Re: Analyse particles: counting eggs query

Posted by Bill Christens-Barry on Sep 16, 2005; 5:43pm
URL: http://imagej.273.s1.nabble.com/Analyse-particles-counting-eggs-query-tp3704847p3704851.html

Amy,

Do you have a sample image I can look at? Several ideas come to mind:

1) Hough transform, which is used to detect circular objects;
2) Correlation-based approach, with spatial filtering to select for desired size ranges;
3) Good old particle counting as you tried, but with some size-selective restrictions.

A lot will depend on the composition of the images - contrast, brightness, etc. Black-on-white is
probably good. It may be that you can get images that are better (for analytical purposes) by
playing with the spectrum of you light source, polarization, etc. I wonder if these eggs fluoresce
under UV.

Also, do clumping eggs clump as monolayers? If so, then you basically have an image in which you
might be able to classify eggs by their maximum height, by acquiring images using narrow depth-
of-focus and focused at various heights.

What kind of imaging was done? Can you describe the camera, illumination, microscope, etc?

Cheers,

Bill Christens-Barry

On Fri, 16 Sep 2005 17:18:03 +0100, Amy Mikhail <[hidden email]> wrote:

>Hello all,
>
>I've recently been using the image J "analyse", "analyse particles"
>function to count mosquito eggs (digital photo taken of black eggs on
>white filter paper).
>
>One difficulty is that the eggs tend to stick to each other, and often
>appear lying side by side.  In this instance, Imaje J counts all the eggs
>that are not separate as one.
>
>Manually separating the eggs out without damaging them is quite difficult
>and very time consuming.  Luckily the eggs do not vary much in size , so
>to overcome this problem, I have worked out the size range (in pixels) of
>an average single egg (9 - 22 pixels).  I carry out 3 counts:
>
>1. < 9 pixels
>2. 9-22 pixles
>3. > 22 pixels
>
>Particles counted in the first range are too small to be eggs and are
>probably dust / artifacts (large artefacts are removed from the photo
>prior to processing).  Particles in the second range are all the eggs that
>have been counted singly, while particles in the 3rd range are eggs that
>are stuck together and have been counted incorrectly.  To get a total
>(more accurate) count,  I use this formula:
>
>Range 2 Count + (Range 3 total area / range 2 mean particle area).
>
>(Areas are in pixels - means are taken from each photo to account for
>differences in zoom etc)
>
>So here is my query; currently I am using an excel sheet to compute the
>formula - I add the necessary results from Image J manually to the excel
>sheet.  Would it be possible to feed the Image J results I need directly
>into the excel sheet?  If so how would I do this?
>
>BTW we are trying to set up this system to use in experiments where large
>numbers of egg papers will be processed on a daily basis (by various
>people).  Using image J as opposed to counting manually is already a vast
>improvement (both time-wise and in terms of human error), so what I'm
>after is a bit of fine tuning to further expedite the process.
>
>Any advice / help on this would be greatly appreciated...
>
>Thanks,
>
>Amy.
>
>
>
>-------------------------------------------
>Amy Mikhail
>Research student
>University of Aberdeen
>Zoology Building
>Tillydrone Avenue
>Aberdeen AB24 2TZ
>Scotland
>Email: [hidden email]
>Phone: [phone] (lab)