practical computer vision-- a problem-driven approach towards learning cv/ml/dl
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Practical Computer Vision A problem-driven approach towards learning CV/ML/DL
Albert Y. C. Chen, Ph.D.Vice President, R&D
Viscovery
Albert Y. C. Chen, Ph.D.
• Experience 2017-present: Vice President of R&D @ Viscovery 2016-2017: Chief Scientist @ Viscovery 2015: Principal Scientist @ Nervve Technologies 2013-2014 Computer Vision Scientist @ Tandent 2011-2012 @ GE Global Research
• Education Ph.D. in Computer Science, SUNY-Buffalo M.S. in Computer Science, NTNU B.S. in Computer Science, NTHU
1. W. Wu, A. Y. C. Chen, L. Zhao, and J. J. Corso. Brain tumor detection and segmentation in a CRF framework with pixel-wise affinity and superpixel-level features. International Journal of Computer Assisted Radiology and Surgery, 2015.
2. S. N. Lim, A. Y. C. Chen and X. Yang. Parameter Inference Engine (PIE) on the Pareto Front. In Proceedings of International Conference of Machine Learning, Auto ML Workshop, 2014.
3. A. Y. C. Chen, S. Whitt, C. Xu, and J. J. Corso. Hierarchical supervoxel fusion for robust pixel label propagation in videos. In Submission to ACM Multimedia, 2013.
4. A.Y.C. Chen and J.J. Corso. Temporally consistent multi-class video-object segmentation with the video graph-shifts algorithm. In Proceedings of IEEE Workshop on Applications of Computer Vision, 2011.
5. D.R. Schlegel, A.Y.C. Chen, C. Xiong, J.A. Delmerico, and J.J. Corso. Airtouch: Interacting with computer systems at a distance. In Proceedings of IEEE Workshop on Applications of Computer Vision, 2011.
6. A.Y.C. Chen and J.J. Corso. On the effects of normalization in adaptive MRF Hierarchies. In Proceedings of International Symposium CompIMAGE, 2010.
7. A.Y.C. Chen and J.J. Corso. Propagating multi-class pixel labels throughout video frames. In Proceedings of IEEE Western New York Image Processing Workshop, 2010.
8. A. Y. C. Chen and J. J. Corso. On the effects of normalization in adaptive MRF Hierarchies. Computational Modeling of Objects Represented in Images, pages 275–286, 2010.
9. Y. Tao, L. Lu, M. Dewan, A. Y. C. Chen, J. J. Corso, J. Xuan, M. Salganicoff, and A. Krishnan. Multi-level ground glass nodule detection and segmentation in ct lung images. Medical Image Computing and Computer-Assisted Intervention, 2009.
10. A.Y.C. Chen, J.J. Corso, and L. Wang. Hops: Efficient region labeling using higher order proxy neighborhoods. In Proceedings of IEEE International Conference on Pattern Recognition, 2008.
Some work done before I caught the startup fever
Freestyle Sketching Stage
AirTouch waits in background for the initialization signal
Initialize
Terminate
Output
imagedatabase
Start:Results
CBIRquery
Airtouch HCI interface for Content-based Image Retrieval
Interactive Segmentation & Classification• Segmentation then classification:
• computationally more efficient, • results in much higher classification accuracy.
• Pioneered the “pixel label propagation” field. • First to utilize superpixels and supervoxels for the task.
FG
Traditional Spatial Propagation
Pixel label map
Label a subset of pixels
BG
Spatio-temporal Propagation
time
Image/Video Object Recognition and Content Understanding
approaches
person carries
gives
recieves
Ontology
object
Person 1 Person 1Person 2
High-Level
Mid-Level
approachactivity
receives givescarries
activityactivity activity
Time
Reasoning
xx
x
Low-Level
x x
x
x
Learning and Adapting Optimal Classifier Parameters
subspace B
subsp
ace A
subspace C
Image-level feature space
priors
Patch-level feature space
posteriorprobability
suggest optimal parameter configuration
Graphical Models and Stochastic Optimization
A
(a) The space-time volume of a video showing the objects (A--F) and their appearing time-span.
spac
e
time
AB
C
D
E F
B E
F
C
D
(b) The temporal relationship graph. An edge between two vertices mean that the two objects overlap in time.
(c) The goal is: cover all objects with the smallest number of "ground truth key frames".
spac
e
time
AB
C
D
E F
key 1 key 2
A
B E
F
C
D
(d) This translates to: iteratively solving the max clique problem until all vertices belong to a clique.
