Vanishing Point and Horizon Line

Precisely because it is limited to plane transformations, it is particularly easy to calculate the limits of coordinates $x$ and $y$ through transformation (9.36) as

$$\begin{array}{rl} \lim_{x\to\infty}\mathbf{H} (x,y,1)^{\to... ...left( \frac{h_1}{h_7}, \frac{h_4}{h_7} \right) \\ \end{array}$$ (9.39)

These limits are the image's vanishing points (see Section 9.2.2).