  Resolution enhancements are often desired in imaging applications where
high-resolution sensor arrays are difficult to obtain. Many computational
imaging methods have been proposed to encode high-resolution scene information
on low-resolution sensors by cleverly modulating light from the scene before it
hits the sensor. These methods often require movement of some portion of the
imaging apparatus or only acquire images up to the resolution of a modulating
element. Here a technique is presented for resolving beyond the resolutions of
both a pointwise-modulating mask element and a sensor array through the
introduction of a controlled blur into the optical pathway. The analysis
contains an intuitive and exact expression for the overall superresolvability
of the system, and arguments are presented to explain how the combination of
random coding and blurring makes the superresolution problem well-posed.
Experimental results demonstrate that a resolution enhancement of approximately
$4\times$ is possible in practice using standard optical components, without
mechanical motion of the imaging apparatus, and without any a priori
assumptions on scene structure.
