AC52021: Vision and Perception
PEOPLE:
- Dr.Jesse Hoey, Module Coordinator (jessehoey@computing.dundee.ac.uk)
- Prof. Stephen McKenna, (stephen@computing.dundee.ac.uk)
- Prof. Manuel Trucco, (manueltrucco@computing.dundee.ac.uk)
- Wei (Jerry) Jia, Lab Tutor (weijia@computing.dundee.ac.uk)
TIMETABLE:
Lectures will take place in two time slots every week as follows
Monday 11:00-13:00 in Dalhousie 2S11(B) and
Friday 10:00-12:00 in Dalhousie 2F10(B)
Lab sessions will be held in QM Lab 2 on
Wednesday 9:00-11:00
full MSC-ICS timetable is here
Detailed Schedule (locations as above unless otherwise noted):
STRUCTURE
The course will consist of 7 topics (see below). For each topic, there will be an in-class lecture (usually 1.5 hours),
followed by a discussion of a research paper (also in class, usually 2 hours).
The discussions will be structured as follows.
One person will be chosen each week to present the paper, by giving a short (10-15 min) overview. The other participants are required to bring one or more exam-style discussion points/questions, or arguments against the paper. These arguments should be written down before the discussion, and the students should be prepared to discuss their arguments with the group. The written argument should be at least two sentences, preferably a short paragraph. Participation marks will be awarded for a written argument, followed by a comprehensible discussion of the argument. Examples of arguments may be
- "Why didn't they compare their method against method X. Method X is shown to perform well in paper Z, with much the same type of data. "
- "Equation N has the following error in it. It should be more like this ..., but this could be an approximation they are using as follows."
- "The data set used is too small: only showing one example is not enough to back up their claims. At least 10 examples would be necessary."
- "Why is the approximation in section Y necessary? It could be either that the computation would be too difficult, or that somehow the approximation makes things better."
Each of these examples should be followed by a brief explanation or a few discussion points. See more discussion points on the SIFT paper.
You don't have to actually know for certain that your argument is correct or what the answer is, just be prepared to discuss it. Handed-in arguments will also form the basis for exam questions.
The course content will be delivered partially as lectures, and partially as group discussion of computer vision papers.
Each week, students are expected to read the discussion paper, prepare one or more arguments, and participate in the discussion.
Further their will be two short projects to be completed and write-ups to be handed in.
Assessment
- Examination: 80% Examination with both essay-style and problem-solving questions covering all material in the course.
- Short Projects: 15% for 2 short assigned projects. Marks will be assigned based on a written report to be handed in on specified deadlines.
- Discussion Participation: 5% for participation in the discussion groups. Each week, each student will get assigned a mark if they present the paper, or if they submit a written argument and discuss their argument coherently with the group.
READINGS:
Primary Texts:
RESOURCES:
COURSE OUTLINE
Topic 1: Features (Hoey)
- gaussian filters, image scaling review
- scale space
- gradients and edges review
- corners,
- features
- invariance: scale, rotation, affine transformation
- SIFT
Lecture Material:
Discussion Reading:
David G. Lowe, Object recognition from local scale-invariant features,
International Conference on Computer Vision, Corfu, Greece (September 1999), pp. 1150-1157.
Related Readings:
- David Lowe papers and software
- Other material on Corners and Features
- K. Mikolajczyk and C. Schmid, Scale and Affine invariant interest point detectors. In IJCV 60(1):63-86, 2004. A quite general paper on the best preforming and most robust features.
- Harris' corner detection paper
- David G. Lowe, Distinctive image features from scale-invariant keypoints" International Journal of Computer Vision, 60, 2 (2004), pp. 91-110. Gives more background and updated methods for matching.
- Tony Lindeberg: Scale-space theory: A basic tool for analysing structures at different scales, J. of Applied Statistics, 21(2), pp. 224--270, 1994.
Available at Tony Lindeberg's Page
Click here for the paper
Project #1:
Scale Invariant Feature Transform. See project description page.
Due Date: Februrary 23rd (in class)
Topic 2: Optical Flow (Trucco)
- Optic flow: problems, definition, importance in machine vision
- Optic flow and motion fields
- Estimating the 3-D motion field from the optic flow; the aperture problem
- Computing the OF: Lucas-Kanande
- Computing the OF: Horn-Schunck (global regularisation)
Lecture Material:
Discussion Reading (Fri Feb 6th, 2009):
B K P Horn and B G Schunk:
Determining optic flow. Artificial Intelligence Journal, 1981.
