Is the Intersection Point of Two Lines a Cross Product?

[orochimaru]

Hi,
i need enlightenment on this question of mine.

Suppose i have two lines, L and M.
L and M intersect at point X.
Then is X a cross product of L and M?

I read this from a pdf on Multiple View Geometry.
Here the link http://www.syseng.anu.edu.au/~hartley/Papers/CVPR99-tutorial/tut_4up.pdf
the eqn is on pg 8 top right corner slide.

Thanks in advance!

 

[TD]

Yes, that is correct.

For example, take the lines x + y + 1 = 0 and -x + 2y = 0 with vector representations (according to your pdf file) \left( {1,1,1} \right) and \left( {-1,2,0} \right).

The cross product is \left( {1,1,1} \right) \times \left( { - 1,2,0} \right) = \left( {2,1, - 3} \right). Dividing by -3 to get the z-component to equal 1 gives the cartesian intersection point of \left( { - \frac{2}{3}, - \frac{1}{3}} \right)