A
B E
F
C
Dkey 2
key 1frame t-1 frame t
layer n layer n
layer n+1 layer n+1
TemporalShift
Shift
µ
Medical Imaging and Geospatial Imaging
GNN detection and segmentation
in Lung CT geospatial imaging: building detection
Brain tumor detection and segmentation in MR images.
Why are we here today?
To make a better change for our future.
Change is the only constant-Heraclitus (535 BC - 475 BC)
Change is the only constant-Heraclitus (535 BC - 475 BC)
Why Risk Innovating?
• Good business model NEVER last forever.
• Average “shelf life” on S&P 500: 20 years.
• 100-year old companies constantly reinvent themselves every 10-20 years
• Startups contribute to 20% of USA’s GDP.
The Death of a Good Business Model
• Foxconn 20 year revenue v.s. net profit (now at 5%)
What do 100 year old corporations do?
GE Schenectady, 1896
History of change at GE• 1886: one of the 12 original companies on the Dow
Jone Industrial Average (also the only one remaining). • 1889: lightbulbs • 1919: radios • 1927: TV • 1941: jet engine • 1960: nuclear power • 1971: room AC units • 1995: MRI
History of change at IBM• 1960s: mainframe computer • 1980s: personal computer • 2000s: integrated solutions • 2020s: AI, Watson
How about the leading Semiconductor companies?
NVidia reinventing itself —2 times in 20 years
“Bad money drives out good” in the desktop GPU market
The rise of mobile computing, and how NVidia missed the boat!
NVidia’s Tegra mobile processors never took off
then, the market saturated…
NVidia not just survived. NVidia is thriving!
Meet the new NVidia: Deep Learning, Deep Learning, and still, Deep Learning
The king is dead, long live the king!
Now, again, do we want to do OEM/ODM forever?
Optimizing an old business model is just delaying its eventual death.
Computer Vision, it can’t be that hard, right?
hmm… grayscale color can’t work alone… maybe color works better?
Computer Vision, it can’t be that hard, right?
White and Gold or
Blue and Black?
The Dress 2015/02/26
Computer Vision, it can’t be that hard, right?
Even if we can auto-correct all lighting and color temperature
[w w w w] [w r r w] [w r r w] [w w w w]
and force all apples to be encoded as:
we’d still have all these “affine transformation” issues:
Even if lighting, color, affine transformation are not an issue
• Our 3D world can’t simply be represented by fixed 2D encoding:
Brief History
Marvin Minsky
“In 1966, Minsky hired a first-year undergraduate student and assigned him a problem to solve over the summer: connect a television camera to a computer and get the machine to describe what it sees.”
Gerald SussmanThe student never worked on Computer Vision problems again.
Brief History• 1960’s: interpretation of synthetic worlds • 1970’s: some progress on interpreting selected images • 1980’s: ANNs come and go; shift toward geometry and increased
mathematical rigor • 1990’s: face recognition; statistical analysis in vogue • 2000’s: broader recognition; large annotated datasets available; video
processing starts
Guzman ‘68 Ohta Kanade ‘78 Turk and Pentland ‘91
What was in our arsenal?
• Image filters
• Feature descriptors
• Classifiers
Filters: blurring
Filters: sharpening
Filters: Canny Edge Detector
Filters: straight lines
Features: a compact and (hopefully) invariant representation
Features: Gabor
Features: Harris Corners
Features: Laplacian of Gaussian (LoG; scale detection)
Features: OrientationHow to compute the rotation?
Create edge orientation histogram and find peak.
Features: SIFT
Features: SIFT
Classifier Training in Machine Learning
Classification Clustering
Regression DimensionReduction
supervised unsupervised
cont
inuo
usdi
scre
te
Classifiers: SVM
Classifiers: Ensemble
Classifiers: Random Fields
Classifiers: Deformable Parts Model (DPM)
Meta-Learning• Different use
cases calls for different ML algorithms.
• Meta-Learning: learning how to learn.
• Requires plenty of domain-specific know-how.
Neural Network (NN) Why didn’t it work; why now?
• MNIST digit data 28x28 • LeCunn’s 3 layer NN:
1170 variables. • Require tens of
thousands of samples. • Only learn simple line/
curve combinations
AI Winter (1970-1980, 1990-2000) • Early NN problems:
• redundant structure, • slow learning speed • need too much data • bad learning
stability.
What’s in a NN
( )zσ+
( )zσ+
( )zσ+
( )zσ+Input
weights
bias
activation function
NN breakthroughs since 1970’s 1. Better Network Structure
• Convolutional Neural Network greatly reduces the number of variables in NN’s designed for images and videos. —> Improved convergence speed, reduced data requirements.
