IAPR TC-12 Benchmark- A New Evaluation Resource. M. Grubinger, et al. Visual Information Systems, 2006.[4] Baselines for Image Annotation. A. Makadia, V. Pavlovic and S. Kumar. IJCV 2010

Automatic Image Annotation

What are the problems with previous automatic image annotation collections?


Too many collectionsThere needs to a be a single, openly available collection to reproduce experiments.



Annotation AmbiguityCollections use many synonyms in the annotation of images. e.g. usa/america etc.




UnnormalizedModels are able to “exploit” popular tags by promoting them, increasing performance measures.





Low Image QualityModels are often tested on small, low quality image collections.






Lack of Meta-dataDespite the increase in research considering time/location etc, these collections don’t include these.







Lack of diversityCollections often contain images taken on the same camera, at the same place by the same user.








Location TagsLocations, such as “usa”, are impossible to identify, however, these tags are often included in ground truths.








Location TagsLocations, such as “usa”, are impossible to identify, however, these tags are often included in ground truths.

CopyrightCorel is bound by copyright making distribution difficult.

1. ProblemsAnnotation Ambiguity

All three collection ground truths contain:• Synonyms

(e.g. america/usa)• Visually identical classes

(e.g. sea/ocean)

Corel5k IAPR TC-12 ESP Game

1. ProblemsAnnotation Ambiguity

All three collection ground truths contain:• Synonyms

(e.g. america/usa)• Visually identical classes

(e.g. sea/ocean)To demonstrate this, we cluster tags which share a common WordNet “synonym set” (removing irrelevant matches manually).


Corelpolar/arctic

ocean/sea36 of 374 tags

ice/frost

Corelpolar/arctic

ocean/sea

ESPbaby/child

child/kidhome/house

37 of 291 tags

36 of 374 tags

ice/frost

Corelpolar/arctic

ocean/sea

ESPbaby/child

child/kidhome/house

IAPRwoman/adult

bush/shrubrock/stone

37 of 291 tags

26 of 269 tags

36 of 374 tags

ice/frost

31%of photos in the Corel collection contain at least 1 ambiguous tag.


25%of photos in the ESP collection contain at least 1 ambiguous tag.


25%of photos in the ESP collection contain at least 1 ambiguous tag.

sixty three%of photos in the IAPR collection contain at least 1 ambiguous tag.

Annotations: sea, usa, sky, chair

Test image #1


Annotation Model #1 sea, usa, blue, water, red

Test image #1

Precision

0.4

Suggestions


Annotation Model #1

Annotation Model #2

sea, usa, blue, water, red

Test image #1

ocean, america, blue, water, red

Precision

0.4

0

Suggestions


Annotation Model #1

Annotation Model #2

sea, usa, blue, water, red

Test image #1

ocean, america, blue, water, red

Precision

0.4

0

Suggestions

So why do we penalize a

system which treats these

concepts differently?

It is impossible to tell from an image’s pixels, whether it is of the sea or of the ocean.

2. ProblemsUnnormalised Collections

By nature, the classes used in image collections follow a long tail distribution i.e. there exist a few popular tags and many unpopular tags

This causes problems:1. Selection Bias: Popular tags exist in more training and test images.

Therefore, annotation models are more likely to test on popular classes.2. Prediction Bias: Popular tags occur in more test images. Therefore,

annotation models can potentially “cheat” by promoting only popular tags, instead of making predictions based purely on the pixels.














Tags

# Im

ages

To demonstrate this “prediction bias”(i.e. where annotation models can “cheat” by promoting popular tags)

We annotate each collection using the annotation model described in [6].

We split the vocabulary into 3 subsets of popular, medium frequency and unpopular tags.

For each, we suggest only the tags in each subset.

[6] Baselines for Image Annotation. A. Makadia, V. Pavlovic and S. Kumar. IJCV 2010


Popular tags

Tags

# Im

ages







Popular tagsMedium Frequency

Tags

# Im

ages







Popular tagsMedium FrequencyUnpopular Tags

Tags

# Im

ages







Ultimately, higher annotation accuracy can be achieved by suggesting only popular tags.

3. ProblemsImage quality/size

Despite the increase in Hadoop clusters & computational power,

many works still test on small collections of low quality images.

Collection Size (avg dimension) # Images

Corel 160px 5,000

ESP 156px 22,000

IAPR 417px 20,000


4. ProblemsLack of meta-data

Many recent works have focussed on the exploitation of various meta-data [7,8]

e.g. Time, Location, Camera, User

Collection Time Location

Corel X X

ESP X X

IAPR ✓ ✓

[7] On contextual photo tag recommendation. P McParlane, Y Moshfeghi, J Jose SIGIR 2013[8] Beyond co-occurrence: discovering and visualizing tag relationships from geo-spatial. H Zhang et al. WSDM 2012


5. ProblemsLack of diversity

Images in each collection are often taken bythe same user, in the same place, of the same scene/object, using the same camera.

This leads to natural clustering in image collections, making annotation easier due to high inter-cluster visual similarity.

Further there are duplicate images in the test and train sets, also making annotation easier.


6. ProblemsIdentifying Location

Identifying location (even high level) within an image is often difficult or sometimes impossible. Despite this, two of the three collections contain images annotated with locations (e.g. usa).

Given this image, would you know where it was taken?


6. ProblemsIdentifying Location

Identifying location (even high level) within an image is often difficult or sometimes impossible. Despite this, two of the three collections contain images annotated with locations (e.g. usa).

