Applications of the phase transfer function of digital incoherent imaging systems.

The phase of the optical transfer function is advocated as an important tool in the characterization of modern incoherent imaging systems. It is shown that knowledge of the phase transfer function (PTF) can benefit a diverse array of applications involving both traditional and computational imaging systems. Areas of potential benefits are discussed, and three applications are presented, demonstrating the utility of the phase of the complex frequency response in practical scenarios. In traditional imaging systems, the PTF is shown via simulation results to be strongly coupled with odd-order aberrations and hence useful in misalignment detection and correction. In computational imaging systems, experimental results confirm that the PTF can be successfully applied to subpixel shift estimation and wavefront coding characterization tasks.

Experimental evidence of the theoretical spatial frequency response of cubic phase mask wavefront coding imaging systems.

The optical transfer function of a cubic phase mask wavefront coding imaging system is experimentally measured across the entire range of defocus values encompassing the system's functional limits. The results are compared against mathematical expressions describing the spatial frequency response of these computational imagers. Experimental data shows that the observed modulation and phase transfer functions, available spatial frequency bandwidth and design range of this imaging system strongly agree with previously published mathematical analyses. An imaging system characterization application is also presented wherein it is shown that the phase transfer function is more robust than the modulation transfer function in estimating the strength of the cubic phase mask.

Effects of sampling on the phase transfer function of incoherent imaging systems.

With the advent of modern-day computational imagers, the phase of the optical transfer function may no longer be summarily ignored. This study discusses some important properties of the phase transfer function (PTF) of digital incoherent imaging systems and their implications on the performance and characterization of these systems. The effects of aliasing and sub-pixel image shifts on the phase of the complex frequency response of these sampled systems are described, including an examination of the specific case of moderate aliasing. Key properties of this function in aliased imaging systems are derived and their potential treatment to a range of diverse applications encompassing traditional and computational imaging systems is discussed.

Experimentally validated computational imaging with adaptive multiaperture folded architecture.

We present experimental results of imaging and digital superresolution in a multiaperture miniature folded imaging architecture called PANOPTES. We prove the feasibility of integrating a low f-number folded imagers within a steerable multiaperture framework while maintaining a thin profile. Stringent requirements including low f-number and compact form factor, combined with the need for an ability to steer individual fields of view necessitate an off-axis design, resulting in a plane symmetric optical system. We present a detailed description of the ensuing optical design and its performance. The feasibility of this architecture is demonstrated through experiments and preliminary reconstruction results.