Image Formation

A depth-enhanced three-dimensional integral imaging system with electrically variable image planes is proposed. For implementing the variable image planes, polymer-dispersed liquid-crystal (PDLC) films and a projector are adopted as a new display system in the integral imaging. Since the transparencies of PDLC films are electrically controllable, we can make each film diffuse the projected light successively with a different depth from the lens array. As a result, the proposed method enables control of the location of image planes electrically and enhances the depth. The principle of the proposed method is described, and experimental results are also presented.

Diffusion tensor MRI (DTI) is now a widely used modality to investigate the fiber tissues in vivo, especially the white matter in brain. An automatic pipeline is described in this paper to conduct a localized voxel-wise multiple-subject group comparison study of DTI. The pipeline consists of 3 steps: 1) Preprocessing, including image format converting, image quality check, eddy-current and motion artifact correction, skull stripping and tensor image estimation, 2) study-specific unbiased DTI atlas computation via affine followed by fluid nonlinear registration and warping of all individual DTI images into the common atlas space to achieve voxel-wise correspondence, 3) voxelwise statistical analysis via heterogeneous linear regression and wild bootstrap technique for correcting for multiple comparisons. This pipeline was applied to process data from a fitness and aging study and preliminary results are presented. The results show that this fully automatic pipeline is suitable for voxel-wise group DTI analysis.

A wide variety of imaging applications exist for 1K x 1K midwave infrared (MWIR) imagers and Nova's Variable Acuity Superpixel Imager (VASTM) technology1,2 has now progressed to this image format. This paper will demonstrate a variety of imagery from MWIR cameras using this large format "LVASI" device; the in-pixel processing used by the LVASI cameras represents the state-of-the-art for image size, total field of view, high frame rates, low data bandwidths and real-time spatial reprogrammability of focal plane arrays (FPAs). Using these devices, imaging systems may now be implemented that permit the operator to "zoom in" to regions of interest with very high spatial resolution, while covering the remainder of the total field of view (TFOV) at conventional resolutions. The bandwidth compression attainable using these sensors helps to make possible systems that can transmit their high resolution imagery through wireless interconnected networks. We present recent infrared image data that highlight numerous applications including missile detection/tracking, search/rescue and remote surveillance applications.

This paper reports on a study that was designed to investigate the knowledge about image formation exhibited by students following instruction in geometrical optics in an activity-based college physics course for prospective elementary teachers. Students were interviewed individually, using several tasks involving simple apparatus (plane and curved mirrors, lenses, and prisms). The diagrams drawn by the students and the verbal comments they made provide evidence that their knowledge can be described as an intermediate state, a hybridization of preinstruction knowledge (which is dominated by a holistic conceptualization) and formal physics knowledge. We infer from our data the core concepts and main ideas of the postinstruction students' hybrid knowledge. Finally, by comparing preinstruction and formal physics conceptualizations of image formation we argue that a strong type of knowledge restructuring (in the sense

Video-frame-rate millimetre-wave imaging has recently been demonstrated with a quality similar to that of a low-quality uncooled thermal imager. In this paper we will discuss initial investigations into the transfer of image processing algorithms from more mature imaging modalities to ...

Non-quadratic regularization based image formation is a recently proposed framework for feature-enhanced radar imaging. Specific image formation techniques in this framework have so far focused on enhancing one type of feature, such as strong point scatterers, or smooth regions. However, many scenes contain a number of such features. We develop an image formation technique that simultaneously enhances multiple types of features by posing the problem as one of sparse signal representation based on overcomplete dictionaries. Due to the complex-valued nature of the reflectivities in SAR, our new approach is designed to sparsely represent the magnitude of the complex-valued scattered field in terms of multiple features, which turns the image reconstruction problem into a joint optimization problem over the representation of the magnitude and the phase of the underlying field reflectivities. We formulate the mathematical framework needed for this method and propose an iterative solution for the corresponding joint optimization problem. We demonstrate the effectiveness of this approach on various SAR images.

