bluuebunny/crossref_metadata_2025 huggingface dataset:
High Resolution Secondary Ion Mass Spectroscopy Imaging
Authors: Levi‐Setti Riccardo , Gavrilov Konstantin L.
Published: October 2003

Several modern microanalytical techniques strive to describe the chemical composition of materials by images at ever increasing spatial resolution and sensitivity. Digital micrographs that depict the two‐dimensional distribution of selected constituents (analytical maps) across small areas of a sample are one of the most effective vehicles for recording the retrieved information quantitatively. One technique in particular, secondary ion mass spectroscopy or, more appropriately, spectrometry (SIMS) imaging, has been advanced during the last two decades to reach analytical image resolution of a few tens of nanometers. High‐resolution SIMS imaging has become practical due to the development of finely focused scanning ion probes of high brightness, incorporated in scanning ion microscopes or microprobes (SIM), as is illustrated in this context. SIMS images are shown that embody a wealth of correlative interwoven information in a most compact form. These can be thought of as two‐dimensional projections of an abstract multidimensional space that encompasses the spatial dimensions (physical structure), the mass or atomic number dimension (chemical structure), and, as a further variable, the concentration of each constituent in a sample (quantification).

In this article, the fundamental principles that underlie the formation of SIMS images, the requirements and limitations in attaining high spatial resolution (<100 nm), the engineering details of a state‐of‐the‐art SIM, and a number of applications, illustrated by images, in the materials sciences are reviewed.
High Speed Photographic Imaging
Authors: Davidhazy Andrew
Published: October 2003

High‐speed photography is a specialty within the broad discipline of scientific photography that is used for making visible and possible quantitative evaluations of events that transpire over periods of time much too short for visual perception even when aided by the processes of image recording by normal photographic cameras. The time frame of certain events can be so short that sometimes neither qualitative nor, more importantly, quantitative evaluation of an event is possible using conventional photographic techniques.

When the lifetime of events of interest is very short, both higher shutter speeds and framing rates than are normally available on standard cameras are required. When such events happen in adverse and hostile environments, this calls additionally for photographic systems ruggedized for such conditions. In addition, when the motion of subjects over time is of interest or there is a desire to record subjects that are too small for the unaided eye to appreciate fully, this also calls for special camera equipment.
Human Visual System—Color Visual Processing
Authors: Fairchild Mark D.
Published: October 2003

This chapter covers the basic structure and function of the human visual system with respect to people's perception of color, and procedures to quantify those color perceptions, colorimetry, through the measurement and specification of light sources, materials, and human observers. specific topics addressed include: visual anatomy and physiology related to color perception, the spatial and temporal properties of color vision, color vision deficiencies, basic and advanced colorimetry, light sources and illuminants, materials, tristimulus values, CIE colorimetry, chromaticity coordinates, color spaces, color difference metrics, and color appearance models. A basic understanding of human color vision and color specification is important for imaging science and technology in order to develop insight into the design, engineering, and limitations of color imaging systems and further improve such systems. CIE colorimetry is also the fundamental basis of modern color management systems that enable device‐independent color imaging in digital systems. Since it is very difficult to cover all of this material in sufficient detail in a single article, interested readers should look to books devoted to color science for more detailed information. These reference marks are listed.
Human Visual System—Image Formation
Authors: Roorda Austin
Published: October 2003

The 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

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

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

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

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.