Given this image, would you know where it was taken?


If not, how can we expect an annotation model to predict the annotation “usa”?


7. ProblemsCopyright

An evaluation collection should at least be free and distributable.

Unfortunately, the Corel collection is commercial and bound by copyright.





Flickr-AIA


We introduce

We introduce

Flickr-AIA contains 312,000 images from Flickr built with AIA evaluation in mind.


Openly availableUsing Flickr images under the creative commons license



Meta-dataIncludes extensive location, user and time meta-data.




Diverse image setWe search images for 2,000 WordNet categories & limit the number of images for each user.





High qualityThe dimension of each image is 719px on average.






No Location tagsWe use WordNet to remove “location” tags from image ground truths (e.g. scotland).







Resolved AmbiguityTags which are synonyms (e.g. usa/america) are “merged” based on WordNet synonym sets.







Resolved AmbiguityTags which are synonyms (e.g. usa/america) are “merged” based on WordNet synonym sets.

NormalizedAside from the normal ground truth, we include a “normalised” ground truth containing only medium frequency tags.




Flickr-AIA


We introduce

We introduce

In this work we consider collection used in 2 popular photo tag recommendation works.

Photo Tag Recommendation

[5] Flickr Tag Recommendation based on Collective Knowledge. B. Sigurbjornsson and R. van Zwol. WWW '08.[6] Personalized, Interactive Tag Recommendation for Flickr. N. Garg and I. Weber. ACM RecSys '08.

Sigurbjornsson [5] Garg [6]

1. ProblemsGround Truth

Sigurbjornsson use a small collection of images which have their ground truth’s crowdsourced.

For photo tag recommendation, however, many aspects that users would tag are often not explicit (e.g. locations, dates etc). Therefore, these annotations are missed using crowdsourcing.

Sigurbjornsson Garg

Crowdsourced Workerfootball redteam blueenglandgrasssaturday

Comparing AnnotationsCrowdsourced vs tags added by the user.

Crowdsourcedfootball redteam blueenglandgrasssaturday


User Tagsfootball redteam bluescotland hamilton acciesartificial grass dunfermlinesunday new douglas park

Crowdsourcedfootball redteam blueenglandgrasssaturday


User Tagsfootball redteam bluescotland hamilton acciesartificial grass dunfermlinesunday new douglas park

2. ProblemsSynonymous Tags

One of the problems with using user tags, however, is that users often use many synonyms to annotate images.

Sigurbjornsson Garg

Annotations: newyork, ny, nyc, newyorkcity, york, timessquare

Test image #1


Annotation Model #1 ny, nyc, newyork, york, city

Test image #1

Precision

0.8

Suggestions


Annotation Model #1

Annotation Model #2

ny, nyc, newyork, york, city

Test image #1

ny, timessquare, people, cab, empire

Precision

0.8

0.4

Suggestions


Annotation Model #1

Annotation Model #2

ny, nyc, newyork, york, city

Test image #1

ny, timessquare, people, cab, empire

Precision

0.8

0.4

Suggestions

3. ProblemsFree distribution

Existing collections [6,7] for photo tag recommendation were never released making comparable experiments difficult.

[6] Personalized, Interactive Tag Recommendation for Flickr. N. Garg and I. Weber. ACM RecSys '08. [7] Flickr Tag Recommendation based on Collective Knowledge. B. Sigurbjornsson and R. van Zwol. WWW '08.

Sigurbjornsson Garg




Flickr-AIA


We introduce

We introduce

Flickr-PTR contains details of 2,000,000 images from Flickr built with PTR evaluation in mind.





Clustered User TagsUsing a crowdsourced experiment which asked user to group related tags to overcome the problem of synonyms.

To overcome synonyms in image annotations we took out an crowdsourced experiment which “grouped” the synonyms or the tags which refer to the same aspect.

ConclusionsThis work highlighted: 7 problems with existing AIA collections (Corel, ESP, IAPR) 3 problems with existing PTR collections (Sigur, Garg)

With this in mind, we introduce two new, freely available image collections:

Flickr-AIA312,000 Flickr images

Flickr-PTR2,000,000 Flickr images

Automatic image annotation evaluation Photo tag recommendation evaluation

These collections are available at:

http://dcs.gla.ac.uk/~philip/

Thanks for listening!

[1] Object Recognition as Machine Translation: Learning a Lexicon for a Fixed Image Vocabulary. P. Duygulu et al. ECCV 02.[2] Labeling images with a computer game. L. von Ahn and L. Dabbish. CHI '04.[3] The IAPR TC-12 Benchmark- A New Evaluation Resource. M. Grubinger, et al. Visual Information Systems, 2006.[4] Flickr Tag Recommendation based on Collective Knowledge. B. Sigurbjornsson and R. van Zwol. WWW '08.[5] Personalized, Interactive Tag Recommendation for Flickr. N. Garg and I. Weber. ACM RecSys '08. [6] Baselines for Image Annotation. A. Makadia, V. Pavlovic and S. Kumar. IJCV 2010[7] On contextual photo tag recommendation. P McParlane, Y Moshfeghi, J Jose SIGIR 2013[8] Beyond co-occurrence: discovering and visualizing tag relationships from geo-spatial. H Zhang et al. WSDM 2012

Documents

Collections for Automatic Image Annotation and Photo Tag Recommendation Philip McParlane, Yashar Moshfeghi and Joemon M. Jose University of Glasgow, UK