Upper-left corner Bird Beak Detector
Center Bird Beak Detector
Almost identical, can be shared across regions
NN breakthroughs since 1970’s 1. Network Structure
NN breakthroughs since 1970’s 2. Improved Activation Functions
Large
Small
1x
2x
……
Nx
……
……
……
……
……
……
……
y1
y2
yM
NN breakthroughs since 1970’s 3. Effective Backpropagation
w1
w2
Clipping
[Razvan Pascanu, ICML’13]
NN breakthroughs since 1970’s 4. Efficient Training Methods
• Mini-batch
• Adaptive Learning Rate
• Dropout, Batch-normalization
minibatchminibatch
1 epoch
Deep Neural Networks (DNN) way more complex and capable!
What do DNNs learn?
• Neurons act like “custom-trained filters”; react to very different visual cues, depending on data.
What do DNNs learn?
• Neurons act like “custom-trained filters”; react to very different visual cues, depending on data.
• Does not “memorize” millions of viewed images. • Extracts greatly reduced number of features that
are vital to classify different classes of data. • Classifying data becomes a simple task when
the features measured are “”good”.
What do DNNs learn?
Mature/Maturing Computer Vision Applications
• Final inspection cells • Robot guidance and
checking orientation of components
• Packaging Inspection • Medical vial inspection • Food pack checks • Verifying engineered
components[5] • Wafer Dicing • Reading of Serial
Numbers • Inspection of Saw
Blades
• Inspection of Ball Grid Arrays (BGAs)
• Surface Inspection • Measuring of Spark
Plugs • Molding Flash Detection • Inspection of Punched
Sheets • 3D Plane
Reconstruction with Stereo
• Pose Verification of Resistors
• Classification of Non-Woven Fabrics
1970s-now: Machine Vision for Industrial Inspection
• Automated Train Examiner (ATEx) Systems
• Automatic PCB inspection
• Wood quality inspection
• Final inspection of sub-assemblies
• Engine part inspection • \Label inspection on
products • Checking medical
devices for defects
Industrial Inspection: turbofan jet engine blade maintenance• Some seemingly daunting
machine vision tasks actually works with relatively simple image processing algorithms.
Industrial Inspection: Cognex Omniview
Industrial Inspection: Cognex Omniview
License Plate Recognition (1979-now)
License Plate Readers with Text Detection and Neural Networks
Biometrics
Automated Fingerprint Identification (1970s-now)
Face Recognition (1990s-now)
• Face Detection (Viola and Jones, 2001)
• Face Verification (1:1) v.s. Identification (1:N)
Face Verification and Identification, Labeled Faces in the Wild (LFW)
Recognition Accuracy: • 1 to 1: 99%+ • 1 to 100: 90% • 1 to 10,000:
50%-70%. • 1 to 1M: 30%.
LFW dataset, common FN↑, FP↓
Sports—NFL first down line (1995-now)
Sports—NFL first down line
minus
equals
3D Reconstruction(As old as CV; became practical since SIFT)
3D Reconstruction with Feature Matching, Structure from Motion
3D Reconstruction with Feature Matching, Structure from Motion
Image Panoramas (1980s - now)
Solving Panorama Problem with Markov Random Fields
Input:
Solving Panorama Problem with Markov Random Fields
Input:
Solving Panorama Problem with Markov Random Fields
Input:
Solving Panorama Problem with Markov Random Fields
Input:
Solving Panorama Problem with Markov Random Fields
Input:
Solving Panorama Problem with Markov Random Fields
Input:
Solving Panorama Problem with Markov Random Fields
Input:
Solving Panorama Problem with Markov Random Fields
Solving Panorama Problem with Markov Random Fields
ICM (Iterated Conditional Modes), 1986
Solving Panorama Problem with Markov Random Fields
Belief Propagation (1980-2000)
Solving Panorama Problem with Markov Random Fields
Graph-Cuts (alpha expansion), 2001
Photosynthesis
Solving Photosynthesis Problems with Alpha-matting (2000s-now)
Object Detection & Classification state-of-the-art
• ImageNet Large Scale Visual Recognition Challenge (ILSVRC) • 1000+ classes, 1.2M images.
0
0.125
0.25
0.375
0.5
11 12 13 14 11 12 13 14classification
errorclassification
+localization error
Image Scene Classification• MIT Places 401
dataset.
• top-5 accuracy rates >80%.