(take a look at Ballard and Brown's overview first; see link in "Lecture Material")
Related Material:
optical flow test sequences
John Barron and Steven Beauchemin, Performance of Optical Flow Techniques. IJCV 12(1):43-77, 1994.
get the pdf here
Topic 3: Segmentation (Trucco)
- Pixel-based segmentation
- Background Subtraction (adaptive and non-adaptive)
- Model-based segmentation (templates)
- Graph Cuts
- Mean shift (intro)
- Multi-scale segmentation
- Semi-Automatic Segmentation (LiveWire)
Lecture Material:
Discussion Reading (Fri Feb 13th, 2009):
D. Comaniciu, P. Meer: Mean Shift Analysis and Applications, IEEE Int. Conf. Computer Vision (ICCV'99), Kerkyra, Greece, 1197-1203, 1999
Related Material:
A review and comparison of various segmentation techniques (ECCV 2002) by Freixenet et al.
Dorin Comaniciu and Peter Meer: Mean Shift: A Robust Approach toward Feature Space Analysis IEEE PAMI vol 24, No 5, May 2002. A longer version of the discussion reading.
Dorin Comaniciu home page
C/matlab code for doing normalized cuts, and a fancier version
Topic 4: Contours and Shape (McKenna)
- Contour representation
- Active contours
- 2D shape
- Statistical shape models using PCA
- Active shape models
Lecture Material:
See the share.
Discussion Reading:
Cootes T F, Taylor C J, Cooper D H, Graham J, Active shape models - their training and application, Computer Vision and Image Understanding 61(1), 38-59, 1995
Related Readings:
Kass M, Witkin A, Terzopoulos D, Snakes: active contour models, International Journal of Computer Vision 1(4), 321-331, 1988
CVonline: Snakes, Active Contours
Topic 5: Object Recognition (Hoey)
- Feature patterns
- Template matching
- Eigenfaces
- adaBoost for face recognition
Lecture Material:
Discussion Reading:
Viola, Paul, and Jones, M. Rapid object detection using a boosted cascade of simple features. In IEEE Computer Society Conference on Computer Vision and Pattern Recognition (Dec. 2001).
Project #2:
Face Detection with a Boosted Feature Detector. See project description page.
Due Date: March 30th (in class)
Topic 6: Tracking (McKenna)
- Revision of HMMs
- Linear-Gaussian HMMs: Kalman filter tracking
- Sequential Monte-Carlo: Particle filter tracking
- Tracking examples using visual contours, colour and sound
Lecture Material:
Discussion Reading:
Isard M and Blake A, Contour tracking by stochastic propagation of conditional density, European Conference on Computer Vision, Cambridge, 343-356, 1996
Related Readings:
Vermaak J, Gangnet M, Blake A, Perez P, Sequential Monte Carlo Fusion of Sound and Vision for Speaker Tracking, International Conference on Computer Vision 2001
Nait Charif H and McKenna S J, Tracking the Activity of Participants in a Meeting, Machine Vision and Applications 17(2):83-93, May 2006
Topic 7: Action/Event Recognition (Hoey)
- Introduction to Video
- Actions in Video: Facial Expressions, Gestures, Human Gait, Human Actions
- HMMs and Action Recognition
- Dynamic Bayesian Networks: their use for classification and recognition
Lecture Material:
Discussion Reading 1:
Alexei A. Efros, Alexander Berg, Greg Mori, Jitendra Malik.
Recognizing Action at a Distance. In Proceedings of International Conference on Computer Vision, 2003
ICCV talk
Related Readings:
Sourabh A. Niyogi, Edward H. Adelson. Analyzing and Recognizing Walking Figures in XYT Proc. IEEE Conf. Computer Vision and Pattern Recognition, pp.469-474, 1994
James J. Little and Jeffrey E. Boyd Recognising People by their Gait: The Shape of Motion, Videre, Volume 1, Number 2, Winter 1988
Thad E. Starner and Alex P. Pentland Visual Recognition of American Sign Language using Hidden Markov Models Proc. IEEE Conf on Automatic Face and Gesture Recognition, Zurich, 1995
Kevin P. Murphy and Mark A. Paskin Linear Time Inference in Hierarchical Hidden Markov Models, Proceedings of Neural Information Processing Systems (NIPS), Vancouver, BC, 2001
Nuria Oliver and Eric Horvitz
A Comparison of HMMs and Dynamic Bayesian Networks for Recognizing Office Activities
Proceedings of Int. Conf. on User Modeling (UM'05). Edinburgh, UK. Jul 2005.
Eric Horvitz, Jack Breese, David Heckerman, David Hovel, Koos Rommelse The Lumiere Project: Bayesian User Modeling for Inferring the Goals and Needs of Software Users. In Procedings of International Conference on Uncertainty in Artificial Intelligence, Madison, WI, 1998.