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HEVC extension for phase hologram compression

OPTICS EXPRESS 2023年第6期31卷 9146-9164页

作者： Oh, Kwan-jung Ban, Hyunmin Choi, Seungmi Ko, Hyunsuk Kim, Hui Yong Elect & Telecommun Res Inst ETRI Media Res Div 218 Gajeong Ro Daejeon South Korea Kyung Hee Univ Sch Comp 1732 Deogyeong Daero Yongin Gyeonggi Do South Korea Hanyang Univ ERICA Sch Elect Engn 55 Hanyangdeahak Ro Ansan Gyeonggi Do South Korea

Compressing digital holograms have growing attention nowadays due to their huge amount of original data sizes. Although many progresses have been reported for full-complex holograms, the coding performance for phase-only holograms (POHs) has been quite limited so far. In this paper, we present a very efficient compression method for POHs. It extends the conventional video coding standard HEVC (High Efficiency Video Coding) in such a way that the standard can be able to compress not only the natural images but also the phase images effectively. First, we suggest a proper way to calculate differences, distances and clipped values for phase signals by considering the inherent periodicity of phases. Then, some of the HEVC encoding and decoding processes are modified accordingly. The experimental results show that the proposed extension significantly outperforms the original HEVC for POH video sequences;specifically, average BD-rate reductions of 63.3% and 65.5% are achieved in phase domain and numerical reconstruction domain, respectively. It is worth mentioning that the modified encoding & decoding processes are very minimal and also applicable to the VVC (Versatile Video Coding), which is a successor of the HEVC.(c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

关键词： Digital holographic imaging image processing algorithms image quality Phase unwrapping Three dimensional imaging Wavelet transforms

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BOUNDARY DETECTION IN MULTIDIMENSIONS

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IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE 1982年第1期4卷 41-50页

作者： UDUPA, JK SRIHARI, SN HERMAN, GT SUNY BUFFALO DEPT COMP SCIBUFFALONY 14226

The development of image processing algorithms for time-varying imagery and computerized tomography data calls for generalization of the concepts of adjacency, connectivity, boundary, etc., to three and four-dimensional discrete spaces. This paper defines these basic concepts in unified terminology and presents algorithms for a boundary detection task in multidimensional space. The performance of these algorithms is discussed with respect to theoretical maximum complexity, and is illustrated with simulated computerized tomography data.

关键词： Multidimensional systems Computed tomography image reconstruction Three dimensional displays image processing Two dimensional displays Computer displays Biomedical image processing Computer science Terminology Author Keywords time-varying imagery Adjacency and connectivity in multidimensions boundary detection computerized tomography image processing algorithms

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Automated bone cell classification for confocal laser scanning microscopy volumes

OPTICS CONTINUUM

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OPTICS CONTINUUM 2022年第6期1卷 1364-1374页

作者： Flannery, Brennan T. Xu, Xiaoyu Golz, Brian T. Main, Russell P. Case Western Reserve Univ Dept Biomed Engn 10900 Euclid Ave Cleveland OH 44106 USA Purdue Univ Weldon Sch Biomed Engn 206 South Martin Jischke Dr W Lafayette IN 47907 USA Purdue Univ Dept Basic Med Sci 625 Harrison St W Lafayette IN 47907 USA

Manual cell classification in microscopy images is a time-consuming process that heavily relies on the subjective perception of the investigator. Identifying bone cells introduces additional difficulties with irregular geometries, and in some culture conditions, the presence of bone mineral. As fluorescence-based lineage tracing becomes more common, classifying cell types based upon cell color can further increase subjectivity. Our goal is to develop and validate a fully automated cell classification algorithm that can (i) objectively identify cells in flattened volumetric image stacks from three-dimensional (3D) bone cell cultures and (ii) classify the cells (osteoblast-lineage) based on the color of their cell bodies. The algorithm used here was developed in MATLAB 2019a and validated by comparing code outputs to manual labeling for eleven images. The precision, recall, and F1 scores were higher than 0.75 for all cell classifications, with the majority being greater than 0.80. No significant differences were found between the manually labelled and automated cell counts or cell classifications. Analysis time for a single image averaged seventeen seconds compared to more than ten minutes for manual labeling. This demonstrates that the program offers a fast, repeatable, and accurate way to classify bone cells by fluorescence in confocal microscopy image data sets. This process can be expanded to improve investigation of other pre-clinical models and histological sections of pathological tissues where color or fluorescence-based differences are used for cell identification.