MUVIS is a series of CBIR systems. The first one has been developed in late 90s to support indexing and retrieval in large image databases using visual and semantic features such as color, texture and shape. During recent years, MUVIS has been reformed to become a PC-based framework, which supports indexing, browsing and querying of various multimedia types such as audio, video, audio/video interlaced and several image formats. MUVIS system allows real-time audio and video capturing, encoding by last generation ...

In positron emission tomographic (PET) scanning, transmission measurements for attenuation correction are commonly performed by using external germanium-68 rod sources. Recently, combined PET and computed tomographic (CT) scanners have been developed in which the CT data can be used for both anatomicalmetabolic image formation and attenuation correction of the PET data. The purpose of this study was to evaluate the difference between germanium-and CT-based transmission scanning in terms of their radiation doses by using the same measurement technique and to compare the doses that patients receive during brain, cardiac and whole-body scans. Measurement of absorbed doses to organs was conducted by using a Rando Alderson phantom with thermoluminescent dosimeters. Effective doses were calculated according to the guidelines in the International Commission on Radiation Protection Publication Number 60. Compared with radionuclide doses used in routine 2-[fluorine-18]-fluoro-2-deoxy-D-glucose PET imaging, doses absorbed during germanium-based transmission scans were almost negligible. On the other hand, absorbed doses from CT-based transmission scans were significantly higher, particularly with a whole-body scanning protocol. Effective doses were 8.81 mSv in the high-speed mode and 18.97 mSv in the high-quality mode for whole-body CT-based transmission scans. These measurements revealed that the doses received by a patient during CT-based transmission scanning are more than those received in a typical PET examination. Therefore, the radiation doses represent a limitation to the generalised use of CT-based transmission measurements with current PET/CT scanner systems.

There have been many studies involving the use of hemispherical photographs to indirectly estimate canopy structures and forest light environments. A variety of commercial and free software packages are available for the analysis of hemispherical photographs. The costs of investment might represent an advantage of the free programmes over the commercial, but as yet little has been documented about the differences in their outputs and in the technical applications from a user (ecologist and forester) perspective. The objective of the study was to compare the canopy structure variables (canopy openness and effective plant area index) and solar radiation transmission estimates (direct, diffuse and global solar radiation transmittances) from digital hemispherical photographs taken under two forest canopy conditions (gap and closed canopy) in three different broadleaf forest regions (Chile, Germany, Venezuela) and calculated using four different programmes. The hemispherical photographs were analysed using one commercial (HemiView) and three free programmes (Gap Light Analyzer, hemIMAGE and Winphot). The results obtained revealed that all of the programmes computed similar estimates of both canopy structures and below-canopy solar radiation. Only the results relating to the effective plant area index with an ellipsoidal leaf angle distribution made with HemiView and Winphot deviated significantly. Other user aspects are also discussed, such as costs, image formats, computer system requirements, etc. Zusammenfassung In vielen Studien werden Hemisphärenphotos genutzt um indirekt die Kronenstruktur und die Belichtungsverhältnisse zu schätzen. Verschiedene kommerzielle und kostenfreie Softwarepakete sind zu Analyse von Hemisphärenphotos verfügbar. Es gibt bisher keine umfassende Vergleichsstudie zu Ergebnissen oder technischer Handhabung aus Sicht der Nutzer dieser Programme (Ökologen und Forstwissenschaftler). Das Ziel dieser Studie war der Vergleich der Schätzungen von Kronenstrukturvariablen (Kronenöffnung und effektiver Pflanzenflächenindex) Solartransmission (direkte, diffuse und Global-Strahlung) aus digitalen Hemisphärenphotos berechnet mit vier verschiedenen Programmen (kostenpflichtig: Hemi-View und frei: Gap Light Analyzer, hemIMAGE and Winphot). Die verwendeten Photos stammen aus drei verschiedenen Laubwaldregionen (Chile, Deutschland und Venezuela) und repräsentieren jeweils Verhältnisse unter geschlossenem Kronendach und in Lücken. Die ermittelten Schätzungen für die verschiedenen Strukturvariablen und Einstrahlungsverhältnisse zeigten eine sehr hohe Übereinstimmung. Einzig der effektive Pflanzenflächenindex basierend auf ellipsoider Blattwinkelverteilung unterschied sich signifikant zwischen den Programmen. Weitere für Nutzer interessante Aspekte wie Kosten, Bildformate, Systemvoraussetzungen und mehr wurden verglichen und diskutiert.

