How to calculate the total length of all the lines in this image (with grid)?

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Hello,
Is there a way to calculate the total distance/length of all the red lines in this image (only red lines)?
Those red lines are like trajectory, and each cyan grid's edge can be consider as 1 unit.
[Calculating each line's length and adding them all up isn't going to work because later on i will have more red lines :( ]
Thank you in advance!!!

Answers (1)

Benjamin Thompson
Benjamin Thompson on 15 Aug 2022
Edited: Benjamin Thompson on 15 Aug 2022
You can use colorThresholder to help isolate the red pixels and then simply count all of them in the resulting mask image using the sum function. colorThresholder generates script code which I have attached, with a small manual edit to get just the BW mask image as the output. Apply a scale factor to the result if your red lines are wider than one pixel.
sum(redPixelMask(A), 'all')
ans =
114805
  2 Comments
Bunnyo
Bunnyo on 18 Aug 2022
Hi, thank you for your answer! I'm kind of confused on this "if your red lines are wider than one pixel" part. How should i apply this scale factor?
Benjamin Thompson
Benjamin Thompson on 18 Aug 2022
A pixel count is more a measure of area so if your lines are 2 pixels wide, the measurement will be 2 times too large as a distance estimate.

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