How to find intersection points between a line and polyfit in opencv?

Question

I am currently working on lane detection on opencv. I detected right and left line pixel coordinates for lane in seperate parameters such as:

• left_line_x (= contains pixel x coordinates that belongs left line)

• left_line_y

• right_line_x

• right_line_y

And then created 2 polyfits with them which are;

left_line = np.polyfit(left_line_y, left_line_x, 2)

and same for right.

Because there are many pixel points that I've detected (59168 for only left for example) I want to draw imaginary horizontal lines to the image and then look for intersection points between those lines and line polyfits (left_line).

How can I do this? Especially need help on the intersection part. Thanks in advance.

Answer 1

2 degrees of freedom does not match the inputs given in the original problem. I've assumed 1 degree of freedom for the solution below.

To find the intersection of lines given the output from numpy.polyfit(), try the following:

x0 = -(left_line[1] - right_line[1])/(left_line[0]-right_line[0])
y0 = x0*left_line[0] + left_line[1]