I am trying to find the intersection points in images like the one posted below. The intersections I'm trying to find are circled in red in the image below it.
My most succesful approach:
- Thin the image
- Perform a Hough transform, peak identify, and back project
- Identify peaks in the back projection and select those as intersection points
- If there are too many peaks(I say 4 is too many), go to a smaller section of the image and repeat the above steps
Obviously a large problem here is that the Hough transform for detecting lines isn't supposed to detect curves. I thought zooming in on points of interest might fix this, but it has not. Some curves are just still too sharp, and if you zoom in too far the transform doesn't have enough data to make accurate calculations of where lines are.
I've also tried some local feature detection, such as corner detection, to find the intersections. Local features fail miserably, and there are some images to explain why that is as well (although I am currently toying with another approach using gradients; will update post after I implement it).
The white curve isn't an intersection, but the blue and yellow curves obviously form an intersection. The curves, however, have a section of nearly identical local features when converted into a binary image. Any suggestions how to find these intersecting points would be greatly appreciated!