Posted by
Henry Barwood on
Dec 13, 2005; 6:13pm
URL: http://imagej.273.s1.nabble.com/Quick-Help-Pixel-Subtraction-tp3704239p3704243.html
I tried to distinguish "hot spots" from "hot pixels", apparently
unsuccessfully. My samples are petrographic slides that are contaminated
with particles of alumina polish. The particles luminesce a brilliant,
bright green, but are of irregular size and dimension. I only want to modify
the "hot Spots" not the remaining image, hence, I'm reluctant to use any
other noise reduction or background subtraction filters.
When I remove the hot spots using the threshold technique it leaves a
completely black spot in place of the bright green spot. I would like to
replace the removed area with a less conspicuous area that more accurately
matches the surrounding image. Don't know if I explained that properly, but
I'm sort of struggling for terminology here!
Henry
-----Original Message-----
From: ImageJ Interest Group [mailto:
[hidden email]]On Behalf Of
Gabriel Landini
Sent: Tuesday, December 13, 2005 11:53 AM
To:
[hidden email]
Subject: Re: Quick Help? Pixel Subtraction
On Tuesday 13 December 2005 17:36, Henry Barwood wrote:
> I tried out the "simple" method below and found it to work fairly well
with
> some CL images I have. Only had two problems that turned up. When the
> thresholded image is subtracted (to eliminate "hot spots" from sample
> contamination) it leaves disconcertingly dark "holes" in the image. Is
> there: 1)A simple way to "blur" the image to be subtracted so that it
> feathers into the surrounding area?
If the noise is relegated to a single pixel, why do you want to subtract a
value from the neighbouring pixels?
Try the other methods, they replace the hot pixels with the average or
median
of the neighbours.
> 2)A way to cause the thresholded image
> to take on a more neutral value so that it is not so obvious in the
> processed image?
Sorry I don't understand what that means. Thresholds are yes/no only...
Cheers,
Gabriel