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. 2021 Apr 19;32(9):931–941. doi: 10.1091/mbc.E20-11-0744

TABLE 1:

Cega thresholding values used for experimental data.

Step Optimal values estimated for experimental data How to estimate values Additional considerations for optimal use
Pixel calibration Offset = 2293 and Gain = 71 Estimated from series of dark frames from EMCCD camera (see Materials and Methods). Data must be calibrated before Cega.
Calibration is specific to the camera used.
Stationary model estimation Sliding temporal window median filter = 31 frames. Duration of >95% of moving motors of interest. If tracking particles that move for long periods of time or periodically pause, choose a window size encompassing the duration of >95% of the particles of interest.
Motion model estimation Spatiotemporal gaussian blur = 5 frames Duration that >95% of moving motors remain within 2 adjacent pixels. Smaller temporal kernel provides better computational efficiency.
KL divergence No user defined parameters are required. No user defined parameters are required. Stationary and motion models are used as input.
Connectivity filter 3 connected pixels >0.1 nats Threshold set to 95th percentile of connectivity model. Additive salt noise results in many false positives. This noise is removed before candidate finding by applying a threshold.
LoG filter 3 × 3 neighborhood pixel sum from connectivity filter >5 nats. Threshold set to 95th percentile of LoG model. The LoG image sequence is used to find initial local minima. Then, connectivity image sequence values for these positions are used to threshold local minima appropriately.