The First Public Release of South Pole Telescope Data: Maps of a 95 deg^2 Field from 2008 Observations

The South Pole Telescope (SPT) has nearly completed a 2500 deg^2 survey of the southern sky in three frequency bands. Here, we present the first public release of SPT maps and associated data products. We present arcminute-resolution maps at 150 GHz and 220 GHz of an approximately 95 deg^2 field centered at R.A. 82°.7, decl. –55°. The field was observed to a depth of approximately 17 μK arcmin at 150 GHz and 41 μK arcmin at 220 GHz during the 2008 austral winter season. Two variations on map filtering and map projection are presented, one tailored for producing catalogs of galaxy clusters detected through their Sunyaev-Zel'dovich effect signature and one tailored for producing catalogs of emissive sources. We describe the data processing pipeline, and we present instrument response functions, filter transfer functions, and map noise properties. All data products described in this paper are available for download at http://pole.uchicago.edu/public/data/maps/ra5h30dec-55 and from the NASA Legacy Archive for Microwave Background Data Analysis server. This is the first step in the eventual release of data from the full 2500 deg^2 SPT survey

The curvelet transform for image denoising

We describe approximate digital implementations of two new mathematical transforms, namely, the ridgelet transform and the curvelet transform. Our implementations offer exact reconstruction, stability against perturbations, ease of implementation, and low computational complexity. A central tool is Fourier-domain computation of an approximate digital Radon transform. We introduce a very simple interpolation in the Fourier space which takes Cartesian samples and yields samples on a rectopolar grid, which is a pseudo-polar sampling set based on a concentric squares geometry. Despite the crudeness of our interpolation, the visual performance is surprisingly good. Our ridgelet transform applies to the Radon transform a special overcomplete wavelet pyramid whose wavelets have compact support in the frequency domain. Our curvelet transform uses our ridgelet transform as a component step, and implements curvelet subbands using a filter bank of a` trous wavelet filters. Our philosophy throughout is that transforms should be overcomplete, rather than critically sampled. We apply these digital transforms to the denoising of some standard images embedded in white noise. In the tests reported here, simple thresholding of the curvelet coefficients is very competitive with "state of the art" techniques based on wavelets, including thresholding of decimated or undecimated wavelet transforms and also including tree-based Bayesian posterior mean methods. Moreover, the curvelet reconstructions exhibit higher perceptual quality than wavelet-based reconstructions, offering visually sharper images and, in particular, higher quality recovery of edges and of faint linear and curvilinear features. Existing theory for curvelet and ridgelet transforms suggests that these new approaches can outperform wavelet methods in certain image reconstruction problems. The empirical results reported here are in encouraging agreement

Man-machine interactive imaging and data processing using high-speed digital mass storage

The role of vision in teleoperation has been recognized as an important element in the man-machine control loop. In most applications of remote manipulation, direct vision cannot be used. To overcome this handicap, the human operator's control capabilities are augmented by a television system. This medium provides a practical and useful link between workspace and the control station from which the operator perform his tasks. Human performance deteriorates when the images are degraded as a result of instrumental and transmission limitations. Image enhancement is used to bring out selected qualities in a picture to increase the perception of the observer. A general purpose digital computer, an extensive special purpose software system is used to perform an almost unlimited repertoire of processing operations

