Theory Of Image Formation Research Articles

City Image Shaping Elements in Manado’s Megamas

The Megamas area encompasses 37 hectares of reclaimed beachfront land, hosting malls, hotels, and recreational spaces vital for bolstering tourism in Manado. Positioned facing Bunaken Island, Megamas stands as a must-visit destination for tourists. Leveraging Kevin Lynch's theory of city image formation, which comprises landmarks, paths, districts, nodes, and edges, this study aims to scrutinize the components shaping the urban identity of Megamas Manado. Employing qualitative methods, the research commenced with on-site observations to gain nuanced insights, followed by questionnaire administration to gauge public perceptions regarding the five elements of city image formation. The findings highlight Megamall as the predominant landmark, with adjacent public spaces serving as nodes, and corridors like Jl. Piere Tendean and thoroughfares such as Jl. E. E. Mangindaan and Jalan K.H. Abdurrahman Wahid acting as pathways. Moreover, shopping centers emerge as prominent districts within the Megamas area.

Influences of the underlying dimensions of destination image on destination loyalty in a cultural heritage destination

ABSTRACT The “cognitive-affective-conative” theory was used to explain the relationship between the destination image and loyalty to a cultural heritage site. After a systematic synthesis of 34 pertinent studies and in-depth interviews, the study applied structural equation modeling to a dataset of 424 respondents. This study identified three components of the destination image: cognitive, affective, and conative. The underlying components of the cognitive image were validated using a second-order measurement model, which discovered significant associations. The results revealed that the cognitive image influenced the affective image and destination loyalty. This study contributes to the theory of heritage destination image formation.

Invited article: X-ray phase contrast imaging in inertial confinement fusion and high energy density research.

X-ray phase contrast imaging (XPCI) provides enhanced image contrast beyond absorption-based x-ray imaging alone due to refraction and diffraction from gradients in the object material density. It is sensitive to small variations in density, such as internal voids, cracks, grains, defects, and material flow, as well as to stronger density variations such as from a shock wave. Beyond its initial use in biology and materials science, XPCI is now routinely used in inertial confinement fusion (ICF) and high energy density (HED) research, first to characterize ICF capsules and targets, and later applied in dynamic experiments, where coherent x-ray sources, ultrafast x-ray pulses, and high temporal and spatial resolution are required. In this Review article, XPCI image formation theory is presented, its diverse use in ICF and HED research is discussed, the unique requirements for ultrafast XPCI imaging are given, as well as current challenges and issues in its use.

Abbe’s Theory and its Introduction in Spain: The Use of Instruments for Scientific Demonstrations

Abstract The theory of image formation in a microscope proposed by Ernst Abbe changed the scientific approach to microscopy. Though the theory had many detractors, his new approach led to a technological revolution in the design and construction of high-quality microscopes. It paved the way for new discoveries in the fields of biology and medicine. Joaquín María de Castellarnau, was a contemporary connoisseur of Abbe’s ideas who decided to disseminate them in Spain through various publications and training courses. In his lectures, he used various devices for practical demonstrations that allowed some concepts of the new theory to be better understood. At the Museo Nacional de Ciencias Naturales in Madrid (MNCN–CSIC), one such original and unusual instrument designed by Abbe and used by Castellarnau has been preserved in perfect condition. Castellarnau used this instrument for various experiments that helped clarify the most complex points of Abbe’s theory. In this work, we explore how the context in which science developed in Spain favoured practical activities to demonstrate new scientific theories, such as Abbe’s in the early twentieth century.

Study of weld pool monitoring system based on spatial filtering

The observable information of the welding process mainly includes the weld pool, weld seam, and arc length, which can be used to predict the penetration depth, perform weld tracking, and provide early warning of weld defects. Welding monitoring technology based on machine vision has been widely researched to improve the quality and efficiency of welding. This paper proposes a novel weld pool image acquisition system based on spatial filtering and Abbe’s theory of image formation. A high-pass spatial filter was designed to eliminate the low frequency background noise so that the contour of the weld pool, weld seam, and arc shape were acquired. Compared with the weld pool monitoring system based on an optical filter, this method more effectively solved the problem of the large radiation gradient in the weld pool area, and the weld pool could be more clearly observed. It provided a new method to image the weld pool image system with the advantages of low cost and ease of implementation.

Wave theory of virtual image [Invited

The super resolution effect with virtual image was discovered about ten years ago using micron-sized transparent spherical dielectric particles. However, within the range of the corresponding size parameters, the simple approximation of geometric optics is not valid. Correct description of the virtual image needs the wave theory. Here we developed a novel theoretical method based on the wave theory of virtual image formation within a transparent dielectric sphere and discussed a few unusual effects arising in the frame of the wave theory.

