From Perspectivities to Perspective Collineations
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چکیده
Given distinct planes π and π′ in extended Euclidean space E3, and a point O on neither plane, the associated one-point projection with center O maps π bijectively onto π′. That’s a simple fact, but from the standpoint of real-world one-point projections such as perspective drawing or photography, this map, called a perspectivity, is actually a bit strange. To see why, we first review three types of practical, one-point projections in Figure 1.
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