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international conference on 3d imaging, modeling, Processing, Visualization and Transmission (3dIMPVT)

作者： L. Lucchese G. doretto G.M. Cortelazzo Department of Electronics and Informatics University of Padova Padova Italy

Video-rate registered range and intensity data are at reach of current sensor technology. This wealth of data can be profitably exploited in order to estimate rigid motion parameters as the approaches to 3-d motion estimation, based on the optical flow of both types of data, indicate. This work introduces an alternative for 3-d motion estimation based on the Fourier transform of the 3-d intensity function implicitly described by the registered time-sequences of range and intensity data. The proposed procedure can lead to an unsupervised method for 3-d rigid motion estimation. This method has several advantages related to the fact that it uses the total available information and not sets of features. With respect to memory occupancy the use of a time-sequence of a 3-d intensity function represents a considerable data reduction with respect to a pair of time-sequences of 2-d functions. The proposed technique, which extends to the 3-d case previous frequency domain estimation algorithms developed for the planar case, retain their robustness.

关键词： Frequency domain analysis Frequency estimation Motion estimation Fourier transforms Parameter estimation Robustness Surface texture Solids Informatics Optical sensors

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Prediction of observed image spectra using synthetic image generation models

Prediction of observed image spectra using synthetic image g...

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3rd Spectrometry conference

作者： Schott, JR Kuo, d Brown, S Raqueno, R Rochester Institute of Technology (United States)

ISBN: (纸本)0819425400

Most spectrometric image analysis algorithms either require or can be augmented by estimates of target/background spectral signatures. The prediction of these spectra is complicated by the complex interplay of the target's spectra, background spectra, energy matter interaction effects, atmospheric effects and sensor response, and noise effects. Signatures can be further confused in the thermal infrared by the temperature and temperature variation of targets and backgrounds. Finally, in nearly all cases, the image signature is the result of spatial mixing (possibly nonlinearly) of target and background spectra. This paper addresses the potential for using synthetic image generation modeling tools to help in the prediction and understanding of hyperspectral signatures. The dIRSIG model is discussed in terms of how it deals spectrally with target/background interactions (i.e., bi-directional reflectance effects and thermal radiation loading), atmospheric propagation (MOdTRAN-based atmospheric spectral transmission, path radiance, and downwelled radiance exhibiting both zenith and azimuthal variation) and sensor spectral, geometric MTF and noise effects. The dIRSIG model, enables the estimation of mixed pixel ''image'' spectra as they would be observed by an actual system imaging a complex 3-dimensional scene. This paper emphasizes recent advances in dIRSIG that provide improved modeling of the spectra of transparent objects. Examples showing the effect of multilayered tree canopies, including leaf spectral transmission and self-shadowing, are presented. In addition, the case of estimating spectral signatures of complex gaseous plumes (e.g., clouds, factory stack plumes, cooling towers) will be treated. This treatment will emphasize the effects of temperature, absorption, and self-emission of the plume and the background on plume/background interactions and on the spectral signatures in the thermal infrared spectral region. Both image and spectral examples emphasizing t

关键词： imaging spectrometry hyperspectral imaging synthetic image generation dIRSIG

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Registration of 3-d partial surface models using luminance and depth information

Registration of 3-D partial surface models using luminance a...

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international conference on 3d imaging, modeling, Processing, Visualization and Transmission (3dIMPVT)

作者： S. Weik Institut für Theoretische Nachrichtentechnik und Informationsverarbeitung Universität Hannover Germany

Textured surface models of three-dimensional objects are gaining importance in computer graphics applications. These models often have to be merged from several overlapping partial models which have to be registered (i.e. the relative transformation between the partial models has to be determined) prior to the merging process. In this paper a method is presented that makes use of both camera-based depth information (e.g. from stereo) and the luminance image. The luminance information is exploited to determine corresponding point sets on the partial surfaces using an optical flow approach. Quaternions are then employed to determine the transformation between the partial models which minimizes the sum of the 3-d Euclidian distances between the corresponding point sets. In order to find corresponding points on the partial surfaces luminance information is linearized. The procedure is iterated until convergence is reached. In contrast to only using depth information, employing luminance speeds up convergence and reduces remaining degrees of freedom (e.g. when registering sphere-like shapes).

关键词： Surface texture Surface reconstruction Cameras Image reconstruction Optical sensors Stereo image processing Computer graphics Application software Lapping Merging

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Lip motion modeling and speech driven estimation

Lip motion modeling and speech driven estimation

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1997 IEEE international conference on Acoustics, Speech, and Signal Processing (ICASSP 97)

作者： Lavagetto, F Lepsoy, S Braccini, C Curinga, S Univ of Genova Genova Italy

ISBN: (纸本)0818679204

recent advances in joint acoustical/visual analysis for model-based lip motion synthesis is presented. The 2d lip motion field is modeled as a linear combination of a low dimensional motion basis computed through Principal Component Analysis (PCA). The vector of PCA coefficients is expressed as a function of a limited set of articulatory parameters which describe the external appearance of the mouth. The acoustical processing estimates these articulatory parameters from the direct analysis of the speech waveform based on a neural processing stage, i.e. through a bank of Time delay Neural Networks. The achieved results have been subjectively evaluated by visualizing the estimated motion on a wire-frame mouth template presented in synchronization with speech. The experiments carried out so far deal with single-speaker trained TdNNs and with single-speaker PCA, but suitable algorithms for generalizing the techniques are currently under investigation.

