Prototype development and field-test results of an adaptive multiresolution PANOPTES imaging architecture.

The design, development, and field-test results of a visible-band, folded, multiresolution, adaptive computational imaging system based on the Processing Arrays of Nyquist-limited Observations to Produce a Thin Electro-optic Sensor (PANOPTES) concept is presented. The architectural layout that enables this imager to be adaptive is described, and the control system that ensures reliable field-of-view steering for precision and accuracy in subpixel target registration is explained. A digital superresolution algorithm introduced to obtain high-resolution imagery from field tests conducted in both nighttime and daytime imaging conditions is discussed.

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.

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.

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.

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.

Improving photon count and flat profiles of multiplex imaging systems with the odd-symmetric quadratic phase modulation mask.

The odd-symmetric quadratic (OSQ) phase mask is examined as a candidate for reduction of working distance and enhancement of light collection in multiplex imaging systems. The knowledge gained from the exact mathematical representation of the optical transfer function of the OSQ phase mask imager is exploited to explain the limits of system performance and quantify the upper bound on the magnitude of defocus within which this wavefront coding imager can successfully operate. The sensitivity of this imaging system to defocus about the special imaging condition that yields an enhanced dynamic range is examined, and it is shown that the modulation transfer function (MTF) degradation when the magnitude of misfocus is increased past this condition is much more gradual than the degradation of a conventional imager past a zero-misfocus state.

Frequency analysis of the wavefront-coding odd-symmetric quadratic phase mask.

A mathematical analysis of the frequency response of the wavefront-coding odd-symmetric quadratic phase mask is presented. An exact solution for the optical transfer function of a wavefront-coding imager using this type of mask is derived from first principles, whose result applies over all misfocus values. The misfocus-dependent spatial filtering property of this imager is described.

Enhancing form factor and light collection of multiplex imaging systems by using a cubic phase mask.

The bulky form factor of traditional optical sensors limits their utility for certain applications. Flat multiplex imaging-sensor architectures face the light-gathering challenges inherent with small collection apertures. We examine a wavefront-coding approach wherein a cubic phase mask is used to increase the aperture sizes of multiplex imaging systems while maintaining the distance from the lens to the detector array.