Re: Thresholding help

Posted by Fabrice Senger on Oct 29, 2008; 8:50pm
URL: http://imagej.273.s1.nabble.com/Thresholding-help-tp3694620p3694622.html

Quoting Justin Walker <[hidden email]>:

> I have a series of images of liquid droplets, which have very poor
> contrast with the surrounding phase, due to the similarities in their
> index of refraction.  I get enough contrast in my images to clearly see
> the droplets, however, I can't pick them out with the threshold because
> there is a slight gradient in the brightness of my lighting.  Link to a
> sample image is below:
>
> http://www.chejrw.com/forum/test.tif
>
> Does anyone know of a way I can manipulate this image to be able to use
> the 'measure particles' plugin to get the droplet sizes?  I can clearly
> see the droplets, so surely there must be a way to make the computer
> see them.
>
> Thanks everybody
>
> - Justin Walker

As far I can see in your images, you can see the "contour" of the droplets.
If you invert your image, this "contour" should appear bright in a  
dark background.

This should help.

Fabrice.