Estimating temperatures with low-cost infrared cameras using physically-constrained deep neural networks.

Low-cost thermal cameras are inaccurate (usually ±3 ) and have space-variant nonuniformity across their detectors. Both inaccuracy and nonuniformity are dependent on the ambient temperature of the camera. The goal of this work was to estimate temperatures with low-cost infrared cameras, and rectify the nonuniformity.

Simultaneous Temperature Estimation and Nonuniformity Correction From Multiple Frames.

IR cameras are widely used for temperature measurements in various applications, including agriculture, medicine, and security. Low-cost IR cameras have the immense potential to replace expensive radiometric cameras in these applications; however, low-cost microbolometer-based IR cameras are prone to spatially variant nonuniformity and to drift in temperature measurements, which limit their usability in practical scenarios. To address these limitations, we propose a novel approach for simultaneous temperature estimation and nonuniformity correction (NUC) from multiple frames captured by low-cost microbolometer-based IR cameras.

Temporal Super-Resolution Using a Multi-Channel Illumination Source.

While sensing in high temporal resolution is necessary for a wide range of applications, it is still limited nowadays due to the camera sampling rate. In this work, we try to increase the temporal resolution beyond the Nyquist frequency, which is limited by the sensor's sampling rate. This work establishes a novel approach to temporal super-resolution that uses the object-reflecting properties from an active illumination source to go beyond this limit.

Illumination-Based Color Reconstruction for the Dynamic Vision Sensor.

This work demonstrates a novel, state-of-the-art method to reconstruct colored images via the dynamic vision sensor (DVS). The DVS is an image sensor that indicates only a binary change in brightness, with no information about the captured wavelength (color) or intensity level. However, the reconstruction of the scene's color could be essential for many tasks in computer vision and DVS.

Hardware analysis for motion estimation task.

This work introduces hardware metrics to evaluate imaging sensor (camera) ability to cope with temporal change (motion). Shifting from images towards moving elements demands better tools for evaluation than just refresh rate, and this work is here to close that gap. We focus on the sampling frequency, signal to noise ratio, rolling shutter, and modulation transfer function as a set of parameters to define four fundamental conditions to evaluate and compare the quality of motion sensing.

Pentagraph image fusion scheme for motion blur prevention using multiple monochromatic images.

This paper introduces the pentagraph image fusion (PIF) scheme for motion-related blur prevention in images. The PIF algorithm processes five monochromatic images into a single, low-noise, no-blur color image. The images are acquired using a new photography scheme, sequential filter photography (SFP), where instead of using a stationary Bayer pattern color filter array in front of the image sensor, a tunable color filter array is used.

Sequential filtering for color image acquisition.

We present an alternative method of color imaging. It utilizes a single standard Si-based image sensor and a clear aperture, tunable, color filter. Within this scheme, three monochromatic frames are taken; each is acquired with a single color and with a fraction of the total acquisition duration.

Blurred and noisy image pairs in parallel optics.

In previous works we have shown that parallel optics (PO) architecture can be used to improve the system matrix condition, which results in improving its immunity to additive noise in the image restoration process. PO is composed of a "main" system and an "auxiliary" system. Previously, we suggested the "trajectories" method to realize PO.

Design of an image restoration algorithm for the TOMBO imaging system.

The TOMBO system (thin observation module by bound optics) is a multichannel subimaging system over a single electronic imaging device. Each subsystem provides a low-resolution (LR) image from a unique lateral point of view. By estimating the image's lateral position, a high-resolution (HR) image is restored from the series of the LR images.

Toward a super imaging system [Invited].

This paper deals with the fast-developing area of computational photography where a combination of imaging techniques and efficient image processing algorithms is done to generate a super imaging system. In recent years, three main implementations of the computational photography philosophy were intensively investigated and demonstrated: (i) multiple aperture, (ii) light field photography, and (iii) multiexposure. The paper provides a mini-review of these three approaches and shows ways to improve and combine them toward a super imaging system.

Experimental results for improving the matrix condition using a hybrid optical system.

We present preliminary experimental results for implementing the "blurred trajectories" method on three parallel optics (PO) systems. The "main" system and "auxiliary" optics were simple laboratory graded lenses attached to an iris diaphragm. When applying the blurred trajectories method we first show an improvement in the matrix condition, as the matrix condition number decreased in a range of factors of 3 to 418 relative to the main system.

Trajectories in parallel optics.

In our previous work we showed the ability to improve the optical system's matrix condition by optical design, thereby improving its robustness to noise. It was shown that by using singular value decomposition, a target point-spread function (PSF) matrix can be defined for an auxiliary optical system, which works parallel to the original system to achieve such an improvement. In this paper, after briefly introducing the all optics implementation of the auxiliary system, we show a method to decompose the target PSF matrix.

