A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry

Current medical imaging technologies allow visualization of tissue anatomy in the human body at resolutions ranging from 100 micrometers to 1 millimeter. These technologies are generally not sensitive enough to detect early-stage tissue abnormalities associated with diseases such as cancer and atherosclerosis, which require micrometer-scale resolution. Here, optical coherence tomography was adapted to allow high-speed visualization of tissue in a living animal with a catheter-endoscope 1 millimeter in diameter. This method, referred to as "optical biopsy," was used to obtain cross-sectional images of the rabbit gastrointestinal and respiratory tracts at 10-micrometer resolution.

In Vivo Endoscopic Optical Biopsy with Optical Coherence Tomography

Systems and methods for implementing array cameras configured to perform super- resolution processing to generate higher resolution super-resolved images using a plurality of captured images and lens stack arrays that can be utilized in array cameras are disclosed. Lens stack arrays in accordance with many embodiments of the invention include lens elements formed on substrates separated by spacers, where the lens elements, substrates and spacers are configured to form a plurality of optical channels, at least one aperture located within each optical channel, at least one spectral filter located within each optical channel, where each spectral filter is configured to pass a specific spectral band of light, and light blocking materials located within the lens stack array to optically isolate the optical channels.

Capturing and processing of images using monolithic camera array with heterogeneous imagers

An image processing apparatus and image processing method capable of providing a high-resolution image for a desired position by use of light field data are provided. The image processing apparatus may determine a position of a portion of light field data among light field data corresponding to a scene, according to a desired focusing position, generate a refocusing first image by use of the position determined portion of light field data, generate a high-resolution image having a predetermined setting ratio relative to the refocusing first image, determine a ratio for local synthesis between the high-resolution image and an enlarged image of the refocusing first image by use of a similarity with respect to the position determined portion of light field data, and generate a synthesized image by synthesizing the high-resolution image and the enlarged image of the refocusing first image according to the local synthesis ratio.

Image processing apparatus and method

There are many, many inventions described herein. In one aspect, what is disclosed is a digital camera including a plurality of arrays of photo detectors, including a first array of photo detectors to sample an intensity of light of a first wavelength and a second array of photo detectors to sample an intensity of light of a second wavelength. The digital camera further may also include a first lens disposed in an optical path of the first array of photo detectors, wherein the first lens includes a predetermined optical response to the light of the first wavelength, and a second lens disposed in with an optical path of the second array of photo detectors wherein the second lens includes a predetermined optical response to the light of the second wavelength. In addition, the digital camera may include signal processing circuitry, coupled to the first and second arrays of photo detectors, to generate a composite image using (i) data which is representative of the intensity of light sampled by the first array of photo detectors, and (ii) data which is representative of the intensity of light sampled by the second array of photo detectors; wherein the first array of photo detectors, the second array of photo detectors, and the signal processing circuitry are integrated on or in the same semiconductor substrate.

Apparatus for multiple camera devices and method of operating same

To improve the reconstructed image quality in a 3D display system using binary phase modulator, we propose two successive methods that are a modified iterative Fresnel algorithm for designing the binary phase pattern and the intensity addition for the speckle reduction. Numerical and experimental results show the effectiveness of the proposed methods by increasing the number of iteration for optimizing the binary phase distribution and the number of intensity addition.

Improvement of Image Quality of 3D Display by Using Optimized Binary Phase Modulation and Intensity Accumulation

We evaluate numerically the effect of shrinkage of photopolymer on the bit error rate or signal-to-noise ratio in a reflection-type holographic data storage system with angular multiplexing. In the evaluation, we use a simple model where the material is divided into layered structures and then the shrinkage rate is proportional to the intensity in each layer. We present the effectiveness of the proposed model from the experimental results in the recording of the plane waves both in a transmission-type hologram and a reflection-type one. Several kinds of shrinkage rates are used to evaluate the characteristics of angular multiplexing in the reflection-type holographic memory.

Numerical evaluation of angular multiplexing in reflection-type holographic data storage in photopolymer with shrinkage

A volume scattering medium was fabricated in a transparent material by focused femtosecond laser pulses. A random distribution of voids fabricated by femotosecond pulsed laser light acted as a volume scattering medium that may be applied to photonic secure data storage. We fabricated a partially random distribution of voids in poly(methyl methacrylate) and then measured the scattering properties. Comparing beam widths of the output intensity distribution through the scattering medium, obtained from both complex amplitude propagation and Monte Carlo simulation, showed that the scattering coefficient can be controlled by the void density.

Fabrication of controlled volume scattering medium in poly(methyl methacrylate) by focused femtosecond laser pulses

Minimum optical energy required for four-step parallel phase-shifting digital holography (PPSDH) is evaluated numerically by using photon-counting analysis. PPSDH enables us to develop instantaneous three-dimensional (3D) measurement by single-shot measurement. In fast measurement of dynamic 3D events, detected optical power at an image sensor will be decreased. For biomedical sensing, maximum light intensity exists for preventing the damage of the tissue. In the numerical evaluation, a photon-counting approach is used for the evaluation of minimum detected energy by comparing the reconstructed images. Numerical results indicate that hundreds of photons at each pixel in the image sensor are enough for the reconstruction and total detected energy in a multiplexed hologram is about 1 pJ.

Assessment of weak light condition in parallel four-step phase-shifting digital holography

We propose a numerical method to obtain complex amplitude distribution of a three-dimensional (3D) object from a digital hologram. The method consists of two processes. The first process is to measure simultaneously a hologram of the 3D object and an object intensity distribution by two image sensors. These intensity distributions give us the amplitude and absolute value of phase of the 3D object at the image sensor plane. The second process is the determination of phase distribution by a proposed iterative process based on the criterion that the reconstructed 3D object is in focus and its conjugate reconstruction is out of focus. Numerical and experimental results show the effectiveness of the proposed method.

Kouichi Nitta

Papers

Improvement of Image Quality of 3D Display by Using Optimized Binary Phase Modulation and Intensity Accumulation

Numerical evaluation of angular multiplexing in reflection-type holographic data storage in photopolymer with shrinkage

Fabrication of controlled volume scattering medium in poly(methyl methacrylate) by focused femtosecond laser pulses

Assessment of weak light condition in parallel four-step phase-shifting digital holography

Iterative algorithm of phase determination in digital holography for real-time recording of real objects