how can i measure the longest point of my lightning image?

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Neptune16 2019-4-8

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评论： Neptune16 2019-4-29

采纳的回答： Image Analyst

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Neptune16 2019-4-8

编辑：Neptune16 2019-4-8

no, I mean is there any automatic methods that the code will find the longest point as I mark with orange colour above.

Matt J 2019-4-8

编辑：Matt J 2019-4-8

The straight line distance from red to orange, or the distance when walking along the lightning fork? If the latter, there are several implementations of Dijkstra's algorithm on the file exchange

https://www.mathworks.com/matlabcentral/fileexchange?q=Dijkstra%27s+Shortest+Path

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Image Analyst 2019-4-8

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One way to find the longest spine might be to compute the skeleton and endpoints with bwmorph(). Then compute distance between all identified endpoints with bwdistgeodesic(). See Steve's Image Processing blog

Then find out which pair of endpoints had the longest distance.

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Neptune16 2019-4-29

hello and good day, sir @imageanalyst. I have posted a new question 5 days ago. I would like to ask you a favour to help me with it. kindly please see the latest question I've asked in my profile. thank you for your time and consederation.

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darova 2019-4-8

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longest_skeleton.m

Draw black (0,0,0) line you want to calculate the length

See attached script

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Image Analyst 2019-4-9

If you're going to draw a black line with paint, then you might as well use imfreehand() in MATLAB. I think he was looking for an automatic way, like me (below) or Matt J (above in comments section) suggested. That said, sometimes it's more time effective to employ user-assisted image analysis than trying months or years to get an automatic method (luckily this application won't take anywhere near that long).