Posted by
Henry Barwood on
Dec 13, 2005; 5:36pm
URL: http://imagej.273.s1.nabble.com/Quick-Help-Pixel-Subtraction-tp3704239p3704241.html
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? 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?
My contaminated images contain intense green spots. Can I extract the green
values from a RGB image and threshold only those areas?
Henry Barwood
Associate Professor of Science, Earth Science
Department of Math and Physics
MSCX 312G
Troy University
Troy, Alabama 36082
[hidden email]
-----Original Message-----
From: ImageJ Interest Group [mailto:
[hidden email]]On Behalf Of
Gabriel Landini
Sent: Monday, December 12, 2005 4:58 PM
To:
[hidden email]
Subject: Re: Quick Help? Pixel Subtraction
On Monday 12 December 2005 20:54, Gary Laevsky wrote:
> Our homemade system has some inherent noise in the PMT, to the tune
> of about 1000 pixels out of 30,000 or so. I'd like to "delete" the
> 255s. In many cases, the next pixel value is about 150, so I'm also
> having some "stretch" issues. If I could just delete the 255s....
Not sure if these 3 options would to what you want, but be aware that these
methods "invent" values for the noisy pixels...
A) simplest:
* duplicate original and call it image1
* threshold the image1 at 255,255
* subtract original-image1 (pixels at 255 will now be 0).