bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human Visual System—Image Formation
Authors: Roorda Austin 
Published: October 2003

AbstractThe ultimate stage in most optical imaging systems is the formation of an image on the retina, and the design of most optical systems takes this important fact into account. For example, the light output from optical systems is often limited (orshouldbe limited) to the portion of the spectrum to which people are most sensitive (i.e., the visible spectrum). The light level of the final image is within a range that is not too dim or bright. Exit pupils of microscopes and binoculars are matched to typical pupil sizes, and images are often produced at a suitable magnification, so that they are easily resolved. One even incorporates focus adjustments that can adapt when the user is near‐ or farsighted. Of course, it is understandable that a man‐made environment is designed to fit within sensory and physical capabilities. But this process is not complete. There is still much to know about the optical system of the human eye, and as understanding of the eye increase better ways to present visual stimuli and to design instruments are learned.This article focuses on the way images are formed in the eye and the factors in the optical system that influence image quality.
Human Visual System—Spatial Visual Processing
Authors: De Valois Karen K. , De Valois Russell L. 
Published: October 2003

Abstract
The human visual system is a remarkably versatile and powerful spatial image processor. The eye itself is only a small part of the visual mechanism. The task of analyzing and comprehending the visual world is so complex that the brain devotes between one‐third and one‐half of the entire cerebral cortex to solving it: all of the occipital lobe and large parts of the parietal, temporal, and frontal lobes as well. To appreciate the magnitude of the task of visual processing, it is useful to consider some of the problems that the visual system must address in the course of analyzing visual images.
Solutions to initial problems are discussed. Details on the visual processing of the eye including visual analysis and coding strategies and cortical processing are given.
Feature Measurement
Authors: Russ John C. 
Published: October 2003

Abstract
The measurement of images is used in many fields at magnifications from the atomic to the cosmic. Generally, the purpose of measurement is to extract numerical values from the image that will meaningfully represent either the structure or the objects (features) present in the field of view. The quantity of data is greatly reduced from the original collection of pixels to a comparatively small set of measurements. Measurements fall into two major categories: global measurements on the entire image field that describes the structure and on each of the individual features present. Interpretation of those measurements requires statistical and stereological techniques which lie beyond the scope of this article. Stereology is the science of geometrical probability that relates the parameters of three‐dimensional structures and objects to the measurements that are accessible in two‐dimensional images. Typical measurements used in stereological calculations are the total area fraction of the structure of interest, the length of the boundary surrounding the selected regions, and the number of objects present (or simply the number of intersections between the structure and some appropriate grid of lines).
Measurements of individual objects within a field of view fall naturally into four groups: measures of size, density (or anything else derived from the pixel brightness values), position, and shape. Within each category are several choices of specific parameters. In all cases, features that intersect the edge of the field of view cannot be measured accurately since their total extent is not shown. Omitting features that touch the edges of the image would bias the data, since large features are more likely to intersect the edges. This bias can be corrected either by restricting the measurements to a region smaller than the entire image, so that features crossing the boundary of the measurements region do not reach the edge of the image and can be measured, or by making a statistical correction to the data based on the size of each measured feature.
Imaging Science in Overhead Surveillance
Authors: Fiete Robert D. 
Published: October 2003

