The document summarizes a presentation on machine learning and multimedia information retrieval. It discusses how machine learning helps bridge the semantic gap in multimedia search by exploiting context from surrounding text, tags, and other metadata. It also describes how machine learning is used for tasks like detecting events in videos, classifying images into categories, and suggesting tags. Current applications of multimedia information retrieval discussed include biological image retrieval, fashion search engines, and visual search for suspects.

1. Machine Learning and Multimedia
Information Retrieval*
Integrated Knowledge Solutions
iksinc@yahoo.com
* Based on a talk at ICMLA Conference

2. Outline
• Introduction
• Bridging the Semantic Gap
• Events in Videos
• Use of Tagging in MIR
• Killer Apps of MIR
• Take Home Message
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3. Too Much Information
Which is more frustrating?
Being stuck in traffic on way to or from work
Not being able to find information you
urgently need
According to a survey by
Xerox
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4. Not a New Problem
Nalanda University was one of the first universities
in the world, founded in the 5th Century BC, and
reported to have been visited by the Buddha during
his lifetime. At its peak, in the 7th century AD,
Nalanda held some 10,000 students when it was
visited by the Chinese scholar Xuanzang.
The Royal Library of Alexandria, in Egypt, seems to have been
the largest and most significant great library of the ancient
world. It functioned as a major center of scholarship from its
construction in the third century B.C. until the Roman
conquest of Egypt in 48 B.C.
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5. However, Earlier
Data Producers
Data Consumers
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6. But Now a Days
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7. Some Relevant Numbers
Photobucket has 6.2 billion photos and Flickr
has over 2 billion.
Facebook has over 10 Billion photos and over
400 million active users.
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8. Phenomenon
• 24 hours of videos are
uploaded to YouTube
every one minute
• YouTube streams 2
billions of videos every
day
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9. So how do we get help in finding the desired
multimedia information?
MIR
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10. So What is MIR?
• Also known as CBIR (Content-based Image Retrieval) and
CBVIR (Content-based Visual Information Retrieval)
• Deals with systems that manage and facilitate searching
for multimedia documents such as images, videos, audio
clips and slides etc based on content
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11. History of MIR
• Conference on Database Applications of Pictorial Applications,
1979 (Florence, Italy)
• NSF Workshop on Visual Information Management Systems,
1992 (Redwood, CA)
• QBIC (Query By Image Content), 1993 (SPIE’s Conf on Storage
and Retrieval for Image and Video Databases), Also First ACM
Multimedia Conference
• Shift to semantic similarity from signal similarity, 1999
• Community tagging, photo and video sharing sites, 2002
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12. A Typical MIR System
Relevance
Feedback
Query Feature
Extraction
Indexing & Retrieved
Matching Results
Media Feature Features
Collection Extraction
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13. Semantic Gap
Early systems produced results
wherein the retrieved
documents were visually similar
(signal level similar) but not
necessarily similar in showing
the same semantic concept.
http://www.searchenginejournal.com/7-similarity-based-image-search-engines/8265/
Content-Based Image Retrieval at the End of the Early Years
Found in: IEEE Transactions on Pattern Analysis and Machine
Intelligence , Arnold Smeulders , Marcel Worring , Simone Santini ,
Amarnath Gupta , Ramesh Jain , December 2000
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14. Semantic Gap
Users also like to query using descriptive
words rather than query images or other
multimedia objects. This requires MIR
systems to correlate low-level features
with high level concepts.
Visually dissimilar
images representing
the same concept.
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15. How to Bridge the Semantic Gap?
Exploit context
• Text surrounding images
• Associated sound track and
closed captions in videos
• Query history
Use machine learning to:
• Build image category classifiers to
perform semantic filtering of the
results
• Build specific detectors for objects
to associate concepts with images
•Build object models using low level
features
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16. Exploiting Context: An Example
Kulesh, Petrushin and Sethi, “The PERSEUS Project: Creating Personalized Multimedia News Portal,”
Proceedings Second Int’l Workshop on Multimedia Data Mining, 2001
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17. Example of Using Surrounding Text
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18. Context via Surrounding Text
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19. Context Via Surrounding Text: One
More Example
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20. Better Context with More Text
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21. Improving Context via More Words per
Query
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22. Issues Unique to ML for MIR
• Simultaneous presence of
multiple concepts
• How to extract/isolate
concept-specific features?
Segment or do not
segment?
• Imbalance between Romance, couple, beach, sundown
From: s163.photobucket.com
positive and negative
examples
• Extremely large number
of concepts for a general
purpose MIR
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23. A Template Relating Concepts with Pictures
Concepts Image Tokens Images
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24. Feature Extraction Issues
Whole image based features.
Easy to use but not very
effective
Region based features. Both
regular region structure and
segmented regions are popular
Salient objects based features.
Connected regions
corresponding to dominant
visual properties of objects in an
image
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25. Scale Invariant Feature Transform
(SIFT) Descriptors
SIFT descriptors or its variants are
currently the most popular features
in use. Each image generates
thousands of features (key point
descriptors) with each feature
typically consisting of 128 values
http://www.vlfeat.org/
D. G. Lowe, “Distinctive image
features from scale-invariant
keypoints,” IJCV, 2004.
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26. Feature Discovery
Basic idea is to discover
features that are best
suitable for a given
collection
Mukhopadhyay, Ma, and Sethi, “Pathfinder Networks for Content Based Image Retrieval Based on
Automated Shape Feature Discovery,” ISMSE 2004