Two choices are possible for the refractive index of a linear, homogeneous, isotropic, active, dielectric material. Either of the choices is adequate for obtaining frequency-domain solutions for (i) scattering by slabs, spheres, and other objects of bounded extent; (ii) guided-wave propagation in homogeneously filled, cross-sectionally uniform, straight waveguide sections with perfectly conducting walls; and (iii) image formation due to flat lenses. The correct choice does matter for the half-space problem, but that problem is not realistic.

Travel research consistently shows the importance of word-of-mouth (WOM) information sources in the travel decision-making process. Friends and relatives have been identified as organic image-formation agents, and it has been emphasized that this WOM information is one of the most relied-upon sources of information for destination selection. While there has been recognition of the importance of WOM information sources on consumer behaviour in tourism, little has been performed to understand more specifically how and what behaviour is influenced. This study examined the differing influences of friends and relatives vs. other travellers on the travel choices and behaviours of 412 visitors to the North Queensland Region in Australia. More specifically, the present study compared the following four groups of respondents: those who indicated that they obtained travel information from friends/relatives and other travellers (n = 70); those who obtained information from friends/relatives only (n = 121); those who obtained information from other travellers only (n = 105); and those who obtained information from neither (i.e. no WOM) (n = 116). The results indicated that there were significant differences across the four groups with respect to demographic characteristics, other information sources used, accommodation and transportation used, and travel activities in the destination. However, the groups did not differ in their image of the destination.

Functionality of biological and inorganic systems ranging from nonvolatile computer memories and microelectromechanical systems to electromotor proteins and cellular membranes is ultimately based on the intricate coupling between electrical and mechanical ...

algorithms are widely used in inverse synthetic aperture radar (ISAR) imaging. In the standard RD algorithm, envelope alignment and autofocus are first applied to transform the original data into equivalent turntable target data, and then FFT is used for the image formation. Usually, the migration through resolution cells (MTRCs) due to target rotation is ignored. With the improvement of resolution or the increase of target size, MTRCs cannot be ignored and must be mitigated. For high speed moving targets, the most widely used 'stop-and-go' data model is violated. In this case, the mitigation of MTRCs becomes even more complicated. In the paper, technical issues associated with high resolution ISAR imaging of high speed moving targets are addressed. A preprocessing algorithm is first proposed to convert the non-coherent raw ISAR data into coherent data, then a keystone formatting algorithm developed for the imaging of slow ground moving targets in SAR is applied to mitigate the MTRCs owing to rotational motion, and, finally, a high resolution time -frequency analysis based range -instantaneous Doppler (RID) algorithm is used to produce the focused ISAR image. Numerical examples are provided to illustrate the performance of the proposed approach.

Speckle is a granular noise that inherently exists in all types of coherent imaging systems. The presence of speckle in an image reduces the resolution of the image and the detectability of the target. Many speckle reduction algorithms assume speckle noise is multiplicative. We instead model the speckle according to the exact physical process of coherent image formation. Thus, the

An introduction to the computer image processing and recognition techniques applied for accurately locating an object are presented in this paper. The accurate measurement of three dimensional position requires a camera calibration process as well as the determination of corresponding image points in two images. The accuracy of the three dimensional measurement depends upon the accuracy of the image matching solution.