Abstract
Overhead surveillance has come a long way since Tournachon (“Nadar”) collected the first aerial photographs from a hot air balloon in 1858. The invention of the plane made overhead surveillance more practical. Images from space began with Explorer IV in 1959.
Today an increasing amount of overhead surveillance imagery is collected by systems that do not require pilots. Satellites are used to collect data high above the earth. (UAVs) (unmanned aerial vehicles) are being used to collect information at lower altitudes. Overhead surveillance systems continue to provide environmental and meteorological data to the scientific community as well as important intelligence data from areas that are difficult to access.
Linking together many steps in an image chain creates the final image product produced by an overhead surveillance system. Each link plays a vital role in the final quality of the image. This article discusses the various steps.
Surveillance systems are generally categorized by the wavelength region of the electromagnetic spectrum that they image. The earliest cameras used black and white film that captured panchromatic images, i.e., film that is sensitive to the visible portion of the electromagnetic spectrum. Even with CCD (charged coupled devices) detectors today, black and white images are the most common because the light is captured over a broad spectrum of wavelengths, thus allowing a high enough signal to collect high‐resolution images. Visible imaging systems generally acquire images using the sun as the illumination source.
After the image data has been downlinked to the groundstation and decompressed, it may be hard to interpret the image due to low contrast, blurred edges, streaks from sensitivity differences between detectors, failed detectors, and discontinuities at the segment boundaries. Image processing techniques can be used to optimize the visual interpretability of the image data. Calibration is performed to remove the streaks, and the data from each detector segment are processed to synthesize an image collected with a single continuous detector array. The image is also processed to remove any image motion effects, such as vehicle oscillation, and geometric distortions that might occur. The image data can also be processed to a specific mapping spatial resolution. The utility of an image should not be equated with quality of the image. For example, geographic surveys can be performed better with overhead images that trade‐off lower resolution for a larger area of coverage. The image acquired at the lower altitude has more detail that can be resolved on the ground, but much of the surrounding information is lost, which may be very important to understand the context of the objects on the ground.
Imaging Science in Art Conservation
Authors: Arney J. S. , Arney L. E. 
Published: October 2003

AbstractMuseum professionals regularly apply a variety of imaging technologies to artistic and historic objects. The particular imaging technique applied is determined in part by the intended use of the image. Ordinary photography, for example, is used to illustrate the approximate appearance of objects in a museum collection, and optical microscopy is commonly used to identify pigments in an oil painting. The choice of an imaging technique is also influenced by the anatomic structure of the object. For example, traditional drying oils used as vehicles and varnishes in oil paintings fluoresce more strongly as they age. Thus, a photograph taken under ultraviolet illumination is often used to reveal and document discontinuities between original and restored or altered regions of a painting. On occasion, imaging techniques of this kind have been used to uncover fakes and forgeries, but such applications of imaging to museum studies are rare. By far, the most important use of imaging technologies is to archive information about the object and to extract information about the structure of the object. Archiving preserves information and makes information more readily available to scholars, and structural analysis provides guidance to museum professionals in conserving and restoring objects. This article reviews imaging techniques intended for these two purposes.Museum professionals regularly apply a variety of imaging technologies to artistic and historic objects. The particular imaging technique applied is determined in part by the intended use of the image. Ordinary photography, for example, is used to illustrate the approximate appearance of objects in a museum collection, and optical microscopy is commonly used to identify pigments in an oil painting. The choice of an imaging technique is also influenced by the anatomic structure of the object. For example, traditional drying oils used as vehicles and varnishes in oil paintings fluoresce more strongly as they age. Thus, a photograph taken under ultraviolet illumination is often used to reveal and document discontinuities between original and restored or altered regions of a painting. On occasion, imaging techniques of this kind have been used to uncover fakes and forgeries, but such applications of imaging to museum studies are rare. By far, the most important use of imaging technologies is to archive information about the object and to extract information about the structure of the object. Archiving preserves information and makes information more readily available to scholars, and structural analysis provides guidance to museum professionals in conserving and restoring objects. This article reviews imaging techniques intended for these two purposes.
Imaging Sciences in Forensics and Criminology
Authors: Vorder Bruegge Richard W. 
Published: October 2003

