lec13

lec13 - Lecture 13: October 6, 10 HW3 due today Exam 1, Oct...

This preview shows pages 1–5. Sign up to view the full content.

USC CS574: Computer Vision, Fall 2010 Copyright 2010, by R. Nevatia 1 Lecture 13: October 6, 10 • HW3 due today • Exam 1, Oct 13, class time – Close book, material covered listed in Oct 4 class slides • Last Class – Structure from motion • Number of needed matches • Affine/Projective ambiguities • Two camera case • Today’s objective – Structure from motion sequences

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
USC CS574: Computer Vision, Fall 2010 Copyright 2010, by R. Nevatia 2 Affine Cameras • Affine projection matrix is 2 x4 matrix which can be written as – Note: p ij and P j are both non-homegeneous coordinates A i is an arbitrary 2x3 matrix of rank 2, b i is arbitrary 2 vector – Some examples (from section 2.3) •G i v e n m views and n points, 8 m +3 n unknowns, 2 mn equations, we can solve given large enough m and n.
USC CS574: Computer Vision, Fall 2010 Copyright 2010, by R. Nevatia 3 Affine Ambiguity • Solution is ambiguous up to an affine transformation • Removing 12 unknowns due to affine ambiguity, for 2 images, we need only 4 points for affine reconstruction 2 mn >= 8 m +3 n – 12, for m =2, n = 4

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
USC CS574: Computer Vision, Fall 2010 Copyright 2010, by R. Nevatia 4 Affine Structure from Two Images using inhomogeneous coordinates; A is 2x3, b is a 2 vector M= ( A b ) , M’= ( A’ b ) Choose: Any affine transformation of M and M’ will also work,
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/23/2010 for the course CS 574 taught by Professor Ramnevatia during the Fall '10 term at USC.

Page1 / 14

lec13 - Lecture 13: October 6, 10 HW3 due today Exam 1, Oct...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online