A self-tuning image restoration filter based on a simplified version of the Jaffe-McGlamery underwater image formation model is presented. Optimal values of the filter parameters are estimated automatically for each individual image by optimizing a quality criterion based on a global contrast measure. The simplified model is ideally suitable for diffuse-light imaging with limited backscatter, but qualitative tests show good performance in a variety of imaging conditions. In addition, quantitative tests with a large number of frames from six real mission videos indicate a substantial performance improvement when restoration is used as a preprocessor for a classifier detecting man-made objects in unconstrained subsea videos.

Software for the processing of electron micrographs in structural biology suffers from incompatibility between different packages, poor definition and choice of conventions, and a lack of coherence in software development. The solution lies in adopting a common philosophy of interaction and conventions between the packages. To understand the choices required to have such common interfaces, I am developing a package called "Bsoft." Its foundations lie in the variety of different image file formats used in electron microscopy-a continually frustrating experience to the user and programmer alike. In Bsoft, this problem is greatly diminished by support for many different formats (including MRC, SPIDER, IMAGIC, SUPRIM, and PIF) and by separating algorithmic issues from image formatspecific issues. In addition, I implemented a generalized functionality for reading the tag-base STAR (self-defining text archiving and retrieval) parameter file format as a mechanism to exchanging parameters between different packages. Bsoft is written in highly portable code (tested on several Unix systems and under VMS) and offers a continually growing range of image processing functionality, such as Fourier transformation, cross-correlation, and interpolation. Finally, prerequisites for software collaboration are explored, which include agreements on information exchange and conventions, and tests to evaluate compatibility between packages.

The physical basis for breast tumor detection with microwave imaging is the contrast in dielectric properties of normal and malignant breast tissues. Confocal microwave imaging involves illuminating the breast with an ultra-wideband pulse from a number of antenna locations, then synthetically focusing reflections from the breast. The detection of malignant tumors is achieved by the coherent addition of returns from these strongly scattering objects. In this paper, we demonstrate the feasibility of detecting and localizing small ( 1 cm) tumors in three dimensions with numerical models of two system configurations involving synthetic cylindrical and planar antenna arrays. Image formation algorithms are developed to enhance tumor responses and reduce early-and late-time clutter. The early-time clutter consists of the incident pulse and reflections from the skin, while the late-time clutter is primarily due to the heterogeneity of breast tissue. Successful detection of 6-mm-diameter spherical tumors is achieved with both planar and cylindrical systems, and similar performance measures are obtained. The influences of the synthetic array size and position relative to the tumor are also explored.

Store image is made up of both tangible and intangible attributes. The knowledge of the composition is of great value for marketing managers and researchers. A store image scale was constructed for fast food restaurants. The scale contains three tangible and three intangible factors. Then a regression analysis and a structural equation analysis were performed to indicate the relative importance of each factor. Results showed that intangible factors are more important than the tangibles for store image formation and for consumer satisfaction. Researchers and marketing managers can use the instrument to have a better understanding of consumer behavior and improve marketing mix.

The present study aims to provide a deeper insight into the factors affecting the formation of tourism destination image. More specifically, it is an attempt to determine the influence that the Internet, as a new information source in intense competition with travel agencies, exerts on the development of the tourist's pre-visit image. With this objective in mind, the paper analyses the ways in which individuals process information proceeding from each of those sources by way of an empirical study based on a multicultural sample of 592 tourists.

This systematic literature review explores the state of the art concerning the theoretical and empirical knowledge of the twice-exceptionality of Intellectual Giftedness and Autism Spectrum Disorders (IG+ASD, in relation to diagnostic and assessment issues. After searching and examining publications in peer-reviewed journals and dissertations, we encountered a variety of methodologies being used. The results show the absence, until now, of theoretical conceptualisations of the phenomenon IG+ASD. Nevertheless, this contribution reveals some converging tendencies concerning both personal characteristics and diagnostic and assessment issues, between publications with and without Systematic Identification Measures (SIM). Some findings, like the 'superior non-verbal abilities', are discussed in relation to (controversial) image formation of IG and IG+ASD. Altogether, the results indicate the need for a further exploration and conceptualisation of the phenomenon IG+ASD. Meanwhile, future research should also address the practical psychological-educational need for both classification-based and needs-based assessment procedures, regarding students with (suspicion of) IG+ASD.