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27. Image Category Classifiers (ICC)
• Trained using both supervised and
unsupervised learning methods (SVM,
DT, AdaBoost, VQ etc)
• Early work limited to few tens of
categories; however some of the current
systems can work with thousands of
categories/concepts
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28. VQ Based Image Category Classifier
Fire Codebook
Test Best
Image Codebook
Sky Codebook Label
Mustafa & Sethi (2004)
Water Codebook
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29. Object Detectors
PASCAL Visual Object Classes Challenge
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30. Project
Web-based annotation tool to segment and label image
regions. Labeled objects in images are used as training images
to build object detectors.
12/12/2010 http://labelme.csail.mit.edu/
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31. Image Category Classifiers Examples
IMARS provides a large number of built-in classifiers for visual categories that cover places, people, objects, settings,
activities and events. It is easy to add new ones. IMARS can work on PC or laptop (trial version is available at IBM
alphaWorks). IMARS can also work at large-scale for high-volume batch processing of millions and images and videos
per day. Several demos of IMARS are available (see IMARS demos)
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32. Image Classification via Probabilistic
Modeling
Semantic labeling. (a) An MPE semantic retrieval system groups images by semantic
concept and learns a probabilistic model for each concept. (b) The system represents
each image by a vector of posterior concept probabilities.
From Pixels to Semantic Spaces: Advances in Content-Based Image
Retrieval (Nuno Vasconcelos, IEEE Computer, July 2007)
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33. Retrieving Events in Videos
• An event in MIR implies an interesting
spatiotemporal instance
• Considerable work in MIR community on
events because of popularity of sports videos
• Also tremendous interest in detecting and
recognizing events with potential homeland
security applications
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34. Event Retrieval Examples: Supervised
Approach
Mustafa & Sethi AVSS Conference 2005
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35. Unsupervised Learning for Event Retrieval
Mustafa & Sethi, ICTAI 2007
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36. Unsupervised Learning Based Event
Retrieval
Mustafa & Sethi, ICTAI 2007
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37. Retrieval By Cross-Modal Associations
- Using query from one modality (e.g. audio) to
retrieve content on a different modality (e.g. video)
- Directly on low-level features
Approaches:
Latent semantic indexing (LSI)
Li, Dimitrova, Li and Sethi (ACM Cross-modal factor analysis (CFA)
MM 03) Canonical correlation analysis (CCA)
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38. Talking Face Example
Feature
Extraction
Query
Retrieval Results
Collection
Cross-Modal
of Image
Sequences Association
.
. Feature
. Extraction
M. Li, D. Li, Dimitrova and Sethi, “Audio-Visual Talking Face Detection,” Proceedings, ICME,
2003
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39. Tagging in MIR
All time most popular tags at Flickr
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40. About Tags
• User centered
• Imprecise and often overly personalized
• Tag distribution follows power law
• Most users use very few distinct tags while a small group of users works
with extremely large set of tags
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41. How are Tags Being Used in MIR?
Relating tags in different languages through visual features
Aurnhammer, Hanappe and Steels Proc. WWW2006
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42. Tag Suggester
Kucuktunc, Sevil, Tosun, Zitouni, Duygulu, and Can (SAMT 08)
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43. Collaborative Tags
• Also known as Folksonomy, social tagging, and social
classification
• Great for content characterization
• The tag size represents the number of times the tag has
been applied to the same item by different users. It kind of
represents the level of agreement /confidence in a tag.
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44. Decision Tree Based Tagger
• Uses social tags in binary/weighted mode
• Generates/suggests multiple tags through a single decision
tree classifier
First, the label vectors associated
with training vectors are
clustered into two initial groups
Next, the SVM is used on training
vectors to yield the split that best
matches the clustering result
An impurity based measure is
used to iteratively adjust the split,
if needed
Ma, Sethi, and Patel. “Multilabel Classification Method for Multimedia Tagging”. (IJMDEM, 2010)
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47. Current Status of MIR
• Extensive interest as evident from conferences,
journals, and special issues
• Most in the MM community happy with the progress
• Gap between published results and results from
publicly available systems on web.
(http://www.theopavlidis.com/technology/CBIR/PaperB/icpr08.htm)
• Lack of application focus
• Plenty of scope for machine learning to help
improve MIR systems performance
• Killer applications are beginning to emerge
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48. MIR Application Examples
Tattoo-ID: Automatic Tattoo Image Retrieval for Suspect & Victim Identification (Anil K. Jain,
Jung-Eun Lee, and Rong Jin)
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49. Biological and Medical Data Retrieval
http://www.cs.washington.edu/research/VACE/Multimedia/
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50. Killer Apps?
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51. http://www.iqengines.com/applications.php
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52. http://www.iqengines.com/applications.php
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53. http://www.thingd.com
Bloomberg Businessweek, Nov29, 2010
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54. 12/12/2010 ICMLA Talk 54

55. Take Home Message
• MIR is emerging in the commercial domain.
Lot more activity is expected in near future
• MIR community is obsessed with general
purpose retrieval engine; a folly pursued by
computer vision community for a long time
• ML is playing a vital role in MIR
• Approaches combining social search and
visual search techniques are expected to gain
prominence
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56. Acknowledgement
• This presentation is based on the work of
numerous researchers from the MIR/ML/CVPR
community. I have tried to give
credit/references wherever possible. Any
omission is unintentional and I apologize for
that.
• Also want to thank my present and past
students and collaborators.
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57. Questions?
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