  Incoherent Fourier ptychography (IFP) is a newly developed super-resolution
method, where accurate knowledge of translation positions is essential for
image reconstruction.To release this limitation, we propose a preprocessing
algorithm capable of extracting translation positions of the structure light
directly from raw images of IFP, termed translation position extracting (TPE).
TPE mainly involves two steps. First, the speckle parts mixed in the acquired
intensities, in which the illumination motion is encoded, are isolated by
intensity averaging and division. Then the cross-correlations of the speckle
dataset are computed to determine the shift positions. TPE-IFP improves the
previous IFP by removal of the requirement for prior knowledge of translation
positions. Its effectiveness is demonstrated by obtaining high-quality
super-resolution images in absence of location information in both simulations
and experiments. By further relaxing the practical conditions, the proposed TPE
may accelerate the applications of IFP. What is more, as a preprocessing
approach, TPE might also contribute to the estimation of pattern positions for
the similar speckle-based imaging.
