Learning on the Fly:
Rapid Adaptation to the Image
Erik Learned-Miller
with Vidit Jain, Gary Huang,
Laura Sevilla Lara, Manju Narayana,
Ben Mears
Computer Science Department
“Traditional” machine learning
 Learning happens from large data sets
• With labels: supervised learning
• Without labels: unsupervised learning
• Mixed labels: semi-supervised learning,
transfer learning,
learning from one (labeled) example,
self-taught learning,
domain adaptation
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Learning on the Fly
 Given:
• A learning machine trained with traditional methods
• a single test image (no labels)
 Learn from the test image!
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Learning on the Fly
 Given:
• A learning machine trained with traditional methods
• a single test image (no labels)
 Learn from the test image!
• Domain adaptation where the “domain” is the new
image
• No covariate shift assumption.
• No new labels
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An Example in Computer Vision
 Parsing Images of Architectural Scenes
Berg, Grabler, and Malik ICCV 2007.
• Detect easy or “canonical” stuff.
• Use easily detected stuff to bootstrap models of harder
stuff.
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Claim
 This is so easy and routine for humans that it’s
hard to realize we’re doing it.
• Another example…
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Learning on the fly…
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Learning on the fly…
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Learning on the fly…
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What about traditional methods…
 Hidden Markov Model for text recognition:
• Appearance model for characters
• Language model for labels
• Use Viterbi to do joint inference
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What about traditional methods…
 Hidden Markov Model for text recognition:
• Appearance model for characters
• Language model for labels
• Use Viterbi to do joint inference
 DOESN’T WORK!
Prob(
|Label=A) cannot be well estimated,
fouling up the whole process.
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Lessons
 We must assess when our models are broken,
and use other methods to proceed….
• Current methods of inference assume probabilities are
correct!
• “In vision, probabilities are often junk.”
• Related to similarity becoming meaningless beyond a
certain distance.
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2 Examples
 Face detection (CVPR 2011)
 OCR (CVPR 2010)
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Preview of results: Finding false negatives
Viola-Jones
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Eliminating false positives
Viola-Jones
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Eliminating false positives
Viola-Jones
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Run a pre-existing detector...
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Run a pre-existing detector...
Key
Face
Non-face
Close to
boundary
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Gaussian Process Regression
learn smooth mapping
from appearance to score
negative
positive
apply mapping to borderline
patches
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Major Performance Gains
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Comments
 No need to retrain original detector
• It wouldn’t change anyway!
 No need to access original training data
 Still runs in real-time
 GP regression is done for every new image.
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Noisy Document
Initial Transcription
We fine herefore t
linearly rolatcd to the
when this is calculated
equilibriurn. In short,
on the null-hypothesis:
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Premise
 We would like to fine confident words
to build a document-specific model,
but it is difficult to estimate Prob(error).
 However, we can bound Prob(error).
 Now, select words with
• Prob(error)<epsilon.
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“Clean Sets”
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Document specific OCR
 Extract clean sets (error bounded sets)
 Build document-specific models from clean set
characters
 Reclassify other characters in document
• 30% error reduction on 56 documents.
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Summary
 Many applications of learning on the fly.
 Adaptation and bootstrapping new models is
more common in human learning than is
generally believed.
 Starting to answer the question: “How can we do
domain adaptation from a single image?”
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