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

Imaging 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

The 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

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

Ink‐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

The 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

Fluorescence 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.
Lightning Locators
Authors: Shirer Hampton N. , Roeder William P. , Shirer Hampton W. , D'Arcangelo David L. , Hilliker Joby , Koval Joe , Magee Nathan , Mazeroski David W.
Published: October 2003

Locating lightning in real time is an old problem. Radio techniques developed in the early to mid‐twentieth century used crossed‐loopcathode‐ray direction finders(CRDF) that provide the bearing but not the range to the lightning source.Direction‐finding(DF) systems typically sense the radio signal, known asatmospherics,spherics, or ‘sferics, that is emitted by lightning and that most listeners of AM radios interpret as interference,static, orradio noise. Quite generally, lightning radiates electromagnetic pulses that span an enormous range of frequencies. In this article, theradio signalrefers to the portion of the electromagnetic spectrum that covers frequencies less than 3 × 108kilohertz (denoted kHz), or 300 GHz, and the optical signal refers to frequencies greater than 3 × 108kHz. Also, when not qualified here, electromagnetic radiation refers to the radio signal.

Lightning sensing systems have important applications in meteorology. Certainly, these systems can help to detect and forecast the arrival of thunderstorms by monitoring their positions, motions, and intensities. Such systems are also important for lightning safety and for protecting natural resources in a diverse set of real‐time applications, including fire and personnel safety, aircraft routing, missile launch decisions, power grid operation, and weather forecasting. Lightning is a significant threat to people but far too often is underrated. Lightning sensing systems, especially those that detect intracloud lightning, are being investigated as tools for predicting severe thunderstorms, including tornadoes, microbursts, and hail. Lightning data are also being investigated as possible input for small‐scale numerical weather forecast models to supplement the usual observations of pressure, temperature, humidity, and winds.

This article is not an exhaustive survey of all real‐time and research lightning location systems, but it provides a comprehensive overview of the topic. It is split into two major parts; the first reviews the many important concepts and defines the terminology used to describe them, and the second covers the different major types of operational lightning location systems by describing an example of each in detail.

Many of the lightning facts herein are documented thoroughly in the references. The methods and detection systems reviewed in this article are also described on various World Wide Web (www) sites. The addresses for many of these sites are given.
Liquid Crystal Display Technology
Authors: Crawford Gregory P. , Escuti Michael J.
Published: October 2003

As the display in most imaging systems is the final medium through which an image is rendered for manipulation and verification, an understanding of display technologies is essential to the imaging process. Because individuals working in the field of imaging science and technology may spend more time looking at a display screen than at anything else in their office or laboratory, it is imperative that it be comfortable to use and appropriate for the particular context.

Twenty years ago, system manufacturers often integrated the electronic display directly into the system to provide a complete package for a specified imaging application. Although this approach does not afford much flexibility, the display could be closely matched to a specific application because user requirements were well defined. This custom design approach enabled optimizing the graphics controller, system software, and user interface for the display, user, and application requirements. Despite the positive attributes of this “black‐box” approach, such as high performance and superior application specific image quality, closed architecture platforms tend to be more expensive and suffer from incompatibility with peripheral add‐ons and software packages not supported by the system manufacturer.

Today, the situation is dramatically different due to the continual evolution of the graphics controller interface. By mixing images with text and graphics, software developers require more from the display to support moving images without diminishing display performance for static images. The graphical capability of today's standard computer platforms has now made it unprofitable for vendors of imaging systems to develop their own displays for system‐specific tasks. End users now typically purchase a computer platform, display, and a variety of other peripherals from multiple vendors and integrate them with ease (i.e., a plug‐and‐play philosophy). In such a marketplace, one must be well educated to match display technology to application needs. This article provides the reader with a fundamental knowledge of working principles of liquid crystal displays (LCDs), their capabilities, and their limitations.
Magnetic Field Mapping
Authors: Henrichsen K. N.
Published: October 2003

Magnetic field mapping is the production of maps or images of magnetic fields in space. Magnetic field maps are needed for designing and optimizing of magnets used in particle accelerators, spectrometers (mass, nuclear magnetic resonance, and electron paramagnetic resonance), and magnetic resonance imaging systems. Magnetic field maps are also used in geologic exploration where the variations in the magnitude and direction of the earth's magnetic field are indicative of subsurface features and objects. Field mapping relies on various methods of measuring the magnetic field, generally one point at a time. These measurement methods are the main focus of this article.

