  We present a new pipeline developed to detect and characterize faint
astronomical companions at small angular separation from the host star using
sets of wide-field imaging observations not specifically designed for High
Contrast Imaging analysis. The core of the pipeline relies on Karhunen-Lo\^eve
truncated transformation of the reference PSF library to perform PSF
subtraction and identify candidates. Tests of reliability of detections and
characterization of companions are made through simulation of binaries and
generation of Receiver Operating Characteristic curves for false positive/true
positive analysis. The algorithm has been successfully tested on large HST/ACS
and WFC3 datasets acquired for two HST Treasury Programs on the Orion Nebula
Cluster. Based on these extensive numerical experiments we find that, despite
being based on methods designed for observations of single star at a time, our
pipeline performs very well on mosaic space based data. In fact, we are able to
detect brown dwarf-mass companions almost down to the planetary mass limit. The
pipeline is able to reliably detect signals at separations as close as $\gtrsim
0.1 "$ with a completeness of $\gtrsim 10\%$, or $\sim 0.2"$ with a
completeness of $\sim 30\%$. This approach can potentially be applied to a wide
variety of space based imaging surveys, starting with data in the existing HST
archive, near-future JWST mosaics, and future wide-field Roman images.