AbstractImaging and imaging technologies play an important role in forensics and criminology. Photographs and other visual recordings represent an efficient means for documenting the condition of a subject at an instant in time. The subjects of such images may include accident and crime scenes, items of evidence in a laboratory, victims, or suspects. Such visual records are easily preserved for later use by investigators, eyewitnesses, forensic scientists, court officials, and juries. The thorough and complete photographic recording of a scene, person, or item of evidence also enables investigators and forensic scientists who were not present when the images were recorded to develop meaningful information long after the person, scene, or item was photographed and may have lost all traces of a prior condition.The recording of this prior condition can be critical in many investigations due to the transient nature of the subjects or scenes. Photographs may also help eyewitnesses remember relevant facts they might otherwise discount or forget.In other instances, imaging technologies may provide the only means for revealing or recording evidence. Surveillance imagery depicting the robbery of a bank may be used to document the actions of the robbers, which might not otherwise have been witnessed. In the laboratory, forensic imaging techniques may be used to produce a visible record of writings that are not apparent to the naked eye through the selective use of lighting, specialized photographic papers, and filters. Image processing may be used to extract critical details or reduce extraneous noise from an image, thus helping clarify the picture.Finally, images may also be used as the subject of forensic analysis to derive information above and beyond that immediately apparent to the untrained eye. Such analyses may include comparing photographs of a latent impression with fingerprints of a known suspect or determining the height of a robber depicted in a surveillance image.The range of imaging technologies used in law enforcement and forensic applications encompasses a broad field from traditional silver‐based film to analog video, and now includes digital still and digital video imaging. Of particular importance to law enforcement today are technologies such as scanners and digitizers (or “frame grabbers”) that convert traditional film and analog video imagery to a digital format. Once in a digital format, such images may be analyzed using digital processing techniques.The range of situations in forensics and criminology in which imaging technologies play a role is wide. For simplicity, these situations may be divided into several general categories: field‐based photography and video, laboratory‐based photography, forensic image processing, and laboratory image analysis. These categories are rarely independent of one another, however, because images acquired in the field or in a laboratory frequently become the subject of forensic image processing or image analysis.
Imaging Science in Astronomy
Authors: Kastner Joel H. 
Published: October 2003

AbstractThe vast majority of information about the universe is collected via electromagnetic radiation. This radiation is emitted by matter distributed across tremendous ranges in temperature, density, and chemical composition. Thus, more than any other science, astronomy depends on innovative methods to extend image taking to new, unexplored regions of the electromagnetic spectrum. To bring sufficient breadth and depth to their studies, astronomers also require imaging capability across a vast range in spatial resolution and sensitivity, with emphasis on achieving the highest possible resolution and signal gain in a given wavelength regime. This simultaneous quest for better wavelength coverage and ever higher spatial resolution and sensitivity represents the driving force for innovation and discovery in astronomical imaging.Classical astronomy—for example, the search for new solar system objects and the classification of stars—is still largely conducted in the optical wavelength regime (400–700 nm). This has been the case, of course, since humans first imagined the constellations, noted the appearance of “wandering stars” (planets), and recorded the appearance of transient phenomena such as comets and novae. During the latter half of the twentieth century, however, a revolution in astronomical imaging took place. This relatively brief period in recorded history saw the development and rapid refinement of techniques for collecting and detecting electromagnetic radiation across a far broader wavelength range, from the radio through γ rays. Just as these techniques have reached maturation, astronomers have also developed the means to surmount apparently fundamental physical barriers placed on image quality, such as the distorting effects of refraction by Earth's atmosphere and diffraction by a single telescope of finite aperture. The accelerating pace of these innovations has resulted in deeper understanding of, and heightened appreciation for, both the rich diversity of astrophysical phenomena and the fundamental, unsolved mysteries of the cosmos.
Imaging Science in Biochemistry
Authors: Guex Nicolas , Schwede Torsten , Peitsch Manuel C. 
Published: October 2003

Abstract
Research in biology aimed at understanding the fundamental processes of life and is both an experimental and an observational science. Over the course of the last century, all classes of biomolecules relevant to life have been discovered and defined. This article describes how protein structures are elucidated and represented. Biology progressed from cataloging of species and their life styles to analyzing their underlying molecular mechanisms. Among the molecules required by life, the proteins represent certainly the most fascinating class, as they are the actual “working molecules” involved both in the processes of life and the structure of the living beings. Proteins carry out diverse functions including signaling and chemical communication (e.g., kinases and hormones), structure (keratin and collagen), transport of metabolites (hemoglobin), and transformation of metabolites (enzymes).
Observation and analysis, in contrast to modeling and simulation, are the main approaches used in biology. The development of microscopes permitted observation of the smaller members of the living kingdom and hence of the cells and the organelles they contain. However, observing macromolecules on an atomic level could not be achieved by visible light or electron microscopy. Recent advances allowed imaging of the outer shape of large molecular entities at low resolution.
Consequently, indirect methods that reveal molecular organization in a crystal (x‐ray crystallography) or interactions between atoms (NMR) have been developed and are routinely used. The reader has thus to keep in mind that all images are not direct observations. Images in this article were carefully selected to present a broad view of the various mode of representation used by scientists to help them unravel protein structure and function. Several programs to generate such images are available, and most of them are able to display or generate many of the different representations described in this article.
Ink Jet Printing for Organic Electroluminescent Display
Authors: Yang Yang , Chang Shun‐Chi , Bharathan Jayesh , Liu Jie 
Published: October 2003