Nonparaxial Mie Theory of Image Formation in Optical Microscopes and Characterization of Colloidal Particles

We derive an explicit partial-wave (Mie) series for the image of a dielectric microsphere collected by a typical infinity-corrected microscope. We model the propagation of the illumination and scattered vector fields through the optical components of the microscope by using the angular-spectrum theorem with the help of Wigner rotation matrix elements, allowing us to identify the contribution from spin-orbit helicity reversal. We consider a high numerical aperture objective well beyond the validity range of the paraxial approximation. The spherical aberration introduced by refraction at the planar interface between the sample and the glass slide is fully taken into account. By comparing our theoretical model with images of colloidal particles placed at different positions with respect to the objective focal plane, we characterize their radii and refractive index. We employ polystyrene microspheres with a known refractive index in order to fit the transverse attenuation length describing the transmission loss of the scattered field. As an application, we measure the radius and refractive index of individual silica beads. We compare the result for the radius with an independent measurement using high-resolution scanning electron microscopy. To validate the result for the refractive index, we develop a second method, independent of the theoretical model, based on the image contrast in glycerin-water solutions. In all cases we find very good agreement between our method and the validation procedures. In addition, the nonparaxial theory provides a reliable description of the images found for all focal-plane positions and for both polystyrene and silica microspheres. Our approach allows a common optical microscope to be used to measure the refractive index and radius of spherical particles covering the entire size range from the Rayleigh regime to the ray optics one.

Quantitative phase microscopy using quadriwave lateral shearing interferometry (QLSI): principle, terminology, algorithm and grating shadow description

Quadriwave lateral shearing interferometry (QLSI) is a quantitative phase imaging technique based on the use of a diffraction grating placed in front of a camera. This grating creates a wire-mesh-like image, called an interferogram, that is postprocessed to retrieve both the intensity and phase profiles of an incoming light beam. Invented in the 90s, QLSI has been used in numerous applications, e.g. laser beam characterization, lens metrology, topography measurements, adaptive optics, and gas jet metrology. More recently, the technique has been implemented in optical microscopes to characterize micro and nano-objects for bioimaging and nanophotonics applications. However, not much effort has been placed on disseminating this powerful technology so far, while it is yet a particularly simple technique. In this article, we intend to popularize this technique by describing all its facets in the framework of optical microscopy, namely the working principle, its implementation on a microscope and the theory of image formation, using simple pictures. We also provide and comment on an algorithm for interferogram processing, written in Matlab. Then, following the new extension of the technique for microscopy and nanophotonics applications, and the deviation from what the technique was initially invented for, we propose to revisit the description of the technique, in particular, by discussing the terminology, insisting more on a grating-shadow description rather than a quadriwave process, and proposing an alternative appellation, namely ‘grating shadow phase microscopy’ or ‘grating-assisted phase microscopy’.

Can publicly visible pro-environmental initiatives improve the organic environmental image of destinations?

Destination image formation theory postulates that the way tourists perceive a destination – the destination’s image – affects tourists’ destination choice. Organic destination image – which develops naturally, without an active effort by anyone to shape destination image – is more powerful than destination image induced through marketing because tourists are sceptical about the information conveyed to them through marketing communication channels. Theory predicts that destinations cannot control organic image. We challenge this assumption by hypothesizing that visible environmental initiatives at the destination are positively associated with the organic destination image of being environmentally sustainable. Results indicate that destinations may indeed be able to proactively and deliberately manage their organic image. Tourists who notice pro-environmental initiatives at the destination and pay attention to them perceive the destination as more environmentally friendly and sustainable when they depart. With organic image being a key driver of destination choice, implementation of pro-environmental initiatives becomes a rational marketing investment. This is particularly important given the increasing environmental concern of consumers. The invaluable side effect of redirecting “green marketing dollars” towards “green action dollars” is the improved environmental performance of the destination, which contributes to the United Nations Sustainable Development Goals.

Learning to do multiframe wavefront sensing unsupervised: Applications to blind deconvolution

Context. Observations from ground-based telescopes are severely perturbed by the presence of the Earth’s atmosphere. The use of adaptive optics techniques has allowed us to partly overcome this limitation. However, image-selection or post-facto image-reconstruction methods applied to bursts of short-exposure images are routinely needed to reach the diffraction limit. Deep learning has recently been proposed as an efficient way to accelerate these image reconstructions. Currently, these deep neural networks are trained with supervision, meaning that either standard deconvolution algorithms need to be applied a priori or complex simulations of the solar magneto-convection need to be carried out to generate the training sets. Aims. Our aim here is to propose a general unsupervised training scheme that allows multiframe blind deconvolution deep learning systems to be trained with observations only. The approach can be applied for the correction of point-like as well as extended objects. Methods. Leveraging the linear image formation theory and a probabilistic approach to the blind deconvolution problem produces a physically motivated loss function. Optimization of this loss function allows end-to-end training of a machine learning model composed of three neural networks. Results. As examples, we apply this procedure to the deconvolution of stellar data from the FastCam instrument and to solar extended data from the Swedish Solar Telescope. The analysis demonstrates that the proposed neural model can be successfully trained without supervision using observations only. It provides estimations of the instantaneous wavefronts, from which a corrected image can be found using standard deconvolution techniques. The network model is roughly three orders of magnitude faster than applying standard deconvolution based on optimization and shows potential to be used on real-time at the telescope.

