1. Lecture 4-1CS251: Intro to AI/Lisp II Seeing is Believing April 27th, 1999

2. Lecture 4-1CS251: Intro to AI/Lisp II Announcements Today’s homework More course project conferences Course project, step 2 –What’s an A? References: At least 12, comments on some Code: Description of system plus 100 lines of code –What’s a C? References: Just 6, no comments Code: 50 lines, no explanation

3. Lecture 4-1CS251: Intro to AI/Lisp II Vision Why is it hard? –3D world on a flat surface –One flat surface many 3D worlds –Like 3 equations in 397 unknowns What is computer vision? –Understanding images –Image processing/pattern recognition

4. Lecture 4-1CS251: Intro to AI/Lisp II What can you do with computer vision? Robots (Passive vs. active sensing) Automation (Working on the line) Inspection Remote sensing Human-computer communication Visual assistants

5. Lecture 4-1CS251: Intro to AI/Lisp II Mimicking Human Vision Fallibility of human vision –Why is it fallible? http://insight.med.utah.edu/Webvision/index.html

6. Lecture 4-1CS251: Intro to AI/Lisp II Human Vision Foveated –Greatest acuity in the fovea –Small (fraction of a mm) –Only has cones Photoreceptors –Rods: Low light vision –Cones: Three flavors –Number of rods/cones: 125,000,000 –Optic nerve fibers: 1,000,000

7. Lecture 4-1CS251: Intro to AI/Lisp II

8. Lecture 4-1CS251: Intro to AI/Lisp II Move that eye

9. Lecture 4-1CS251: Intro to AI/Lisp II Into the Eye...

10. Lecture 4-1CS251: Intro to AI/Lisp II Ocular Cross-Section

11. Lecture 4-1CS251: Intro to AI/Lisp II Through the Opthalmascope

12. Lecture 4-1CS251: Intro to AI/Lisp II A Simple View of the Retina

13. Lecture 4-1CS251: Intro to AI/Lisp II Will the Real Retina Please Stand Up?

14. Lecture 4-1CS251: Intro to AI/Lisp II Things Get Fuzzy After This... How do the images on the retina become part of our visual understanding?

15. Lecture 4-1CS251: Intro to AI/Lisp II What’s the plan? Build on a set of primitives –Edges –Lines –Segments –Regions –Depth –Objects Construct a representation of a 3D scene

16. Lecture 4-1CS251: Intro to AI/Lisp II

17. Lecture 4-1CS251: Intro to AI/Lisp II Threshold

18. Lecture 4-1CS251: Intro to AI/Lisp II

19. Lecture 4-1CS251: Intro to AI/Lisp II Another Edge Finder

20. Lecture 4-1CS251: Intro to AI/Lisp II Histogram

21. Lecture 4-1CS251: Intro to AI/Lisp II Edge Detection What’s an edge? Many kinds of edges Smoothing to aid edge detection

22. Lecture 4-1CS251: Intro to AI/Lisp II Wagon Wheel (From UBC)

23. Lecture 4-1CS251: Intro to AI/Lisp II