  This article presents an algorithm for the evaluation of organelles'
movements inside of an unmodified live cell. We used a time-lapse image series
obtained using wide-field bright-field photon transmission microscopy as an
algorithm input. The benefit of the algorithm is the application of the R\'enyi
information entropy, namely a variable called a point information gain, which
enables to highlight the borders of the intracellular organelles and to
localize the organelles' centers of mass with the precision of one pixel.