Self-driving cars (2000s-now)
DARPA Grand Challenge (2005)
2005 winner, Stanley (Stanford), 3mph through desert
DARPA Urban Challenge (2007)
2007 winner, Boss (CMU), 13mpg through the city
Self Driving Cadillac, US congressman to airport, 2013
Google Self Driving Car, 2015
Google Self-Driving Car, 2016
Google Self-Driving Car, 2016
NVidia Self Driving Car, 2016
How did we come this far? Race car drivers know the trick
Focus on Free Space / Drivable Area, not Obstacles!
Up-and-coming Computer Vision
Applications
Structure from X, Floored
Structure from X, PIX4D
Object Recognition Blue River Technology
Augmented Reality Magic Leap
IMRSV
Retail Insights
Source: Prism Skylabs
Other Applications in Business Intelligence
• Measure brand exposure. • Measure sponsorship effectiveness. • Loss prevention and retail layout optimization.
How about Smart Surveillance?
Exciting applications many of you might be
attempting to SOLVE!!!
Problem Solving WorkflowClassical Workflow: 1. Data collection 2. Feature Extraction 3. Dimension Reduction 4. Classifier (re)Design 5. Classifier Verification 6. Deploy
Modern Brute-force workflow 1. Data collection 2. Throw everything into a Deep Neural Network 3. Mommy, why doesn’t it work ???
Classical Problem #1: Curse of Dimensionality
zesit
앉다
sentarse
• Number of Variables vs Number of Samples
Q. Who would make such naive mistakes? A. Many “newbies” repeatedly do so.
Example 1-1: illegal parking detection
legal parking samples x100 illegal parking samples x100Let’s train a 150-layer Res-Net!!!What could possibly go wrong?
Example 1-1: illegal parking detection
• Data: try cleaner data
• Feature: fine-tune with pre-trained model; don’t train from scratch
• Classifier overfitting: beware of statistical coincidences,
Example 1-2: Smart Photo Album with Google Cloud Vision
Example 1-2: Smart Photo Album with Google Cloud Vision
No effective distance measure for thousands, if not millions of dimensions (tags); would be
approximately zero most of the time.
Classical Problem #2: Overfitting Data
• Make sure your deep learning algorithm is learning better features for data, not overfitting the data with complex classifiers.
Deep Learning Cookbook
GoodResultsonTestingData?
GoodResultsonTrainingData?
YES
YES
Newactivationfunction
AdaptiveLearningRate
EarlyStopping
Regularization
Dropout
(credit: Prof. H.Y. Lee, NTU)
Example: AOI breakthroughs with Deep Learning—Metal Inspection
D Weimer et al. 2017
Example: AOI breakthroughs with Deep Learning—Textile Inspection
X
Funding Li et al. / IEEE Tran Automation Science and Engineer 2017 (to appear)
Example: AOI breakthroughs with Deep Learning—Laser Welding
Johannes Günther et al. / Procedia Technology 15 (2014) 474 – 483
Example: AOI breakthroughs with Deep Learning—Laser Welding
Johannes Günther et al. / Procedia Technology 15 (2014) 474 – 483
Example: AOI breakthroughs with Deep Learning—Serial Number Processing
S. N. Lim et al. / GE Global Research
S. N. Lim et al. / GE Global Research
Example: AOI breakthroughs with Deep Learning—Serial Number Processing
Example: AOI breakthroughs with Deep Learning—Corrosion Detection
S. N. Lim et al. / GE Global Research
Example: Dermatologist-level Skin Cancer Diagnosis with DNN+Smartphones
• 5.4M cancer cases, 58M pre-cancer cases diagnosed every year in the US.
(Andre Esteva, Sebastian Thrun, 2017)
Example: Dermatologist-level Skin Cancer Diagnosis with DNN+Smartphones
Example: Dermatologist-level Skin Cancer Diagnosis with DNN+Smartphones
Example: Hippocampus Segmentation in 7T MR Images
(Dinggang Shen, 2017)
(Dinggang Shen, 2017)
Example: Hippocampus Segmentation in 7T MR Images
(Dinggang Shen, 2017)
Example: Hippocampus Segmentation in 7T MR Images
Example: Histopathological Image Classification w. DNN
Microscopic view of Breast malignant tumor
40x 100x
200x 400x(FA Spanhol, IJCNN 2016)
Example: Histopathological Image Classification w. DNN
Example: Histopathological Image Classification w. DNN
Example: DNN for Plant Disease Detection
(S Mohanty, 2016)
Example: DNN for Plant Disease Detection
Example: DNN for Plant Disease Detection
Appendix 1: Startups• A company, partnership, or temporary
organization designed to search for a new, repeatable and scalable business model.