The Effect of Service Quality in the Formation of Brand Image: Fitness Center in Bekasi, West Java, Indonesia

For companies that are engaged in the service industry, quality of service is one of important factor in establishing a positive brand image. The purpose of this study is to know (1) whether or not the effect of services quality on brand image formation of Gold's Gym Bekasi, (2) direction and magnitude of services quality on brand image formation of Gold's Gym Bekasi. The theory used in this research is the theory of services quality and brand image formation theory. This study uses quantitative research methods and involves as many as 96 respondents who have become members and have exercised in Gold's Gym Grand Metropolitan Mall Bekasi. The results found that there is an influence of 76% between services quality and brand image formation of the fitness center. This study shows the direction of positive influence, where if the quality of services is improved then the brand image formation of the fitness center will also increase by 0.571. The results of this study states that the service quality of services affects the brand image formation of the Gold's Gym Bekasi.

A general theory of far-field optical microscopy image formation and resolution limit using double-sided Feynman diagrams

Optical resolution of far-field optical microscopy is limited by the diffraction of light, while diverse light-matter interactions are used to push the limit. The image resolution limit depends on the type of optical microscopy; however, the current theoretical frameworks provide oversimplified pictures of image formation and resolution that only address individual types of microscopy and light-matter interactions. To compare the fundamental optical resolutions of all types of microscopy and to codify a unified image-formation theory, a new method that describes the influence of light-matter interactions on the resolution limit is required. Here, we develop an intuitive technique using double-sided Feynman diagrams that depict light-matter interactions to provide a bird’s-eye view of microscopy classification. This diagrammatic methodology also allows for the optical resolution calculation of all types of microscopy. We show a guidepost for understanding the potential resolution and limitation of all optical microscopy. This principle opens the door to study unexplored theoretical questions and lead to new applications.

Image Formation, Deep Learning, and Physical Implication of Multiple Time-Series One-Dimensional Signals: Method and Application

Time-series 1-D signals are ubiquitous in industrial applications for monitoring and control. However, it is lacking of efficient tools to deal with simultaneously multiple time-series 1-D signals. To this end, in this article, a novel theory of image formation is proposed that converts multiple 1-D signals to 2-D images and takes advantages of convolutional neural network for feature extraction and classification of a sequence of images. A case study is carried out for the classification of working conditions in photovoltaic power systems. In total, 23 1-D signals are mapped to a sequence of 2-D images to derive six different models through image formation-based deep learning. They are tested through the outdoor experiments under time varying working conditions. We discover that physical implication in 2-D images affects significantly the classification performance such that 2-D images with the clustered currents or voltages tend to create better results while randomly arranged image patterns are prone to generate worse results. Excellent performance with an accuracy 96.09% is guaranteed when physical advantages are incorporated in the proposed tools. Driven by the deep learning approaches, the proposed tools are promising for complicated industrial applications.

Can Abbe theory of image formation be improved ?

Abbe theory of image formation can be expanded from two-dimensional to three-dimensional space. It has to consider an optical system that forms an image of a grating in an object space. It is possible to introduce various inclinations of this grating relatively the optical axis round the axis in the object plane that is parallel to its slits. In this case, the minimum resolvable period and the corresponded spatial cut off frequency of the optical system may be calculated as the functions of the angle of grating inclination, the numerical apertures and the wavelength using the idea of Abbe theory. In case of axial symmetry of the optical system, the function for calculation of the spatial cut off frequencies describes a surface in the three-dimensional space of spatial frequencies that covers the three-dimensional spatial bandwidth. The spatial harmonics with spatial frequencies inside this spatial bandwidth can pass through an optical system and they participate in formation of three-dimensional images. The other spatial harmonics cannot pass through it. This approach makes understanding and explanation of formation of three-dimensional images clearer, faster and logically completed.

Super-condenser enables labelfree nanoscopy.