높은 공간 대역폭을 위한 복소 진폭 이미징 및 디스플레이 시스템

학위논문 (박사) -- 서울대학교 대학원 : 공과대학 전기·정보공학부, 2021. 2. 이병호.빛을 파동으로 이해하면 간섭과 회절을 포함한 다양한 광학 현상을 해석 할 수 있다. 미래 기술이라 불리는 홀로그램, 3차원 이미징 및 3차원 디스플레이 시스템들은 파동의 복소진폭을 이해하고 변조함으로써 구현될 수 있다. 현존하는 광공학 장치를 넘어서는 파동 광학에 기반한 광공학 장치들을 상용화 및 발전시키기 위해 많은 연구가 진행되어왔지만, 지금껏 구현된 장치들은 공간 대역폭 (space-bandwidth product)의 제한으로 인해 그 성능이 대중의 기대에 부합하기 어려움을 겪고있다. 본 논문은 복소 진폭 이미징 및 디스플레이 시스템에서 공간 대역폭을 향상 시키는 방법을 제안한다. 복소 진폭 변조 시스템의 성능은 광학 시스템의 정보량을 나타내는 공간 대역폭에 의해 제한된다. 이 공간 대역폭을 향상시키기 위하여 저자는 다양한 다중화 기술을 적용하며, 동시에 다중화된 정보를 분리하는 알고리즘과 장치를 고안한다. 첫번째로 디지털 홀로그래피 기술에 공간 주파수를 다중화해 대역폭을 효율적으로 활용하는 방법을 고안하여 획득된 홀로그램의 촬영 영역을 증가시킨다. 두번째로, 단일 촬영 푸리에 타이코그래피 (single-shot Fourier ptychography) 기술에서는 광 조사 다중화를 사용하여 이미지 센서에 기록되는 정보의 양을 확장시킨다. 다중화 된 정보를 분해하고 복소 진폭을 획득하기 위하여 새로운 광학 시스템과 전산 알고리즘을 고안하여 해상도가 향상된 복소 진폭을 획득한다. 세번째로, 저자는 홀로그램 디스플레이에 조명 다중화 및 시분할 기술을 적용한다. 다중화 된 정보는 인간의 인지적 시간 대역폭과 제안된 시스템의 공간 필터링의 결합으로 분해된다. 구현된 홀로그래픽 디스플레이는 공간 대역폭이 확장되어 더 넓은 시야각에 삼차원 홀로그램을 제공한다. 본 논문은 작은 공간대역폭이라는 공통된 문제를 공유하는 이미징 및 디스플레이 분야의 발전에 기여할 것으로 기대된다. 저자는 본 연구에서 제안된 방법이 다양한 복소 진폭 변조 시스템의 성능 향상에 영감을 주며, 나아가 삼차원 계측, 홀로그래피, 가상 및 증강현실을 포함한 다양한 미래 산업에 발전에 기여할 수 있기를 기대한다.Understanding light as a wave makes it possible to interpret a variety of phenomena, including interference and diffraction. By modulating the complex amplitude of the wave, hologram, three-dimensional imaging, and three-dimensional display system, called future technologies, can be implemented that surpass the currently commercialized optical engineering devices. Although a lot of research has been conducted to develop and commercialize the wave optical system, state-of-the-art devices are still far from the performance expected by the public due to the limited space-bandwidth product (SBP). This dissertation presents the studies on high SBP for complex amplitude imaging and display systems. The performance of a complex amplitude modulating system is limited by the SBP, which represents the amount of information in the optical system. To improve the SBP of the complex amplitude in a limited amount of information, the author applies various multiplexing techniques suitable for the implemented system. In practice, the spatial frequency multiplexed digital holography is devised by efficiently allocating frequency bandwidth with dual-wavelength light sources. The author also applies illumination multiplexing to the single-shot Fourier ptychography to expand the amount of information recorded in the image sensor. Computational reconstruction algorithm combined with novel optical design allows the acquired multiplexed information to be decomposed in the imaging system, leading to improvement of size of the image or resolution. Furthermore, the author applied illumination multiplexing and temporal multiplexing techniques to holographic displays. The multiplexed information is decomposed by a combination of human perceptual temporal bandwidth and spatial filtering. The SBP enhanced holographic display is implemented, providing a more wide viewing angle. It is expected that this thesis will contribute to the development of the imaging and display fields, which share a common problem of small SBP. The author hopes that the proposed methods will inspire various researchers to approach the implementation of complex amplitude modulating systems, and various future industries, including 3-D inspection, holography, virtual reality, and augmented reality will be realized with high-performance.Abstract i Contents iii List of Tables vi List of Figures vii 1 Introduction 1 1.1 Complex Amplitude of Wave 1 1.2 Complex Amplitude Optical System 3 1.3 Motivation and Purpose of the Dissertation 5 1.4 Scope and Organization 8 2 Space-Bandwidth Product 10 2.1 Overview of Space-Bandwidth Product 10 2.2 Space-Bandwidth Product of Complex Amplitude Imaging Systems 11 2.3 Space-Bandwidth Product of Complex Amplitude Display Systems 13 3 Double Size Complex Amplitude Imaging via Digital Holography 15 3.1 Introduction 15 3.1.1 Digital Holography 16 3.1.2 Frequency Multiplexed Digital Holography 22 3.1.3 Adaptation of Diffractive Grating for Simple Interferometer 24 3.2 Principle 26 3.2.1 Single Diffraction Grating Off-Axis Digital Holography 26 3.2.2 Double Size Implementation with Multiplexed Illumination 29 3.3 Implementation 32 3.4 Experimental Results 34 3.4.1 Resolution Assessment 34 3.4.2 Imaging Result 36 3.4.3 Quantitative 3-D Measurement 38 3.5 Conclusion 42 4 High-Resolution Complex Amplitude Imaging via Fourier Ptychographic Microscopy 43 4.1 Introduction 43 4.1.1 Phase Retrieval 45 4.1.2 Fourier Ptychographic Microscopy 47 4.2 Principle 52 4.2.1 Imaging System for Single-Shot Fourier Ptychographic Microscopy 52 4.2.2 Multiplexed Illumination 55 4.2.3 Reconstruction Algorithm 58 4.3 Implementation 60 4.3.1 Numerical Simulation 60 4.3.2 System Design 64 4.4 Results and Assessment 65 4.4.1 Resolution 65 4.4.2 Phase Retrieval of Biological Specimen 68 4.5 Discussion 71 4.6 Conclusion 73 5 Viewing Angle Enhancement for Holographic Display 74 5.1 Introduction 74 5.1.1 Complex Amplitude Representation 76 5.1.2 DMD Holographic Displays 79 5.2 Principle 81 5.2.1 Structured Illumination 81 5.2.2 TM with Array System 83 5.2.3 Time Domain Design 84 5.3 Implementation 85 5.3.1 Hardware Design 85 5.3.2 Frequency Domain Design 85 5.3.3 Aberration Correction 87 5.4 Results 88 5.5 Discussion 92 5.5.1 Speckle 92 5.5.2 Applications for Near-eye Displays 94 5.6 Conclusion 99 6 Conclusion 100 Appendix 116 Abstract (In Korean) 117Docto