Improvement of matrix condition of Hybrid, space variant optics by the means of parallel optics design.

The problem of image restoration of space variant blur is common and important. One of the most useful descriptions of this problem is in its algebraic form I=H*O, where O is the object represented as a column vector, I is the blur image represented as a column vector and H is the PSF matrix that represents the optical system. When inverting the problem to restore the geometric object from the blurred image and the known system matrix, restoration is limited in speed and quality by the system condition.

Experimental measurement of quality factor enhancement using slow light modes in one dimensional photonic crystal.

We experimentally investigate the effects of slow light modes within a one dimensional photonic crystal resonator. We show that the slow light mode leads to significant increase in the quality factor of the resonator. We provide a theoretical analysis explaining our experimental results.

Highly dispersive micro-ring resonator based on one dimensional photonic crystal waveguide design and analysis.

We propose and analyze a novel design of a hybrid micro-ring resonator and photonic crystal device. The proposed device is based on a micro-ring resonator with the addition of a series of periodic defects that are introduced to the microring. When the wavelength of operation approaches the band-gap of the periodic structure, the modal dispersion is significantly increased.

Passive and periodically ultra fast RF-photonic spectral scanner.

In this paper we present passive photonic device performing periodic and ultra fast spectral analysis of RF signals modulated on optical carrier. The spectral scanning is demonstrated in two approaches. First by passing the light through a couple of special bulk periscopes that split the beam into a set of parallel channels or combine a set of channels into one beam.

Fuzzy-logic optical optimization of mainframe CPU and memory.

The allocation of CPU time and memory resources is a familiar problem in organizations with a large number of users and a single mainframe. Usually the amount of resources allocated to a single user is based on the user's own statistics not on the statistics of the entire organization, therefore patterns are not well identified and the allocation system is prodigal. A fuzzy-logic-based algorithm to optimize the CPU and memory distribution among users based on their history is suggested.

Radio frequency photonic filter for highly resolved and ultrafast information extraction.

We present a method and devices for highly resolved carrier and information extraction of optically modulated radar signals. The extraction is done by passing the optical beam through a monitoring path that constitutes a finite impulse response filter. Replications of the monitoring signal realize the required spectral scan of the filter.

Analysis of waveguide-splitter-junction in high-index Silicon-On-Insulator waveguides.

We propose and analyze a new type of four ports structure for ultra-compact waveguide splitting. This structure differs from most existing ultra-compact waveguide splitters by introducing complete symmetry between the input and output ports. Maximum overall throughput predicted is ~81% where reflection and crosstalk are <1%.

Geometric superresolution by code division multiplexing.

In many highly resolved optical systems the resolution is limited not by the optics but by the CCD's nonzero pixel size. As a result, overall resolution is decreased. Here we propose a novel approach to enhancing resolution beyond the limit set by the CCD's pixels.

Realization of temporal linear transformations by the use of a spatial-diffraction-based optical system.

Signal processing in general, and optical signal processing in particular, make extensive use of linear transformations. The temporal nature of many optical signals (e.g.

Optical characteristics of the compound PLZT.

We present a summary of measured characteristics of lanthanum-doped lead zirconium titanate (PLZT) compound in its mechanical housing. It is expected that the PLZT device will be used as the main component in an ultrafast electro-optic switch. We have performed several experiments to measure and calculate the following characteristics: optical power transmission, thermodynamic effects, switching speed, and dc drift phenomenon.

Invariant pattern recognition by use of a spatial code division multiplexing approach.

Invariant pattern recognition can be achieved by use of harmonic decomposition, for example circular harmonics are used for rotation invariant recognition. A common problem with such methods is that often only a single term of the harmonic decomposition is used, and it does not contain a sufficient amount of the reference energy. Thus discrimination capability is limited, especially in the presence of noise or other disturbances.

Optical transfer function shaping and depth of focus by using a phase only filter.

The design of a desired optical transfer function (OTF) is a common problem that has many possible applications. A well-known application for OTF design is beam shaping for incoherent illumination. However, other applications such as optical signal processing can also be addressed with this system.

Superresolution by use of code division multiplexing.

Traditional methods for superresolution have sacrificed field of view for resolution. These methods multiplexed different parts of signals' spectrum on different carriers, and thus managed to transfer a wider range of frequency, in a manner that is similar to frequency division multiplexing in classical communication. We propose code division multiplexing for such an application, which has been shown to have superior capabilities.