关键词： Fluorescent markers image analysis image processing image processing algorithms image stacking Multiple imaging

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Automated Analysis of Lesion Depth and Integrated Reflectivity in PS-OCT Scans of Tooth Demineralization

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LASERS IN SURGERY AND MEDICINE 2010年第1期42卷 62-68页

作者： Le, Michael H. Darling, Cynthia L. Fried, Daniel Univ Calif San Francisco Dept Prevent & Restorat Dent Sci San Francisco CA 94143 USA

Background and Objectives: Several studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to nondestructively measure the severity of subsurface demineralization in enamel and dentin, track lesion progression over time and measure remineralization. The purpose of this study was to develop methods for the automated assessment of the depth and severity of demineralization in PS-OCT scans. Materials and Methods: Subsurface caries-like lesions of increasing depth and severity were produced in adjoining windows on 10 bovine enamel samples via exposure to demineralization for periods of 1-4 days. PS-OCT scans were acquired for each sample and analyzed using various methods to calculate the lesion depth and severity. Edge detection algorithms were most successful for measurement of the lesion depth for improved assessment of lesion severity. Results: Edge-finding algorithms were able to detect significant differences (P < 0.05) in the lesion depth and severity between each of the periods of demineralization and sound enamel. The lesion depth and mineral loss were also measured with polarized light microscopy and transverse microradiography after sectioning the teeth for comparison. Conclusions: This study demonstrates that the depth and severity of early lesions can be calculated automatically for rapid analysis of PS-OCT images. Lasers Surg. Med. 42:62-68, 2010. (C) 2010 Wiley-Liss, Inc.

关键词： enamel caries PS-OCT image processing algorithms early demineralization edge detection

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Periodic poling with a micrometer-range period in thin-film lithium niobate on insulator

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JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 2021年第3期38卷 685-691页

作者： Younesi, Mohammadreza Geiss, Reinhard Rajaee, Shakiba Setzpfandt, Frank Chen, Yen-Hung Pertsch, Thomas Friedrich Schiller Univ Jena Abbe Ctr Photon Inst Appl Phys Albert Einstein Str 15 D-07745 Jena Germany Ernst Abbe Hsch Jena Carl Zeiss Promenade 2 D-07745 Jena Germany Natl Cent Univ Dept Opt & Photon Jhongli 320 Taiwan Natl Cent Univ Ctr Astronaut Phys & Engn Jhongli 320 Taiwan Fraunhofer Inst Appl Opt & Precis Engn IOF Ctr Excellence Photon Albert Einstein Str 7 D-07745 Jena Germany

We present our experimental results on electric field poling of X-cut thin-film lithium niobate with poling periods of 1-4 mu m. We used polarization contrast microscopy combined with digital image processing to study the impact of the experimental parameters of the poling process such as electric field strength, poling pulse duration, and layout of metal electrodes on the domain growth and quality of resulting poling patterns. High-quality results with excellent homogeneity of the domain pattern on large areas [i.e., 16 mu m along the domain (z axis) and millimeter long domain gratings along the y axis with a period down to 1 mu m] allow for the integration of numerous devices and structures. (C) 2021 Optical Society of America

关键词： Digital image processing Electron beam lithography image processing algorithms Lithium niobate Phase matching Refractive index

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PHASE PROBLEM IN CRYSTALLOGRAPHY

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JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS image SCIENCE AND VISION 1993年第5期10卷 1046-1055页

作者： HARRISON, RW Department of Pharmacology Bluemle Life Sciences Building Thomas Jefferson University233 South 10th Street Philadelphia Pennsylvania 19107 USA

Phase recovery from unphased data is the central problem in the interpretation of crystal diffraction data. There are a number of experimental methods for determining phases, and for small molecules computational methods work very well. The problem of developing robust computational methods for large molecules is not yet solved. Most of the approaches for large molecules are variants of the Grechburg-Saxton algorithm [Optik 35, 237-246 (1972)];with sufficiently good initial phase estimates these converge, but in general they fail with phase stagnation similar to that seen in image processing [J. C. Dainty and J. R. Fienup, in image Recovery: Theory and Application, H. Stark, ed. (Academic, Orlando, Fla., 1987);J. R. Fienup and C. C. Wackerman, J. Opt. Soc. Am. A 3, 1897-1907 (1986)].

