Summary by TwinMind · 1h 24m 9s
Summary by TwinMind · 1h 24m 9s
Lecture 1: Introduction and fast-forward preview of all topics - Part 1
Lecture 1: Introduction and fast-forward preview of all topics - Part 1
MIT OpenCourseWare
MIT OpenCourseWare
Course Introduction and Philosophy
- Instructor: Ramesh Raskar, MIT Media Lab Camera Culture group
- Course numbers: MAS 131 (undergraduate), MAS 531 (graduate)
- Equipment value: $50,000-$60,000 worth of cameras and imaging equipment
- Core philosophy: Pure digital cameras are "extremely boring" - focus on computational approaches beyond traditional photography
Rolling Shutter Effect Example
- iPhone camera capturing aircraft propeller creates curved blade artifacts
- Demonstrates line-by-line sensor readout vs snapshot assumption
- Rolling shutter reads one line at time due to bandwidth constraints in cell phone cameras
- Opens question: How will photographers exploit future camera artifacts for artistic purposes?
Computational Illumination Techniques
- Shower curtain photography: Using programmable flash to see person behind translucent barrier
- Single photodetector + projector system: Turn on 1 million projector pixels sequentially, record 1 million measurements
- Creates 4D relationship between projector pixels and camera pixels (10^12 measurements)
- Applications: Reading opponent's cards across table using light transport inversion
- Limitation: Requires placing projector in target location
Camera Market Evolution
- 2008-2009: ~1 billion cameras sold annually
- 2001-2002: Zero cameras sold embedded in mobile phones
- Zero to 1 billion cameras in 6 years represents massive market shift
- Camera distribution breakdown:
- Largest: Mobile phones (pink segment)
- Optical mice: ~100 million (20x20 or 32x32 pixels, 1000-2000 Hz)
- Digital/video cameras
- Gaming applications
- Security (very small sliver)
3D Imaging Challenges
- Current 3D cameras cost $10,000+, limited quality
- Time-of-flight demonstration: People in green (front), others in back
- Market driven by gaming consoles (PlayStation, Xbox) for gesture interaction
- Technical challenges:
- Active light compensation for ambient scenes
- Multi-view geometry stitching
- Subsurface scattering in materials
- Specular/dark objects problematic
Multi-Aperture Camera Demo
- 25 separate cameras in single chassis
- Software-based refocusing by shifting/combining images
- Cost: $20,000+ from Viewplus, up to 30-60K for advanced versions
- Demonstrates focus-based depth extraction using baseline between cameras
Biological Vision Systems
- 8 categories of successful biological vision systems
- Scallop eyes: Mirror-based (concave mirror + detector) vs lens-based
- Human vision: Single-chambered with lenses (small subset of possibilities)
- Future cameras could explore other biological architectures
Course Structure and Grading
- Undergraduate (131): 3 assignments, simplified midterm
- Graduate (531): 4 assignments, full midterm
- Grade breakdown:
- Assignments: 40%
- Final project: 30%
- Midterm: 20%
- Class participation: 10%
- Best project award available
- Last year: 3 projects → SIGGRAPH/ICCV papers, 2 projects → multi-hundred thousand dollar research initiatives
Course Tracks and Prerequisites
- Software-intensive track: GUI-based tools
- Software-hardware track: Programming (OpenCV, MATLAB, C++, etc.)
- Critical skill: Ability to think in 3D
- Helpful but not required: Linear algebra, signal processing, image processing
- Assignment structure: 60-70% accessible to all backgrounds, final 20-30% requires advanced knowledge
- Performance normalized based on student background
Course Focus Areas
- Photography: Higher-dimensional imaging (light fields, thermal, range cameras)
- Active Computer Vision: HCI applications, robotics, tracking, segmentation
- Scientific Imaging: Compressive sensing, wavefront coding, deconvolution, tomography
Three Themes of Computational Photography
- Epsilon Photography: Generalized bracketing (HDR, panorama, focus stacking)
- Coded Photography: Reversible encoding of scene information, feature-revealing cameras
- Essence Photography: High-level scene understanding beyond pixels
Thermal Imaging Applications
- Sports analysis example: Cricket ball impact detection (bat vs pad)
- Current cost: Several thousand dollars
- Goal: Reduce to consumer camera prices ($500 in 5 years)
- Guest: Mathias from Redshift thermal imaging company
Upcoming Conference Opportunity
- 2nd International Conference on Computational Photography
- Location: MIT, last week of March
- Paper deadline: November
- Organized by Raskar, Kutulakos (Toronto), Fergus (Colorado)
- Industry interest: Nokia, Samsung, Canon, HP research groups
Course Logistics
- Classes end December 4th (week before final exam period)
- Friday happy hour continuation at Hotel Charles
- Guest lectures and online discussions
- Class notes assignment for credit students
- Listeners encouraged to participate and contribute expertise
