Figure 5

Transforming the rectangle ABCD to a quadrilateral A'B'C'D'. This is the geometry of transforming the TV screen content to desired dimensions of the reference image. Rectangle ABCD must be transformed into the quadrilateral A'B'C'D'. The transformation problem becomes the problem of finding the coordinates of the point G' which corresponds to an arbitrary point G from the rectangle. The point G is on the line EF which should be transformed into the line E'F', with the assumption that the lines are preserved in this transformation.