Determining the slope between relevant 2d objects

Hello all, included I have my post processed image where I've done a lot of things to it, but basically got it to this post watershed state where the edges are quite segmented.
The idea here is I want to take the slope of the objects, then be able to draw some sort of conclusion from it. For example, if I were to draw a slope along the right side set of objects, would I get a regular gradual slope, or something more like a spline curve?
Main questions:
1. How do I extract the x-y coordinates from those identified objects?
2. Is it possible to draw a 'best fit line' of sorts between the right hand objects (ignoring the ones on the left?)
Thanks!

1 Comment

jonas
jonas on 30 Jun 2018
Edited: jonas on 30 Jun 2018
How did you identify the objects? Can you post the code or a sample code?
From the name of the file I assume you used CC=BwConncomp. The output of that function includes a field CC.PixelIdxList, where the connected pixels for each object are stored.

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Answers (1)

Why not take the points and use poly2mask() to create a solid binary image mask from them?
Then you can call bwperim() or bwboundaries() to get the boundary/outline coordinates for every adjacent pixel.

2 Comments

I'll try this out, thank you!
Lets say I wanted to grab four points:
(Smallest x value, corresponding y value)
(Corresponding x value, smallest y value)
(Corresponding x value, highest y value)
(Highest x value, corresponding y value)
First off, how do I extract those particular numbers from the matrix containing the image? Secondly, do you think that would draw a box around my object that I could take the area of, and then try to work from there?
Kinda going off of the image in:
Also, is the xi and yi values given in:
BW = poly2mask(xi,yi,m,n)
Are these arrays that I pass in those values that I want?

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Release

R2017a

Asked:

on 29 Jun 2018

Edited:

on 3 Jul 2018

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