Grouping

Grouping or merging localizations is a common procedure to reduce the effects of blinking. Since each molecule is detected multiple times, the position of the molecule is hidden in a scatter of localizations. To make a better estimate of the position of the molecule, the localizations can be grouped/merged into a single point.

See the examples on the right. The left image shows a simulated microtubule, the right image shows a centriole particle. Both, before/after grouping.

To perform a grouping operation, the blinking needs to be characterized for example using the procedure described in photophysics.

The essential parameters to group your data are the dark time and the localization precision.

After obtaining these parameters, use the script photophys_grouping.m to group your localizations.

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smartMerging

smartMerge workflow

1. initial tracking to identify molecule candidates
2. calculate the probability for each localization to be part of a molecule
3. calculate the probability-weighted center of each track
4. generate a photon-weighted 2D histogram

simulated example