Your Idea• Are you passionate about it? • Is it disruptive enough? • What is your business plan?
• What is it? • Can it make money? • What is the future of the idea?
• What is your competitive advantage? • How do you build up your entry barrier?
A minimal startup team
• A hacker
• A hustler
• A hipster
Startup Timeline
Prototype• Hack out a prototype
• Spend 2-10 weeks max.
• Investors are much more likely to fund you if you have a minimal initial version of your idea.
• Hackathons are a good place to start.
• Iteratively improve the prototype
Money!
Buildup your entry barrier!
• Market (users)
• Speed
• Team
• Technology
Building entry barrier with Technology!!
Angel.co
Appendix 2: My humble attempts at putting the latest Computer
Vision algorithms to work
Intrinsic Imaging at Tandent Vision Science
Computer Vision would be half-solved without shadows!
LightOriginal Image Surface
Tandent Lightbrush
Video Tutorial for Tandent Lightbrush: https://vimeo.com/47009123
Issues• Highly anticipated, highly acclaimed, but small
crowd at $500 a license.
• Adobe Photoshop monopoly and the “not invented here” syndrome.
• Adobe’s arch-rival, Corel (Corel Draw, Paint Shop Pro, Ulead PhotoImpact) was DYING and asked too much from the botched deal.
Have fun scribbling out your shadows in photoshop!
Poor Bob from Adobe wasted 9 minutes removing just 1 shadow
Intrinsic Imaging for improving the RGB signal in autonomous driving
Intrinsic Imaging’s other applications
Retrospect
• 20 researchers burned 25 million in 8 years; investors got 50 patents in return, period.
• Overestimated the total addressable market size, in a market with existing monopoly.
• Many missed opportunities. Counterexample of the lean startup model.
Some SfM, SLAM startups
Satellite/Aerial Imagery Analysis
• 40cm resolution at 30fps for 90 sec for any location on earth. • One LEO satellite revisits any place on Earth every 3 days. • Need 24 satellites to revisit any place on Earth every 3 hours.
Challenges for Single satellite depth estimation and 3D reconstruction
• At 30fps, a LEO satellite travels 250m between two consecutive frames —> theoretically sufficient for cm-level depth estimation.
• Sources of Noise: • Camera distortions • Atmospheric Disturbance • Ground vegetation • Sub-pixel sampling noise
1 2
What happened?
• B2B customers takes too long to strike deals.
• Google ate us alive in just 3 months, while we were still pitching for VC-funding with our prototype.
Visual Search at Nervve
Retrospect• Growth pains expanding from intelligence
community clients to advertisement clients. • Forming the right team of engineers and
researchers and moving at the right pace. • For any Computer Vision/Machine Learning
company: • Researchers that cannot program—> OUT • Engineers that don’t know math —> OUT
Visual Search, Simply Smarter
Once in a lifetime opportunity in China’s video streaming market
What do we need?
Face MotionImage scene Text Audio Object
Semantics
Viscovery VDS (Video Discovery Service)
Viscovery VDS (Video Discovery Service)
Viscovery VDS (Video Discovery Service)
Challenges Encountered Along the Way
• From Product Recognition in Images, to Face, Logo, Object, Scene recognition in Videos. • Number of Categories • Recognition Accuracy • Recognition Speed
• System Architecture
• Business Model
Viscovery’s Edge• Market: first mover’s advantage in China’s video
streaming market. • Speed: we built the whole VDS thing in a few months! • Team: You! Seriously! • Technology:
• Depth • Breadth • Cloud • Customizability • Self-Learning
Life is not all rosy at startups
• High Risk, High Pressure, High Uncertainty!
• Resources are scarce, but you MUST DELIVER!
• Forming your all-star team is not that easy…
• Focus, and persistence.
Appendix 3: What can Taiwan’s academia do to help bridge the gap?
HMM….
Academia
IndustryGeneral Public
reputation and policy support
improved living standards
students
opportunity
well-trained graduates
grants and collaborations
A healthy cycle
Academia
IndustryGeneral Public
unsupportive policies
stagnant wages
useless education
unemployable graduates
A vicious cycle
no grants
no students
Where should we start? Maybe with a few more stories.
Where should we start? Maybe with a few more stories.
Where should we start? Maybe with a few more stories.
The Goldilocks zone of innovation
The Goldilocks zone of innovation
Business Relevance
Academic Relevance
plentiful resources; hierarchical organization
lack of resources; responsive organization
traditional corporations talking “innovation”
corporate research
startups struggling to survive
academic spinoffs
MSR
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