how can i find diagonal line in image?

I have an image which contains canny output of it. now, I want to find diagonal line that exist in top left part of image. do you have any idea?

Answer 1

[Swarooph]

You can use hough transform to detect lines. Once lines are detected, you can use properties such as theta on the houghlines structure to filter your lines compared to a reference line.

Take a look at this example to see how to use hough transform to detect lines in MATLAB.