The dSTORM engine is the collective term for the core of the rapidSTORM software that is not part of the input or output drivers. The dSTORM engine is responsible for converting a vector of input images into a set of localizations, performing the steps of spot detection, spot fitting and spot judging defined in [WolterDiplomarbeit]. While the exact algorithms are out of the scope of this manual, a short summary of the engine operation can be given:

First, the input images are smoothed to reduce the amount of noise present. The local maximums of these noise-reduced images are located and stored as spot candidates, that is, positions where spot positions are likely to be present. The candidates are sorted with the strongest values first in the list and then nonlinearly fitted with the PSF model in the order established by that sorting. Once three successive candidates have failed to be fitted as localizations, the fitting process for the image is aborted.