Posted by
Michael Schmid on
Jan 14, 2015; 6:49pm
URL: http://imagej.273.s1.nabble.com/Touching-particle-accurate-counting-tp5011214p5011217.html
Hi Al Menia,
maybe you can improve the situation by avoiding the shadows, i.e., by measuring backscattered electrons instead of secondary electrons?
Nevertheless, the 'dense' example will be difficult. Also the white particles are a problem, they hide some of the diamonds.
By the way, your sample images have only 4 bits resolution (16 gray levels), maybe due to conversion to an RGB .png file. This makes processing more difficult than necessary.
Maybe your SEM has some output format that retains the full image data, or there is some plugin (BioFormats?) that can read the native data format of the SEM.
Michael
________________________________________________________________
On Jan 14, 2015, at 18:02, Al Menia wrote:
> Hi,
>
> I am desperately trying to find an automatic way to count diamonds (approx
> 100 um size) on a metallic substrate on SEM imaging. The problem is that
> they are sometimes overlapping, making them hard to separate, even by using
> the watersheding tool. (you'll see very big parts not affected by this tool)
> The method I use is not very accurate:
> - gaussian blur or substrack background (sometimes it works better)
> - tresholding
> - watersheding
> - analyse particle (area 200-infinite, circularity 0.35-1.00)
>
> There are around 620 diamonds in the dense onem and 240 in the less dense
> one. I can only manage to reach a 10% accuracy in the counting, but I would
> like to reach 1%.
>
> Does anybody knows a better way to do this, or knows a good plugin for this
> kind of work?
> A good thing would be to be able to force the watersheding above a given
> area, so that I don't have big agglomerates, but I don't know if this
> already exists...
>
> Thanks,
>
>
> <
http://imagej.1557.x6.nabble.com/file/n5011214/dense.png>
> <
http://imagej.1557.x6.nabble.com/file/n5011214/low_density.png>
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