Ridge Detection



I am trying to apply ridge detection plugin on an image to get the length of random fibers, problem i am facing is that even i set the scale or dosent set the scale the length values remains the same. It there any mistake i am doing ?
Would be nice to find some solution to it.


Hello @faruuk,

Can you please post here a sample image so we can reproduce the behavior?



In lieu of having a dataset from you to run… I tried with the built-in Blobs image sample… and I got the same output you were describing. Even after using Set Scale to rescale the image - the calculations from Ridge Detection were all in pixels. Perhaps @twagner can provide some insight on this??

It might be that you just have to do some post-processing to scale your datasets after calculation…



Hi mate,
Kindly find attached image. I have set the scale in it. You can ofcourse remove the scale and test it .The original scale is 1pixel is equal to 15micrometer.



Hi, thanks for taking a look at my post. Kindly find attached image, i had to save it as jpeg since tiff was not uploading. The scale for this image = 1pixel = 15μm
In response to you idea that some post processing might be required, since the values with and without scale are same , so post processing will result in same values for both of them…thats what i perceives .

kind regards



Dear @faruuk and @etarena,

By looking at the code it seems the calibration in the released version of the plugin is not taken into account. @twagner already took care of it, but he has not released the fix yet.


Thanks mate, Now i am wodering if there is any other way of measuring the lengths of my fibers?


Dear @faruuk,

sorry for the late reply, I was on vacation. I’ve released a new version of the ridge detection plugin (please updadte via update site).



I am using the ridge detection plugin to quantify actin filament branching (phalloidin stain) in HeLa cells. Can someone please explain to me how to interpret the “junctions” data output summary? I do not understand what the numbers in the X and Y column represent. I would like to use this plugin to count the number of total junctions in the cell at bare minimum and ideally, I would like to use this plugin to count the number of branches per actin filament.