OpenCV with Python By Example

Projective transformations

Affine transformations are nice, but they impose certain restrictions. A projective transformation, on the other hand, gives us more freedom. It is also referred to as homography. In order to understand projective transformations, we need to understand how projective geometry works. We basically describe what happens to an image when the point of view is changed. For example, if you are standing right in front of a sheet of paper with a square drawn on it, it will look like a square. Now, if you start tilting that sheet of paper, the square will start looking more and more like a trapezoid. Projective transformations allow us to capture this dynamic in a nice mathematical way. These transformations preserve neither sizes ...