EDIT: Ok… For anyone wondering how the Trapezoidal parameters work here’s what I have figured out:
The X and Y size is your original shape. so 4 by 4 gives you a square 4 by 4.
The Trap. delta dim is the difference between the top side and the bottom side. So Trap. delta dim = 1 means that the top is 4-1 and the bottom is 4+1.
So now you have a trapezoid with the small side (the top) equal to 3 and the long side (bottom) equal to 5. The height of the trapezoid is still the same as the original shape (in our example 4).