290 likes | 482 Views
Multi-View Geometry. Review: Pinhole Camera. Review: Perspective Projection. Review: Perspective Projection. Points go to Points Lines go to Lines Planes go to whole image or Half-planes Polygons go to Polygons. Perspective cues. Perspective cues. Perspective cues.
E N D
Review: Perspective Projection • Points go to Points • Lines go to Lines • Planes go to whole image or Half-planes • Polygons go to Polygons
Review: Intrinsic Camera Parameters Y M Image plane C Z v X Focal plane m u
Review: Extrinsic Parameters Y M Image plane Y C Z v X X Z Focal plane m u By Rigid Body Transformation:
Recovering 3D from images • What cues in the image provide 3D information?
Visual cues • Shading Merle Norman Cosmetics, Los Angeles
Visual cues • Shading • Texture The Visual Cliff, by William Vandivert, 1960
Visual cues • Shading • Texture • Focus From The Art of Photography, Canon
Visual cues • Shading • Texture • Focus • Motion
Visual cues • Shading • Texture • Focus • Motion • Shape From X • X = shading, texture, focus, motion, ...
3D World Points • Camera Centers • Camera Orientations Multi-View Geometry Relates
3D World Points • Camera Centers • Camera Intrinsic Parameters • Image Points Multi-View Geometry Relates • Camera Orientations
Stereo scene point image plane optical center
Stereo • Basic Principle: Triangulation • Gives reconstruction as intersection of two rays • Requires • calibration • point correspondence
Stereo Constraints p’ ? p Given p in left image, where can the corresponding point p’in right image be?
Epipolar Line p’ Y2 X2 Z2 O2 Epipole Stereo Constraints M Image plane Y1 p O1 Z1 X1 Focal plane
P p p’ O’ O From Geometry to Algebra
P p p’ O’ O From Geometry to Algebra
Linear Constraint:Should be able to express as matrix multiplication.