AbstractInk‐jet printing (IJP) technology is a popular technology for desktop publishing. Since some of the conducting (or conjugated) organic molecules and polymers are solution processible, IJP becomes an ideal method for printing polymer–organic light‐emitting diodes with high resolution. In this article, the current status of the application of ink‐jet printing technology to the organic electroluminescent displays is briefly reviewed. Subsequently, the hybrid ink‐jet printing technology, which consists of an ink‐jet printed layer in conjunction with another uniform spin‐coated polymer layer (which serves as a buffer layer to seal the pin holes between the ink droplets) is introduced. This HIJP technology has been successfully applied to the fabrication of polymer light‐emitting logos, multicolor polymer–organic light‐emitting diodes, and built‐in shadow masks for cathode patterning of pixelated polymer LEDs.
Instant Photography
Authors: Mervis Stanley H. , Walworth Vivian K. 
Published: October 2003

AbstractThe term instant photography originally referred to one‐step film processes that provide finished photographs within a minute after exposure of a silver halide film. The processing of each film unit is initiated in the camera immediately after the film has been exposed. Such processes are outwardly dry, and the reagent is usually provided as part of the film unit. Processing proceeds rapidly under ambient conditions, as opposed to the multistep darkroom processes that require precise time and temperature control. The technology of instant photography has been extended to include the application of similar chemistry to films wherein processing may be delayed for a time after exposure.The advent of digital photography has further expanded the concept of instant photography. Now, CCD cameras make it possible to make an exposure, preview the resulting picture within seconds, and generate a corresponding color or black‐and‐white print within a few minutes. Furthermore, the major companies that provide instant films are now creating so‐called hybrid systems that use both digital imaging and imaging on film to produce a variety of rapidly generated images. All such systems seek to enable the photographer to create a finished photograph under ambient conditions so as to view and judge the results quickly.This article emphasizes silver halide instant films and the cameras that expose and process these films. These were the predominant instant systems at the start of the twenty‐first century. The terminstant photographyas used herein refers to these film‐based systems. Also included in this article are examples of the rapidly emerging digital/film imaging systems. An incentive for such systems is the convenience of immediate hard copy along with a digital record. Examples include digital/film imaging and digital camera/printer combinations.The discussion notes relevant low‐speed reprographic systems, usually described as diffusion transfer reversal (DTR) processes, that use silver halide photosensitive layers and follow image‐forming chemistry somewhat analogous to that of instant processes.
Laser‐Induced Fluorescence Imaging
Authors: Allison Stephen W. , Partridge William P. 
Published: October 2003

AbstractFluorescence imaging is a tool of increasing importance in aerodynamics, fluid‐flow visualization, and nondestructive evaluation in a variety of industrial circumstances. It is a means for producing two‐dimensional images of real surfaces or fluid cross‐sectional areas that correspond to properties such as temperature or pressure. This article discusses three major laser‐induced fluorescence imaging techniques: Planar laser induced fluorescence; phosphor thermography are pressure‐sensitive paint.Since the 1980s, planar laser induced fluorescence (PLIF) has been used for combustion diagnostics and to characterize gas and liquid phase fluid‐flow situations. Depending on the application, the technique can determine species concentration, partial pressure, temperature, flow velocity, or flow distribution‐visualization. Phosphor thermography (PT) is used to image surface temperature distributions. Fluorescence imaging of aerodynamic surfaces coated with phosphor material for thermometry purposes dates back to the 1940s and development of the technique continues today. Imaging of fluorescence from pressure‐sensitive paint (PSP) is a third diagnostic approach to aerodynamic and propulsion research discussed here and it has received much attention during the past decade. These three methodologies appear to be the primary laser‐induced fluorescence imaging applications outside medicine and biology. PLIF is more developed than the PT or PSP applications.