How can I mount line on image so that computer can track it?

angle measurment

https://mathworks.com/help/images/examples/measuring-angle-of-intersection.html

I tracked this tutorial and faced problem.

In my case, image I want to analyze has unstable horizontal boundary.

That makes computer hard to track horizontal boundary and data gone inexact.

So I drew line on image and let the computer track boundary but computer couldnt.

How can I make straight line that computer can track?

[Jan]

The question is not clear. What does "computer couldnt" mean exactly? Perhaps the problem gets clear, if you post your image.

[hyong suk choo]

I'm sorry, image owner dont want to show the image. I meant when horizontal boundary is tracked, boundary's shape is not a line because of uneven surfcae in image. It is tracked like kind of curved line. This sets crosspoint of two boundary on wrong position and angle is broken. So I wanted to put horizontal boundary manually and I'm stucked.

[Walter Roberson]

Using line() draws on the screen; it does not change what is stored in the variable img .

If you have the Computer Vision toolbox you can use https://www.mathworks.com/help/vision/ref/vision.shapeinserter-class.html

[hyong suk choo]

Thank you! I will try it!

Answer 1

[Tohru Kikawada]

Try to detect lines with houghlines as follows:

https://mathworks.com/help/images/hough-transform.html

It could be applied for imbalanced boundary images.