Posted by
Jeremy Adler-2 on
URL: http://imagej.273.s1.nabble.com/Find-missing-spots-in-a-grid-of-spots-tp5019879p5019971.html
A spatial correlation image would avoid the repeated rotations and projections,
the maxima in a cross correlation between two image shows the offset and in a self correlation gives the spacing and direction of repeated structures.
Is there a plugin or command ?
Jeremy Adler
-----Original Message-----
From: ImageJ Interest Group [mailto:
[hidden email]] On Behalf Of ard
Sent: den 31 januari 2018 15:54
To:
[hidden email]
Subject: Re: Find missing spots in a grid of spots
Hi Gabriel,
Unless I grossly misunderstand you, I'm afraid that is not exactly what we are after, as we are after the perfect grid with all missing dots put back in and stray blobs removed. This grid is generated by drawing circles in an empty window, by the way.
Imagine a perfect honeycomb (hexagonal) with a dot on every corner and a dot in the center of each honeycomb cell. Now erase all edges so only the dots are left. Then randomly remove some dots. Now degrade each remaining dot a random number of pixels around the perimeter. Then shift and rotate the whole image across an arbitrary distance and angle < 30 degrees. Add noise.
Invert the image. Add noise again.
In the cleaned-up image below, which is only 1 degree off vertical, there are two dots missing (3rd column 9th row and 4th column 8th row; near the latter is a strayblob, not a dot). Both the missing dots and the stray blob could easily be identified by an X- and Y projection. Analyze Particles, with the proper size and circularity will find the most dots correctly, but of course it will not find the missing dots and it is confused by the stray dots too.
We are asked to indicate which dot(s) have vanished and which are not dots but blobs, so as to generate the 'perfect' honeycomb dot pattern again.
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http://imagej.1557.x6.nabble.com/file/t188556/dots.gif>
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