It is curious to note that most measurement methods have remained virtually unchanged for a very long period, but the equipment has been subject to continual development. In this article, only the more commonly used methods are discussed. These methods are complementary and a wide variety of the equipment is readily available from industry. For the many other existing measurement methods, a more complete discussion can be found in two classical bibliographical reviews. Much of the material was presented at the CERN Accelerator School on Measurement and Alignment of Accelerator and Detector Magnets.
Foundations of Morphological Image Processing
Authors: Dougherty Edward R.
Published: October 2003

The basic morphological operations of erosion, dilation, opening, and closing are a part of every image processing toolbox. So too are many basic algorithms such as the watershed and top‐hat transforms. This article reviews the fundamental algebraic theory of mathematical morphology as applied to Euclidean set theory, the context in which it was originally conceived by Matheron and Serra from mathematical operations dating back to Minkowski and Hadwiger. Thorough knowledge of basic algebraic theory is required for anyone engaged in serious research in morphological image processing and is very beneficial for anyone interested in advanced applications.

Since its original set‐theoretic formulation, mathematical morphology has been extended to real‐valued functions and to lattice‐valued functions. These extensions take note of the fact that the operations and propositions of the algebraic theory depend on order relations. This can be seen in the direct generalization of many binary definitions and properties to lattices based on the partial order relation among sets. In many cases, the definitions in this article are extended to lattices (including real‐valued and integral‐valued functions) by changing the subset relation ⊂ to the order relationship ≤.

This article restricts attention to binary morphology.
Motion Picture Photography
Authors: Hope Thomas W.
Published: October 2003

It is not the intention of this article on motion picture photography to be all encompassing. Motion picture photography as a professional industry has many facets. In effect, this is a compendium. Subjects pertaining more closely to imaging are covered in greater detail than others not directly involving imaging. For definitions of many terms used here, consult the glossary. Motion picture photography, dating from the 1890s, is one of the oldest of modern imaging, technologies that remains current today.

Motion picture theory is simple and clear‐cut. Motion film is composed of a series of still pictures. When the still pictures are projected progressively and rapidly onto a screen, the eye perceives motion, hence they become a motion picture. This is termed
persistence of vision
. In a conventional sound motion picture, 24 individual pictures are projected onto the screen in one second. The screen is blank (black) for 1/96th second. While picture number one is blanked out, the film moves to picture number two. The eye and mind retain the image of picture number one for that fraction of a second when the screen is black. If, for example, something in motion is being photographed, the difference between image one and image two is minute. The eye and memory record a smooth transition from picture one to picture two. This is perceived as motion.

Oxygens of motion picture photography are discussed.

Photographic film used for motion pictures is normally a thin strip or ribbon. The exception is wide format films, 65 mm and 70 mm used for
wide‐screen
shows. Composition types and properties of film are detailed.

A motion picture camera is a lighttight precision instrument. All professional cameras, with a few exceptions, are operated by an electric motor. The power can be supplied by a battery in the field or ac power in the studio.

Essentially, there are two types of projectors. Both operate using the same basic configuration of picture head, optics, and shutter system. The major difference is in the film supply and take‐up system.
Particle Detector Technology for Imaging
Authors: Taylor Geoffrey N.
Published: October 2003

In this article, “particles” refer to charged particles that have enough energy to pass some significant distance through matter. The interaction of particles with matter forms the basis on which particle detectors are designed and operated. The principal process for detection is ionization of matter by the electromagnetic interaction of the moving particle. Ionization produces free charge that can be collected and detected. Electromagnetic radiation from the charged particle moving through matter may also be used to create a detectable signal. Neutral particles can be observed following their interaction with matter, producing one or several charged particles, that are subsequently detected.

