| The projective plane |
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| Why do we need
homogeneous coordinates? |
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| • | represent points
at infinity, homographies, perspective |
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| projection,
multi-view relationships |
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| What is the
geometric intuition? |
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| • | a point in the
image is a ray in projective space |
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| image plane (z
= 1) |
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| z |
| x |
| (x,y,1) |
| (sx,sy,s) |
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| • | Each point
(x,y) on the plane is represented by a ray (sx,sy,s) |
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| – | all points on the
ray are equivalent: (x, y, 1) (sx, sy, s) |
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