Detecting curves from binary image?

I am trying to detect curves with a pre-determined shaped from a dataset. The input image will be similar to the following picture:

I want to find a line through the left-most and right-most points, as roughly indicated in the following picture:

So far, I can imagine two ways to get this result:

• First find a way to extract the left-most points and right-most points and using a 3rd/5th degree polynomial or a hyperbolic sine fit through these points.
• Using something like a hough transform but applying it for curved lines.

So far, I have not found a good way to get the results I need, also caused by the fact that the data set is quite large [8890x1312] (above images are stretched in the x direction), making it extremely slow to loop over each pixel.

Do you guys have any ideas to tackle this problem?

[Zihan Wu]

Hi Sebbe,

I have the same problem with yours. How did you solve this problem in the end?

Thank you!

[Image Analyst]

He accepted the answer below so I assume that is what he used. If boundary() is not working for you, then please post your image in a new question.

Answer 1

[Image Analyst]

Try boundary()