The development of particle detectors has occurred within the fields of nuclear and high‐energy particle physics. In this regime, the interest lies in reconstructing particles emanating from a particle interaction or from the decay of unstable particles or nuclei. The trajectories of the detected particles are recorded to reconstruct the kinematics (momentum and energy of the particles) of the reactions being observed. The particle trajectories are sampled as the particles pass through the detector elements. The sampled track positions are used to reconstruct the full trajectory.

In addition to the kinematics of such reactions, spatial information is also important, especially when determining the distance that an unstable particle travels before decaying. The decay time distributions of unstable particles follow the exponential statistical time distributions of radioactive decays whose half‐lives or lifetimes are characteristic of the particle or the nuclear state being studied. For sufficiently long lifetimes, the combination of track length before decay and the reconstructed kinematics of the decay products are used to determine the decay time of individual decays. The ensemble of data is then used to extract the characteristic lifetime of the particle from the distribution of the individual decays.

The most common particles that can be tracked and imaged include electrons, protons, some nuclei, muons, pions, kaons, and neutrinos. High‐energy photons (X rays and gamma rays) also have particlelike properties and provide great utility in imaging applications. The source of the particles can be radioactive tracers distributed within the object being imaged or an external source such as a radioactive source, a reactor, an accelerator, or cosmic rays.
Photodetectors
Authors: Wadsworth Mark
Published: October 2003

Photons impinging upon matter interact in a manner determined by the nature of the chemical bonds in the material and the energy of the incident photons. Interacting photons may be reflected, refracted, diffracted, transmitted, or absorbed. Each of these phenomena can be used to measure some parameter of interest in chemical analysis. Photo‐assisted chemical analytical techniques require an accurate, sensitive method of photon detection and quantification. Photographic film proved to be the first useful method for such evaluations. Later, photomultiplier tubes provided the means to improve many photo‐analytical techniques. With the advent of semiconductor technology, numerous single‐element, broad‐spectrum photodetecting devices were developed and applied to the task. Most recently, photodetector technology has entered the age of high density integration. Large‐area photon detectors are becoming commonplace in most analytical equipment. The advances afforded by these devices have allowed for significant improvements in the performance of systems designed for photo‐analytical chemical analysis in general, and specifically for spectroscopic‐based equipment. A working knowledge of the operation and limitations of photodetectors is therefore necessary for the modern chemist.

Photodetector devices convert electromagnetic radiation or photons to electric signals which can be processed to obtain the spectral, spatial, and temporal information inherent in the radiation. Photodetectors, may be operated in many modes. The more popular ones are photoconductors, photodiodes, charge‐transfer devices, and pyroelectrics. The detectors may be used as single elements such as in street light controls, film camera exposure control, or motion detectors for security. Photodetectors also find application in the form of linear arrays used in analytical spectrometers, night‐vision equipment, in small, low cost spectrometers for the control of building ventilation and environmental pollution monitoring or configured as large matrix arrays in video cameras. This chapter includes the following topics: Principles; figures of Merit; photodetector modes of operation; detector fabrication and performance; and health and safety factors.
RF
Magnetic Field Mapping
Authors: Hornak Joseph P.
Published: October 2003

Radio‐frequency (RF) magnetic field mapping is the imaging of oscillating magnetic fields in space. The title of this article implies RF mapping, however, the technique is applicable to both higher frequency microwaves and lower audio frequency electromagnetic waves.

Five mapping techniques are presented in this article. They were developed for mapping the oscillating magnetic fields (standing waves) associated with inductive–capacitive–resistive (LCR) circuits, such as cavity resonators and resonant coils used in magnetic resonance spectroscopy and imaging. LCR circuits store energy alternately in the capacitive element as electrical fields and in the inductive element as magnetic fields. The oscillating magnetic fields form a standing wave within the volume of the inductor. The electrical fields are either zero or separated in space from the magnetic fields, and hence generally are not detected in these circuits. This point is worth noting because some of the techniques presented in this article cannot distinguish oscillating magnetic and electrical fields.

Because of the magnetic resonance application of these techniques, much of the magnetic resonance symbolism has been adopted, and some basic magnetic resonance theory will be presented.