Data compression techniques applied to high resolution high frame rate video technology

An investigation is presented of video data compression applied to microgravity space experiments using High Resolution High Frame Rate Video Technology (HHVT). An extensive survey of methods of video data compression, described in the open literature, was conducted. The survey examines compression methods employing digital computing. The results of the survey are presented. They include a description of each method and assessment of image degradation and video data parameters. An assessment is made of present and near term future technology for implementation of video data compression in high speed imaging system. Results of the assessment are discussed and summarized. The results of a study of a baseline HHVT video system, and approaches for implementation of video data compression, are presented. Case studies of three microgravity experiments are presented and specific compression techniques and implementations are recommended

An interactive simulation environment for end-to-end digital imaging system design and fidelity analysis

The detailed specification, implementation, and documentation of an interactive software environment based on a continuous/discrete/continuous imaging system model is presented. The purpose of the interactive environment is to support the design and performance analysis of end-to-end digital imaging systems. Development of the environment is based on the objectives of acceptable response time, large sampling grid capability, good graphical user interface design, independence from proprietary applications and portability among UNIX workstations. While one-dimensional variations of interactive design environments have been developed by the commercial active filter design community, there is little or no evidence that the increased complexity associated with the extension to two dimensions had been satisfactorily accomplished prior to the work in this dissertation. The computer time versus computer memory trade-off is discussed as it applies in this particular context, and the results of a systematic study of representation passband limits are presented. The object of the study was to determine the representation passband parameters beyond which any aliasing contribution from frequencies beyond the representation passband is invariably negligible. Validation of the environment is documented by an exhaustive consideration of simple input scenes comprised of a uniform square on a uniform background, in which the square can be arbitrarily small and arbitrarily located within the scene. The effects of sampling and the dependence of those effects on sample-scene phase are illustrated in 1-D, used as a predictor for the 2-D outcome, and then illustrated in 2-D for the purpose of comparing the projected and actual results

Design and Implementation of a FPGA and DSP Based MIMO Radar Imaging System

The work presented in this paper is aimed at the implementation of a real-time multiple-input multiple-output (MIMO) imaging radar used for area surveillance. In this radar, the equivalent virtual array method and time-division technique are applied to make 16 virtual elements synthesized from the MIMO antenna array. The chirp signal generater is based on a combination of direct digital synthesizer (DDS) and phase locked loop (PLL). A signal conditioning circuit is used to deal with the coupling effect within the array. The signal processing platform is based on an efficient field programmable gates array (FPGA) and digital signal processor (DSP) pipeline where a robust beamforming imaging algorithm is running on. The radar system was evaluated through a real field experiment. Imaging capability and real-time performance shown in the results demonstrate the practical feasibility of the implementation

Roadmap on optical security

Postprint (author's final draft