Simple HSB measurement

Posted by Julie Colpitts on Jan 21, 2016; 9:09pm
URL: http://imagej.273.s1.nabble.com/Simple-HSB-measurement-tp5015427.html

Hi there,
I am looking to measure the hue, saturation and brightness of manually selected areas on RGB images. I have been playing with images of known colour in order to verify that any output from ImageJ matches my expectations. After converting the image to an RBG stack, the 'mean gray value' of each slice corresponds to my expected red, green and blue values. However, when I follow the same procedure after converting to an HSB stack, the values do not correspond with my expected hue, saturation and brightness values.
What I am wondering is if there is an unusual scale that any or all of the hue, saturation and brightness values are measured on in ImageJ (or if the mean gray value of each of these stacks is actually a viable way to measure HSB), and if there is a simple, straightforward way to measure the mean of each of those values for a selected area on an image.
Any insight is greatly appreciated.
Thank you very much,
JC