Signal & Image Processing : An International Journal is an Open Access peer-reviewed journal intended for researchers from academia and industry, who are active in the multidisciplinary field of signal & image processing. The scope of the journal covers all theoretical and practical aspects of the Digital Signal Processing & Image processing, from basic research to development of application.

Authors are solicited to contribute to the journal by submitting articles that illustrate research results, projects, surveying works and industrial experiences that describe significant advances in the areas of Signal & Image processing.

11th International Conference on Digital Image Processing and Vision (ICDIPV 2022) is a forum
for presenting new advances and research results in the fields of Digital Image Processing and vision.
The conference will bring together leading researchers, engineers and scientists in the domain of
interest from around the world.
Authors are solicited to contribute to the conference by submitting articles that illustrate research
results, projects, surveying works and industrial experiences that describe significant advances in the
following areas, but are not limited to

Signal & Image Processing : An International Journal is an Open Access peer-reviewed journal intended for researchers from academia and industry, who are active in the multidisciplinary field of signal & image processing. The scope of the journal covers all theoretical and practical aspects of the Digital Signal Processing & Image processing, from basic research to development of application.

Authors are solicited to contribute to the journal by submitting articles that illustrate research results, projects, surveying works and industrial experiences that describe significant advances in the areas of Signal & Image processing.

We present a detailed analysis of image formation in digital Fresnel holography. The mathematical modeling is developed on the basis of Fourier optics, making possible the understanding of the different influences of each of the physical effects invoked in digital holography. Particularly, it is demonstrated that spatial resolution in the reconstructed plane can be written as a convolution product of functions that describe these influences. The analysis leads to a thorough investigation of the effect of the width of the sensor, the surface of pixels, the numerical focusing, and the aberrations of the reference wave, as well as to an explicit formulation of the Shannon theorem for digital holography. Experimental illustrations confirm the proposed theoretical analysis.

ViewDEX (Viewer for Digital Evaluation of X-ray images) is a Java-based DICOM-compatible software tool for observer performance studies that can be used to display medical images with simultaneous registration of the observer's response. The current release, ViewDEX 2.0, is a development of ViewDEX 1.0, which was released in 2007. Both versions are designed to run in a Java environment and do not require any special installation. For example, the program can be located on a memory stick or stand alone hard drive and be run from there. ViewDEX is managed and configured by editing property files, which are plain text files where users, tasks (questions, definitions, etc.) and functionality (WW/WL, PAN, ZOOM, etc.) are defined. ViewDEX reads most common DICOM image formats and the images can be stored in any location connected to the computer. ViewDEX 2.0 is designed so that the user in a simple way can alter if the questions presented to the observers are related to localization or not, enabling e.g. free-response ROC, standard ROC and visual grading studies, as well as combinations of these, to be conducted in a fast and efficient way. The software can also be used for bench marking and for educational purposes. The results from each observer are saved in a log file, which can be exported for further analysis. The software is freely available for non-commercial purposes.

The technique of cepstrum thresholding, which is shown to be an effective, yet simple, way of obtaining a smoothed non parametric spectrum estimate of a stationary signal. The major problem of this method is the choice of the threshold value for variance reduction of spectrum estimates. This paper proposes a new threshold selection method which is based on cross validation schemes such as Leave-One-Out, Leave-Two-Out and Leave-Half-Out. This new methods are easy to describe, simple to implement, and does not impose severe conditions on the unknown spectrum. Numerical results suggest that this new methods are shown to be in agreement with those obtained when the spectrum is fully known.

