Help for a new user to analyze percentage of certain colored pixels in digital image?

Posted by Emily Teng on Jul 22, 2016; 2:46am
URL: http://imagej.273.s1.nabble.com/Help-for-a-new-user-to-analyze-percentage-of-certain-colored-pixels-in-digital-image-tp5016922.html

Hi everyone,
I am completely new to ImageJ.  Just found out about it today and hoping it
is exactly what I need for my research purposes.  I am a PhD student.

I need a method to analyze the percent of coloration of poinsettia plants
over time.  I plan to take digital photos of the top of the canopy over
time and analyze those images.  As I understand it, I could use ImageJ for
this purpose correct?

Taking for example, a red poinsettia - I would need the program to count
all the pixels that are any shade of red (vs green) in the plant.

http://www.ecke.com/poinsettias/bractmeter/

That is what I'm trying to do.  The professor who created that told me he
had someone do programming to count the pixels.  But I'm thinking ImageJ
will be able to do this if I know how to use it?

Can someone tell me
1.  Can ImageJ do this?
2. If yes -  Point me in the direction of how I should go about learning
how to do this?

Thank you in advance for any help and guidance.

Emily

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