关键词： Computation methods Discrete Fourier transforms Fast Fourier transforms image processing image processing algorithms Phase recovery

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Features of the calculation of the range of action of a television device in the nocturnal regime

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JOURNAL OF OPTICAL TECHNOLOGY 2004年第10期71卷 699-701页

作者： Grinkevich, AV ZAO EVS St Petersburg Russia

关键词： Attenuation Brightness Charge coupled devices Illuminance image metrics image processing algorithms

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Toward a UV-visible-near-infrared hyperspectral imaging platform for fast multiplex reflection spectroscopy

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OPTICS LETTERS 2010年第20期35卷 3330-3332页

作者： Li, Jianping Chan, Robert K. Y. Hong Kong Baptist Univ Dept Phys Hong Kong Hong Kong Peoples R China

A reflection hyperspectral imaging system covering a 350-1000 nm spectral range is realized by a UV-visible-nearIR Fourier transform imaging spectrometer. The system has a simple design and good spectral and spatial resolving performance. Accurate and fast microspectroscopic measurement results on novel colloidal crystal beads demonstrate the system has practical potential for high-throughput molecular multiplex assays. (C) 2010 Optical Society of America

关键词： Hyperspectral imaging image processing image processing algorithms image resolution Optical testing Spectroscopy

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Athermalization of dual-waveband infrared systems containing diffractive optical elements via optical-digital joint design

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APPLIED OPTICS 2020年第4期59卷 1212-1216页

作者： Hu, Yang Cui, Qingfeng Sun, Lin Zhang, Bo Changchun Univ Sci & Technol Sch Optoelect Engn Changchun 130022 Peoples R China

Because of material limitations, achieving an athermal design for dual-waveband infrared systems is difficult. This study integrates single-layer diffractive elements to reduce the volume and weight of such a design and introduces optical-digital joint methods to eliminate the impact of low diffraction efficiency. To achieve athermalization, temperature polychromatic integral diffraction efficiency and temperature integral wavelength weight are incorporated in the point spread function (PSF) model. Influence of low diffraction efficiency is eliminated via subsequent algorithm processing. Accordingly, athermal design and processing of a cooled dual-waveband infrared system is achieved and verified via experimental results. (C) 2020 Optical Society of America

关键词： Diffraction efficiency Diffractive optical elements image processing image processing algorithms image quality Infrared systems

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Compact, broad-bandwidth fiber laser for sub-2-μm axial resolution optical coherence tomography in the 1300-nm wavelength region

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OPTICS LETTERS 2003年第9期28卷 707-709页

作者： Bizheva, K Povazay, B Hermann, B Sattmann, H Drexler, W Mei, M Holzwarth, R Hoelzenbein, T Wacheck, V Pehamberger, H Univ Vienna Christian Doppler Lab Dept Phys Med Vienna Austria MenloSyst GMBH D-82152 Martinsried Germany Univ Vienna Dept Vasc Surg Gen Hosp Vienna Vienna Austria Univ Vienna Dept Clin Pharmacol Gen Hosp Vienna Vienna Austria Univ Vienna Dept Dermatol Gen Hosp Vienna Vienna Austria

A novel, compact, user friendly fiber laser with a broad emission bandwidth (MenloSystems, lambda(c) = 1375 am, Deltalambda = 470 nm, P-out = 4 mW) was used to achieve unprecedented sub-2-mum axial resolution optical coherence tomography (OCT) in nontransparent biological tissue in the 1300-nm wavelength region. Fresh human skin and arterial biopsies were imaged ex vivo with similar to1.4-mum axial and similar to3-mum lateral resolution and 95-dB sensitivity, demonstrating the great potential for clinical OCT applications of this stable, low-cost, and turn-on-key fiber laser. (C) 2003 Optical Society of America.

关键词： Fiber lasers image processing algorithms Light sources Optical coherence tomography Optical imaging Pulsed fiber lasers

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