Edge merging: what could be wrong

What happened?

• somewhere, there is a radius discrepancy
• it happened at only one boundary among two

What happened?

• CCs are valleys; so edges of a CC are Infs;
  
• they need to be extended one pixel, or, re-extracted from the "holes"

What else happened?

• Wrong edges from nb attached CCs.
• Detaching function should take care of nb-FOVs by filling the necessary points in overlaps

When and how to extract bottom?

• If we do it in individual FOVs, then if one top edge is missing, the missing bottom radius can't be obtained through top edges -> has to remain NaN;
• If we do it in main-thread, then how do we trace back to what's inside the valley?
• Conclusion: In individual FOV, at least get the radial position of the missing points