get distance between lines using tangent

Hi, i have a binary image, which it consists of 4 edges, where in the middle of each of the two edges has its centerline. Now, i would like to get the distance between the centerline to the both edges (or thickness), using tangent from the centerline. and every row of the (centered at the centerline) should have the thicness data. I would really appreciate your help. I attached the image as well.

Thanks!

[John D'Errico]

You need to sit down and think about what you need to do. So far, you have stated only a very amorphous set of specs for your job/homework/project.

Define what the real problem is, in terms of mathematics. Is your problem solvable at all? So far, for example, the distance between two tangent lines is almost always zero. So your question makes no sense at all.

Once you have done that, then you can try to turn it into computer code.