Re: Background subtraction operations

Posted by Gabriel Landini on Jan 21, 2006; 12:51pm
URL: http://imagej.273.s1.nabble.com/Background-subtraction-operations-tp3703978p3703980.html

On Tuesday 17 January 2006 09:40, Wang, Junsheng wrote:
> As to the uneven illuminative image stack from X-ray transmission, it is
> difficult to substract a proper backgroud per image. I'm planning to do
> the z-direction median filter and trying to generate a backgroud from
> the stack. Can anybody point me to a plugin which can do this?

Without having any other clues about the problem, I do not understand the
problem. If you have an  uneven exposure of X rays what has the median image
of the stack have to do with the uneven nature of the background?

If you have a pixel which has not been exposed in the majority of the frames
(i.e. there is an object between the xray source and the detector) taking the
median guarantees that one of those pixels will be forming part of the median
image. You would be then use those pixels for "background correction". Is
that the correct way of doing background correction?

Can you just take a shot without the specimen and correct from that image
alone?

Cheers,

Gabriel