ECE 449CS 443: COMPUTER VISON LECTURE 3

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ECE 449/CS 443 COMPUTER VISON LECTURE 3

• Pinhole cameras
• Camera with lenses
• Sensing
• Reading
• Cameras (Chapter 2)
• For next time Radiometry (Chapter 1)

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They are formed by the projection of 3D objects.
Images are two-dimensional patterns of brightness
values.
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Animal eye a looonnng time ago.
Photographic camera Niepce, 1816.
Pinhole perspective projection Brunelleschi,
XVth Century. Camera obscura XVIth Century.
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Pompei painting, 2000 years ago.
Brunelleschi, 1415
Van Eyk, XIVth Century
Massaccios Trinity, 1425
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Pinhole Perspective Equation
NOTE z is always negative..
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Affine projection models Weak perspective
projection
is the magnification.
When the scene relief is small compared its
distance from the Camera, m can be taken
constant weak perspective projection.
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Affine projection models Orthographic projection
When the camera is at a (roughly constant)
distance from the scene, take m1.
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Planar pinhole perspective
Orthographic projection
Spherical pinhole perspective
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Diffraction effects in pinhole cameras.
Shrinking pinhole size
Use a lens!
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Lenses
Snells law n1 sin a1 n2 sin a2
Descartes law