lens distortion model

topics/01_cameras/index.md

@@ -228,7 +228,7 @@ There are plenty of lens distortion models, with varying complexity and number o
 
 $$
 \begin{cases}
-u_u = u_{cd} + (u - u_{cd})\alpha
+u_u = u_{cd} + (u - u_{cd})\alpha\\
 v_u = v_{cd} + (v - v_{cd})\alpha
 \end{cases}
 $$