Variation in brightness & spectral composition within a stack

Posted by Tom_R on Mar 08, 2010; 12:33pm
URL: http://imagej.273.s1.nabble.com/Variation-in-brightness-spectral-composition-within-a-stack-tp3689053.html

Hi Everyone,
I have a bit of a problem I hope you can help me with:

- I have a stack of colour time-lapse JPEGs (approx 2000 in each).
- I convert these to RGB stack
- Within the stack there is daily variation in the brightness and spectral composition which I'd like to remove.
- On each image I have a standard grey-card (reflects 18% of all light).

QUESTION: How exactly can I use this reflectance standard to remove the daily  variation across the stack?

Note, that I don't want to convert to greyscale, as the RGB colour information is essential for object identification (via  process -> binary -> find maxima).

If you have any suggestions, could you please give specific instructions, as I am an ImageJ novice.

MANY THANKS !

Tom