Posted by
Herbie on
URL: http://imagej.273.s1.nabble.com/Find-missing-spots-in-a-grid-of-spots-tp5019879p5019988.html
Good day Ard,
I have a macro at hand that generates the image I've posted before but
I'm still not perfectly sure about what your colleague likes to see as a
result.
The macro generates an ideal dot grid from the input image. Then it
matches this ideal dot grid to the input image and subtracts it from the
latter.
From the resulting difference image it is quite easy to determine the
coordinates of the missing dots after proper thresholding and particle
analysis.
However, I'm not sure how to treat blobs and debris. A similar approach
as for the missing dots appears possible but requires a definition of
what exactly is to be regarded as a blob ...
If the result achieved with my macro is sufficient, I can provided it
offlist. On my iMac it takes about 350ms to process the provided
1024x1024 sample image.
Regards
Herbie
:::::::::::::::::::::::::::::::::
Am 05.02.18 um 07:35 schrieb ard:
> @ Gabriel,
>
> In this particular case, a 'nice' image, indeed the blob is morphologically
> different from the dots. Many of the images have much more deteriorated
> dots, down to a dozen of pixels, and blobs and dots are hard to separate,
> except for the regularity in their x- and y coordinate increments. We
> measure the x-y centers of gravity and then reconstruct the original grid by
> drawing circles of known size to be used as a mask. Having all centers gives
> a more robust reconstruction of the mask.
>
> @ Herby,
> I did not know that plugin yet and will experiment with it. The result of
> your attempt looks promising. When I can find all dots as clearly
> outstanding from the background as your result, it is easy to find them via
> particle analysis and thus locate the centers. Thanks for pointing me in
> that direction.
>
> Hoping Cornelius also benefits form these answers, I'm off to implement :-)
>
> Ard
>
>
>
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