Shift-and-add is an approach employed to mitigate the phenomenon of
resolution degradation in images acquired through a turbulent medium. Using
this technique, a large number of consecutive short exposures is registered
below the coherence time of the atmosphere or other blurring medium. The
acquired images are shifted to the position of the brightest speckle and
stacked together to obtain high-resolution and high signal-to-noise frame. In
this paper we present a highly efficient method for determination of frames
shifts, even if in a single frame the object cannot be distinguished from the
background noise. The technique utilizes our custom genetic algorithm, which
iteratively evolves a set of image shifts. We used the maximal energy of
stacked images as an objective function for shifts estimation and validate the
efficiency of the method on simulated and real images of simple and complex
sources. Obtained results confirmed, that our proposed method allows for the
recovery of spatial distribution of objects even only 2% brighter than their
background. The presented approach extends significantly current limits of
image reconstruction with the use of shift-and-add method. The applications of
our algorithm include both the optical and the infrared imaging. Our method may
be also employed as a digital image stabilizer in extremely low light level
conditions in professional and consumer applications.Comment: 8 pages, 4 figure
