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Author

Kouichi Nitta

Bio: Kouichi Nitta is an academic researcher from Kobe University. The author has contributed to research in topics: Holography & Digital holography. The author has an hindex of 15, co-authored 92 publications receiving 919 citations.


Papers
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Journal ArticleDOI
TL;DR: This work investigates a novel procedure combining a pixel-rearrangement method and iterative backprojection (IBP) for reconstructing high-spatial-resolution images in an imaging system known as thin observation module by bound optics.
Abstract: A method for reconstructing high-spatial-resolution images in an imaging system known as thin observation module by bound optics (TOMBO) is reported. We investigate a novel procedure combining a pixel-rearrangement method and iterative backprojection (IBP). Pixel rearrangement has been used until now in TOMBO, and IBP is a digital superresolution technique. We verify the effectiveness of the combined procedure with simulated and experimental results.

170 citations

Patent
01 Dec 2004
TL;DR: Using image data on a plurality of reduced object images to calculate a shift amount in regard to the gap of relative positions between the reduced object image by a correlation calculation between the images, a conversion equation is obtained from the shift amount for geometric projection process from the object image to each of the images as discussed by the authors.
Abstract: Using image data on a plurality of reduced object images to calculate a shift amount in regard to the gap of relative positions between the reduced object images by a correlation calculation between the reduced object images. A conversion equation is obtained from the shift amount for geometric projection process from the object image to each of the reduced object images. Initial image data on a single object image is generated using image data on the plurality of reduced object images. This and the aforementioned conversion equation, are used to estimate images of each of the reduced object images. A difference between the estimated image of each of the reduced object images and each of the reduced object images is projected in the reverse process of the aforementioned geometric projection process, to update the image data on the single object image. The processes are repeated until the difference satisfies a predetermined condition and a high resolution object image is outputted.

109 citations

Proceedings ArticleDOI
17 Oct 2006
TL;DR: The Transmissive Mirror Device (TMD) as discussed by the authors is a micro-mirror array, which consists of numerous micromirrors placed perpendicular to the surface of a flat, thin metal plate.
Abstract: We propose a new imaging optics called the Transmissive Mirror Device (TMD). It consists of numerous micromirrors placed perpendicular to the surface of a flat, thin metal plate. The micro-mirror array is implemented by the inner walls of minute square holes, which are densely pitted on the device. The basic mode of operation is based on two reflections by a pair of adjacent mutually perpendicular mirrors, i.e., a dihedral corner reflector. Although the principal of operation is based on reflection by mirrors, the device is also transmissive and deflects light. Since this imaging system forms a real image at a plane symmetric point, the depth of the 3D image is inverted. Its optical defects are low optical transmittance and stray light caused by non-reflected light and that reflected once. We manufactured the device experimentally with nano-precision machining technology and also evaluated it.

105 citations

Journal ArticleDOI
TL;DR: The phase-mode SLM implements spatial distribution of phase retardation required in the parallel phase-shifting digital holography and can also compensate dynamically the phase distortion caused by optical elements such as beam splitters, lenses, and air fluctuation.
Abstract: Parallel phase-shifting digital holography using a phase-mode spatial light modulator (SLM) is proposed. The phase-mode SLM implements spatial distribution of phase retardation required in the parallel phase-shifting digital holography. This SLM can also compensate dynamically the phase distortion caused by optical elements such as beam splitters, lenses, and air fluctuation. Experimental demonstration using a static object is presented.

65 citations

Journal ArticleDOI
TL;DR: A system that combines fluorescence microscopy and digital holographic microscopy into a single system for biological applications and the measurement of fluorescence beads and egera densa presented the feasibility of simultaneous detection of both a phase image and a fluorescence image.
Abstract: Hybrid digital holographic microscopy that combines fluorescence microscopy and digital holographic microscopy into a single system for biological applications is proposed. In the proposed system, a phase image and a fluorescence image can be obtained simultaneously by selecting the different wavelengths of the fluorescent light and the phase measurement. Especially for biological applications, the cell structure can be obtained by the phase imaging based on digital holography and nucleus of the cell can be obtained by the fluorescence imaging. The measurement of fluorescence beads and egera densa presented the feasibility of simultaneous detection of both a phase image and a fluorescence image.

56 citations


Cited by
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Journal Article
TL;DR: In this article, a fast Fourier transform method of topography and interferometry is proposed to discriminate between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour generation techniques.
Abstract: 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.

3,742 citations

Journal Article
TL;DR: In this article, optical coherence tomography was adapted to allow high-speed visualization of tissue in a living animal with a catheter-endoscope 1 millimeter in diameter, which was used to obtain cross-sectional images of the rabbit gastrointestinal and respiratory tracts at 10-micrometer resolution.
Abstract: 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.

1,285 citations

Patent
20 May 2009
TL;DR: In this paper, the system 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.
Abstract: 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.

594 citations

Patent
Jae-guyn Lim1, Hyun-wook Ok, Byung-kwan Park, Seong-deok Lee, Joo-young Kang 
14 Apr 2010
TL;DR: In this paper, 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, where the image processing equipment may determine a position of a portion of light-field data among light- field data corresponding to a scene, generate a refocusing first image by using of the position determined portion of LFD data, determine a high resolution image having a predetermined setting ratio relative to the first image, and generate a synthesized image by synthesizing the highresolution image and the enlarged image of the re-focus first
Abstract: 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.

478 citations

Patent
25 Aug 2005
TL;DR: In this paper, a digital camera including a plurality of arrays of photo detectors, including a first array of photo detector to sample an intensity of light of a first wavelength and a second array of camera sensor to sample a second wavelength, is described.
Abstract: 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.

334 citations