Labelfree nanoscopy encompasses optical imaging with a resolution in the 100-nm range using visible wavelengths. Here, we present a labelfree nanoscopy method that combines coherent imaging techniques with waveguide microscopy to realize a super-condenser featuring maximally inclined coherent darkfield illumination with artificially stretched wave vectors due to large refractive indices of the employed Si3N4 waveguide material. We produce the required coherent plane wave illumination for Fourier ptychography over imaging areas 400 μm2 in size via adiabatically tapered single-mode waveguides and tackle the overlap constraints of the Fourier ptychography phase retrieval algorithm two-fold: first, the directionality of the illumination wave vector is changed sequentially via a multiplexed input structure of the waveguide chip layout, and second, the wave vector modulus is shortend via step-wise increases of the illumination light wavelength over the visible spectrum. We test the method in simulations and in experiments and provide details on the underlying image formation theory as well as the reconstruction algorithm. While the generated Fourier ptychography reconstructions are found to be prone to image artefacts, an alternative coherent imaging method, rotating coherent scattering microscopy (ROCS), is found to be more robust against artefacts but with less achievable resolution.

X射线散射法测量Wolter-I型掠入射望远镜的表面粗糙度

The X-ray scattering method is investigated in application of characterizing surface roughness of X-ray grazing incidence telescope. The surface figure effect on the scattering diagram of the curved rough mirror is analyzed in detail based on generalized Harvey-Shack surface scatter theory and image formation theory, when smooth-surface approximation is met and the width of the incident beam is about one tenth of spatial wavelength of the surface figure. Based on the analysis, the characterizing scheme is designed and the determination error of the one-dimensional power spectral density function due to the finite width of the receiving slit before the detector is discussed. The scheme is simulated with Zemax and the simulated results verify that the surface figure only affects the measuring accuracy of the low-spatial-frequency surface roughness. The method overcomes difficulty in measuring roughness of the grazing incidence mirror with high resolution conveniently during the development of the X-ray grazing incidence telescope.

КОНСТРУКТИВНАЯ ТЕОРИЯ ФОРМИРОВАНИЯ ИЗОБРАЖЕНИЙ ОБЪЕКТОВ В ЧАСТИЧНО-КОГЕРЕНТНОМ СВЕТЕ

The constructive (approximate) theory of image formation for one-dimensional binary objects by a partially coherent projective diffraction-limited system at any ratio of the angular sizes of a light source and an aperture diaphragm is developed. For such objects the solution of a two-dimensional task can be consolidated to one-dimensional: to calculation of integral in the form of convolution of an object with the generalized pulse response with the subsequent nonlinear transformation. It is shown that the profile of the images created in partially coherent light is defined by the threshold system performance providing reliable finding of edge position of binary objects. Approximation of this characteristic is proposed. The theory allows simple physical interpretation of the phenomena in partially coherent projective systems.

Experimental demonstration of tri-aperture Differential Synthetic Aperture Ladar

A tri-aperture Differential Synthetic Aperture Ladar (DSAL) is demonstrated in laboratory, which is configured by using one common aperture to transmit the illuminating laser and another two along-track receiving apertures to collect back-scattered laser signal for optical heterodyne detection. The image formation theory on this tri-aperture DSAL shows that there are two possible methods to reconstruct the azimuth Phase History Data (PHD) for aperture synthesis by following standard DSAL principle, either method resulting in a different matched filter as well as an azimuth image resolution. The experimental setup of the tri-aperture DSAL adopts a frequency chirped laser of about 40mW in 1550nm wavelength range as the illuminating source and an optical isolator composed of a polarizing beam-splitter and a quarter wave plate to virtually line the three apertures in the along-track direction. Various DSAL images up to target distance of 12.9m are demonstrated using both PHD reconstructing methods.

Annular dark field transmission electron microscopy for protein structure determination

Recently annular dark field (ADF) transmission electron microscopy (TEM) has been advocated as a means of recording images of biological specimens with better signal to noise ratio (SNR) than regular bright field images. I investigate whether and how such images could be used to determine the three-dimensional structure of proteins given that an ADF aperture with a suitable pass-band can be manufactured and used in practice. I develop an approximate theory of ADF-TEM image formation for weak amplitude and phase objects and test this theory using computer simulations. I also test whether these simulated images can be used to calculate a three-dimensional model of the protein using standard software and discuss problems and possible ways to overcome these.

Calibration Method for the Panel-type Multi-view Display

School of Electrical Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-744, Korea(Received April 24, 2015 : revised August 17, 2015 : accepted September 1, 2015)We propose a novel calibration method which can be applied to all kinds of panel-type multi-view displays. We analyze how the angular, the axial, and the lateral misalignment affects the 3D image quality in a panel-type multi-view display. We demonstrate the ray optics simulation with a 3-view slanted parallax barrier system using pentile display for the quantitative calculation. Based on the analysis, we propose a new alignment pattern for all kinds of panel-type multi-view displays. The proposed pattern is sensitive to all of the angular, the axial, and the lateral misalignments. The high spatial frequency images and on and off alignment in the proposed pattern help observers to calibrate the system easily. We theoretically show the generality of the proposed alignment pattern and verify the pattern with image simulations and experiments.Keywords : Multi-view display, 3D displayOCIS codes : (100.6890) Three-dimensional image processing; (110.2990) Image formation theory