collagen fiber

Posted by blast on Jun 16, 2011; 6:44am
URL: http://imagej.273.s1.nabble.com/collagen-fiber-tp3684222.html

Hi I'm new to image j and I want to measure the length, diamter and area fraction of collagen fiber that is taken by a 2 photon micrscopy

1) I dont know if i should do a calibration first? How do I do it and which picture should I use? After calibration, do I stick with the same units because Im worried that the fiber units are way smaller compared to such as meter?

2) When I measure the length, I also want to measure the diameter and I want image J to use both length and diamter to calcualte aspect of ratio for me?

3) I found a link to calculate area fraction  http://chemweb.calpoly.edu/jhagen/Area%20Fraction%20in%20ImageJ.pdf 
but I dont know if the top part or the second part will yield the right results?