Signal & Image Processing : An International Journal is an Open Access peer-reviewed journal intended for researchers from academia and industry, who are active in the multidisciplinary field of signal & image processing. The scope of the journal covers all theoretical and practical aspects of the Digital Signal Processing & Image processing, from basic research to development of application.

Authors are solicited to contribute to the journal by submitting articles that illustrate research results, projects, surveying works and industrial experiences that describe significant advances in the areas of Signal & Image processing.

The faint body image embedded into the Turin Shroud has not yet explained by science. We present experimental results of excimer laser irradiation (wavelengths 308 nm and 193 nm) of a raw linen fabric and of a linen cloth, seeking for a possible mechanism of image formation. We achieved a permanent coloration of both linens as a threshold effect of

Forest fire is one of those natural disasters that have been causing huge destruction in terms of loss of vegetation, animals and hence affects the economy. Image segmentation techniques have been applied on satellite images of forest fire to extract fire object and some data mining techniques have been used for predicting the spread of forest fire. This paper proposes a novel approach to isolation of fire region using time-sequenced images, classifying fire images from non-fire images, predicting its movement and estimating the area burnt. Once the images are enhanced, the fire region is segmented out. Feature extraction provides the necessary inputs for classification of images as fire and non-fire images. Linear regression is used to predict the movement of forest fire to facilitate better evacuation strategy. Burnt area is calculated from the difference image. This work is helpful in drafting evacuation strategies quickly by predicting the movement of forest fire and facilitates the kick-off of rehabilitation activities by identifying and assessing the burnt area.

Signal & Image Processing : An International Journal is an Open Access peer-reviewed journal intended for researchers from academia and industry, who are active in the multidisciplinary field of signal & image processing. The scope of the journal covers all theoretical and practical aspects of the Digital Signal Processing & Image processing, from basic research to development of application.

The problem of structure extraction from the image which contains many clustered objects is a challenging one for high level image analysis. When an image contains many clustered objects overlapping of objects can cause for hiding the structure. The existing segmentation techniques for better understanding, not able to the address the constituent parts of the image implicitly. The approaches like multistage segmentation address to some extent, but for each stage a separate structure is extracted, and thus causes for the ambiguity about the structure. The proposed approach called Ant Colony Optimization and Fuzzy logic based technique resolves this problem, and gives the implicit structure, that meets with original structure. The segmentation approach uses the swarm intelligence technique based on the behavior of the ant colonies. The segmentation is the process of separating the non-overlapping regions that constitute an image. The segmentation is important for structured and non-structured image analysis and classification for better understanding

11th International Conference on Digital Image Processing and Vision (ICDIPV 2022) is a forum for presenting new advances and research results in the fields of Digital Image Processing and vision. The conference will bring together leading researchers, engineers and scientists in the domain of interest from around the world.

Authors are solicited to contribute to the conference by submitting articles that illustrate research results, projects, surveying works and industrial experiences that describe significant advances in the following areas, but are not limited to

The determination of Dill parameters of thick resist is very important to improve simulation models of resist exposure and real world processes. A new extraction technique of Dill parameters based on spectroscopic ellipsometry in combination with an advanced resist exposure model is proposed for thick resist analysis. The complex refractive index of the resist is related to the relative concentration of the photoactive compound in the resist in order to describe the vertical distribution of the refractive index and the extinction coefficient. Moreover, Dill parameters are extracted by directly fitting the bleaching curves to the measured ellipsometry data. The new approach was investigated experimentally by spectroscopic ellipsometry measurements on AZ5214E resist with two moderate layer thickness values in order to verify the accuracy of the new method. Dill parameters were extracted by using this new technique and by applying resist samples subjected to different exposure doses. Possible reasons for the variation of Dill parameters depending on resist thickness are explained. Furthermore, advantages, limitations and potential improvements of the model are discussed. Finally, the impact of Dill parameter variation on image formation in the resist is demonstrated by applying the spectroscopic ellipsometer analysis results as input parameters to the lithography simulator Dr.LiTHO.

