Projective Transformation
Projective transformations come into play whenever perspective drawings of a scene are required. A projective transformation is defined by four preimage/image pairs of points. The definition is analogous to that of a
similarity, though with eight required points instead of four.
As an example we consider the situation of producing a projective image of a rectangular grid. For this we simply have to draw a rectangular grid and the corners of the desired image. We define a projective transformation by mapping the corners of the rectangular grid to the corners of the image.
 |
Defining a projective transformation |
After this we apply the map to the elements of the rectangular grid. The image of this operation is the desired projected rectangular grid.
 |
The image of the rectangular grid |
See also