Slope of multiple lines in a jpeg image

Hello everyone,

I have a simple question. I want to know the slope of multiple lines in an image. I wanted to try polyfit but I didn't manage to separate the corresponding points to calculate the slope.

Any suggestions ?

[Michael Haderlein]

Is your question about image analysis (finding lines in an image) or about getting the slope of a line?

[Image Analyst]

And if it's about finding some coordinates in an image, wouldn't it make sense to post the image?

[Paulo]

Yes, I have to find the lines and then I have to find the slope for the corresponding lines. I posted the image.

I have tried using im2bw and then I tried to find the changes from 0 to 1 for every column. I saved these changes in a matrix, but I didn't manage to get the slope of the corresponding lines.

Answer 1

[Image Analyst]

It would have been best if you just attached the image in the first place, don't you think. It was really easy so I just went ahead and did it all for you. See attached demo, below the image it creates:

For blob #1, the slope = 0.198371
For blob #2, the slope = -0.465403
For blob #3, the slope = 1.088155
For blob #4, the slope = -1.784847
For blob #5, the slope = 8.596451
For blob #6, the slope = 8.703217
For blob #7, the slope = -1.780951
For blob #8, the slope = 1.088187
For blob #9, the slope = -0.463639
For blob #10, the slope = 0.200490

[Paulo]

Thank you very much ! I'm very grateful!

Answer 2

[Image Analyst]

See my polyfit demo. One of the fits is does is for a line.

[Paulo]

Thank you very much for your response ! I really appreciate it. It's very helpful, but I still have problems associating the corresponding values for the polyfit function. But still Thank you!