The mapping techniques are divided into two general categories: probe and imaging techniques. Probe techniques produce field values at discrete points in space that can be used to generate a
B
1
map. Imaging techniques produce an image directly. The method depends on the proportionality of the intensity of a pixel in this image to the magnetic field at the corresponding point in space.
Scanning Acoustic Microscopy
Authors: Tittmann Bernhard R. , Miyasaka Chiaki
Published: October 2003

This article is an overview of scanning acoustic microscopy, which is one of the more advanced ultrasonic imaging technologies. The scanning acoustic microscope (SAM) uses ultrasound to produce enlarged images of the microscopic structures of materials. In other words, the SAM is an instrument that subjects an object to ultrasound and detects the variations of the elastic properties of the object. The elastic properties are determined by the molecular arrangement of the material, molecule size, intermolecular force or the like, and each material has its unique characteristics. Accordingly, each object reacts in its own peculiar way when subjected to ultrasonic waves. The waves received from the object can be converted into an image. Because ultrasonic waves can penetrate into an object's interior, the surface and also the interior can be visualized.

The contents of this article are as follows: First, the need in industry for this process is described. Second, the history of the development of the SAM is illustrated in brief. Third, the basic theory of ultrasonic imaging used in the SAM is depicted, as well as the basic theory of the implements used in the SAM. Furthermore, theV(z) curve method for material characterization is described. Selected images are given for a better understanding of the sections.
Silver Halide Detector Technology
Authors: Hailstone Richard
Published: October 2003

This article describes the basic construction and operation of silver halide materials as image recording devices. The detector consists of silver halide microscrystals coated in a gelatin–water mixture on either a transparent or paper support. Strictly speaking the resulting suspension of silver halide microcrystals in aqueous gelatin is classified as a dispersion but early on in the development of photography it was called an “emulsion.” Emulsion is used in this article. A latent image is formed via a photochemical change of the microcrystal. The visible image is created through an image processing step in which those microcrystals that have received sufficient light “blacken” as they are transformed from silver halide to metallic silver.

The microcrystals, also called “grains,” are prepared in a variety of shapes and size distributions to accommodate a variety of applications. Over the range of applications, the microcrystal size varies from a few tenths of a micron diameter to several microns diameter. Sensitivity, or speed, increases with increasing grain size, so higher speed films must necessarily use larger grains. Materials intended for image capture need to produce a distinguishable output over a wide range of inputs arid so a polydisperse size distribution is used. On the other hand, materials for image display, such as prints, need to respond only over a relatively narrow range of inputs so a monodisperse size distribution is often used.
Single Photon Emission Computed Tomography (SPECT)
Authors: Madsen Mark T.
Published: October 2003

SPECT (Single photon emission computed tomography) is a diagnostic imaging modality that produces tomographic slices of internally distributed radiopharmaceuticals. It is routinely used in the diagnosis of coronary artery disease and in tumor detection. Projection views of the radiopharmaceutical distribution are collected by one or more scintillation cameras mounted on a gantry designed to rotate about a patient lying horizontally on a pallet. The projection information is mathematically reconstructed to obtain the tomographic slices. Most clinical SPECT studies are qualitative with simplistic corrections for attenuation and scattered radiation. Quantitative SPECT requires corrections for attenuation, scatter and spatial resolution, although these have not been routinely implemented in the past because of their computational load. SPECT instrumentation has evolved to include coincidence imaging of positron emitting radiopharmaceuticals, specifically18F Fluorodeoxyglucose.

SPECT imaging is expected to play a continuing important role in medical imaging. Future improvements in SPECT instrumentation are likely to include new detectors and collimation schemes. The primary motivating factor in SPECT imaging will continue to be the creation and implementation of new radiopharmaceuticals. SPECT use in tumor imaging will probably experience the largest growth. Applications will include treatment planning for internal radiation therapy as well as diagnostic studies.