In this paper, blind image separation is performed, exploiting the property of sparseness to represent images. A new sparse representation called forward difference method is proposed. It is known that most of the independent component analysis (ICA) basis functions, extracted from images are sparse and gives unreliable sparseness measure. In the proposed method, the image mixture is first transformed to sparse images. These images are divided into blocks and for each block the sparseness measure ε0 norm is applied. The block having the most sparseness is considered to determine the separation matrix. The efficiency of the proposed method is compared with other sparse representation functions.

The information explosion makes it easier to ignore information that requires social attention, and news games can make that information stand out. There is also considerable research that shows that people are more likely to remember narrative content. Virtual environments can also increase the amount of information a person can recall. If these elements are blended together, it may help people remember important information. This research aims to provide directional results for researchers interested in combining VR and narrative, enumerating the advantages and limitations of using text or non-text plot prompts in news games. It also provides hints for the use of virtual environments as learning platforms in news games. The research method is to first derive a theoretical derivation, then create a sample of news games, and then compare the experimental data of the sample to prove the theory. The research compares the survey data of a VR game that presents a story in non-text format (Group VR), a game that presents the story in non-text format (Group NVR), a VR game that presents the story in text (Group VRIT), and a game that presents the story in text (Group NVRIT) will be compared and analyzed. This paper describes the experiment. The results of the experiment show that among the four groups, the means that can make subjects remember the most information is a VR news game with a storyline. And there is a positive correlation between subjects' experience and confidence in recognizing memories, and empathy is positively correlated with the correctness of memories. In addition, the effects of "VR," "experience," and "presenting a story from text or video" on the percentage of correct answers differed depending on the type of question.

A difficulty of using confocal microscopy to study Ca 2ϩ sparks is the uncertainty of the linescan position with respect to the source of Ca 2ϩ release. Random placement of the linescan is expected to result in a broad distribution of measured Ca 2ϩ spark amplitudes (a) even if all Ca 2ϩ sparks were generated identically. Thus variations in Ca 2ϩ spark amplitude due to positional differences between confocal linescans and Ca 2ϩ release site are intertwined with variations due to intrinsic differences in Ca 2ϩ release properties. To separate these two sources of variations on the Ca 2ϩ spark amplitude, we determined the effect changes of channel current or channel open time-collectively called the source strength, ␣had on the measured Ca 2ϩ spark amplitude histogram, N(a). This was done by 1) simulating Ca 2ϩ release, Ca 2ϩ and fluo-3 diffusion, and Ca 2ϩ binding reactions; 2) simulation of image formation of the Ca 2ϩ spark by a confocal microscope; and 3) using a novel automatic Ca 2ϩ spark detector. From these results we derived an integral equation relating the probability density function of source strengths, f ␣ (␣), to N(a), which takes into account random positional variations between the source and linescan. In the special, but important, case that the spatial distribution of Ca 2ϩ-bound fluo-3 is Gaussian, we show the following: 1) variations of Ca 2ϩ spark amplitude due to positional or intrinsic differences can be separated, and 2) f ␣ (␣) can, in principle, be calculated from the Ca 2ϩ spark amplitude histogram since N(a) is the sum of shifted hyperbolas, where the magnitudes of the shifts and weights depend on f ␣ (␣). In particular, if all Ca 2ϩ sparks were generated identically, then the plot of 1/N(a) against a will be a straight line. Multiple populations of channels carrying distinct currents are revealed by discontinuities in the 1/N(a) plot. 3) Although the inverse relationship between Ca 2ϩ spark amplitude and decay time might be used to distinguish Ca 2ϩ sparks from different channel populations, noise can render the measured decay times meaningless for small amplitude Ca 2ϩ sparks.