Posted by
Robert Baer on
URL: http://imagej.273.s1.nabble.com/Infrared-filter-on-RGB-image-tp5001401p5001416.html
On 1/14/2013 12:36 PM, nisha wrote:
> Dear Dr. Baer,
>
> I am extremely sorry, I made a huge mistake in explaining my doubt.
> Actually, I have a color image (captured from an ordinary camera) on which I
> want to produce an effect as if during the time of capture, the object was
> exposed to some wavelength. For example, while capturing an image, say the
> object was exposed with a wavelength of 630nm (red color) or an infrared
> wavelength.
>
> I want to induce such effects on images. I am really sorry, I used wrong
> words in expressing my doubt.
>
> Thanks in advance!
>
> Nisha
>
>
Perhaps I am still missing your question, but let me try saying it this
way. In "theory" an RGB color image contains only information from the
visible part of the spectrum and NO information about infrared
emission. Depending on the physical collection method, however, this
theoretical assumption may not be the case. I imagine you are concerned
that your images contain influence from IR emissions.
However, you can not estimate how much IR contamination there is in your
images with software alone (ImageJ or any other software). To estimate
IR contamination you must also make direct, physical measurement of IR
cross-talk under conditions where there is no primary image signal .
Such crosstalk may vary with conditions (say excitation intensity), and
so it must be measured under conditions appropriate to you measure.
That is, you need appropriate positive and negative controls for IR
crosstalk.
The only way to know how much contamination of your images comes from IR
emissions is to measure IR crosstalk physically. If you construct some
sort of library specifying how much IR emissions affects each of your
RGB channels, you may THEN be able to subtract out its effect.
You CANNOT estimate how much IR has contributed to your sample images
from just the images.
Hope this makes the issue more clear,
Rob Baer
--
__________________
Robert W. Baer, Ph.D.
Professor of Physiology
Kirksille College of Osteopathic Medicine
A. T. Still University of Health Sciences
Kirksville, MO 63501 USA
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