关键词： Speech processing

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Segmentation of range images into planar regions

Segmentation of range images into planar regions

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international conference on 3d imaging, modeling, Processing, Visualization and Transmission (3dIMPVT)

作者： P. Checchin L. Trassoudaine J. Alizon Laboratoire des Sciences et Matériaux pour l'Electronique et d'Automatique (LASMEA) Université Blaise Pascal de Clermont-Ferrand Aubiere France

This paper presents a hybrid approach to the segmentation of range images into planar regions. The term hybrid refers to a combination of edge- and region-based considerations. A reliable computational procedure which takes the range image discontinuities into account is presented for computing the pixel's normal. The segmentation algorithm consists of two parts. In the first one, the pixels are aggregated according to local properties derived from the input data and are represented by a region adjacency graph (RAG). At this stage, the image is still over-segmented. In the second part, the segmentation is refined thanks to the construction of an irregular pyramid. The base of the pyramid is the RAG previously extracted. The over-segmented regions are merged using a surface-based description. This algorithm has been evaluated on 80 real images acquired by two different range sensors using the methodology proposed in (Hoover et al., 1996). Experimental results are presented and compared to others obtained by four research groups.

关键词： Image segmentation data mining Image edge detection Pixel Partitioning algorithms Image sensors Layout Image analysis Performance analysis Surface fitting

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deep hydraulic fracture imaging: recent advances in tiltmeter technologies

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international Journal of Rock Mechanics and Mining Sciences 1997年第3-4期34卷 47.e1-47.e9页

作者： Castillo, d. Hunter, S. Harben, P. Wright, C. Conant, R. davis, E. Earth Science Division Lawrence Livermore National Laboratory LivermoreCA94551 United States Pinnacle Technologies Inc. 600 Townsend Street Suite 160W San FranciscoCA94103 United States

Significant advancements in tiltmeter technologies has improved our ability to map the geometry of hydraulic fractures at great depth. This department of Energy sponsored effort with widespread industry collaboration has extended the capability of near-surface tiltmeters to image details of the hydraulic fracture process at depths approaching 10,000 feet. Improvements in the analog-digital circuitry, the data-logger, and the remote mechanical leveling device has enabled us to install tiltmeters in relatively deep holes where the degradation affects due to the natural-cultural noise sources on the tilt-signal are minimized. Another benefit of utilizing this technology in the oil and gas industry is that it provides valuable information on the geometry of these hydraulic fractures, which is important for production field design. modeling tilmeter data with algorithms that take into account details of the fracture growth process and the local geology are currently being developed, especially since recent results indicate that signal strength from deeper hydraulic fractures may be stronger than previous models had suggested. © 1997

关键词： Fracture

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Three-dimensional region-based adaptive image processing techniques for volume visualization applications

Three-dimensional region-based adaptive image processing tec...

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conference on Image display

作者： dedeusLopes, R Zuffo, MK Rangayyan, RM UNIV SAO PAULO ESCOLA POLITECNLAB SISTEMAS INTEGRAVEISBR-05508900 SAO PAULOBRAZIL

ISBN: (纸本)0819420824

recent advances in three-dimensional (3d) imaging techniques have expanded the scope of applications of volume visualization to many areas such as medical imaging, scientific visualization, robotic vision, and virtual reality. Advanced image filtering, enhancement, and analysis techniques are being developed in parallel in the field of digital image processing. Although the fields cited have many aspects in common, it appears that many of the latest developments in image processing are not being applied to the fullest extent possible in visualization. It is common to encounter the use of rather simple and elementary image pre- processing operations being used in visualization and 3d imaging applications. The purpose of this paper is to present an overview of selected topics from recent developments in adaptive image processing and demonstrate or suggest their applications in volume visualization. The techniques include adaptive noise removal; improvement of contrast and visibility of objects; space-variant deblurring and restoration; segmentation-based lossless coding for data compression; and perception-based measures for analysis, enhancement, and rendering. The techniques share the common base of identification of adaptive regions by region growing, which lends them a perceptual basis related to the human visual system. Preliminary results obtained with some of the techniques implemented so far are used to illustrate the concepts involved, and to indicate potential performance capabilities of the methods.

关键词： volume visualization medical imaging three-dimensional image processing image enhancement image coding image compression adaptive image processing region-based image processing noise removal contrast enhancement

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Thermal characterization of defects in aircraft structures via spatially controlled heat application

Thermal characterization of defects in aircraft structures v...

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Thermosense XVIII: An international conference on Thermal Sensing and imaging diagnostic Applications

作者： Cramer, K.Elliott Winfree, William P. NASA Langley Research Cent. Hampton VA USA

ISBN: (纸本)0819421472

recent advances in thermal imaging technology have spawned a number of new thermal NdE techniques that provide quantitative information about flaws in aircraft structures. Thermography has a number of advantages as an inspection technique. It is a totally noncontacting, nondestructive, imaging technology capable of inspecting a large area in a matter of a few seconds. The development of fast, inexpensive image processors have aided in the attractiveness of thermography as an NdE technique. These image processors have increased the signal to noise ratio of thermography and facilitated significant advances in post- processing. The resulting digital images enable archival records for comparison with later inspections thus providing a means of monitoring the evolution of damage in a particular structure. The National Aeronautics and Space Administrations's Langley Research Center has developed a thermal NdE technique designed to image a number of potential flaws in aircraft structures. The technique involves injecting a small, spatially controlled heat flux into the outer surface of an aircraft. Images of fatigue cracking, bond integrity and material loss due to corrosion are generated from measurements of the induced surface temperature variations. This paper presents a discussion of the development of the thermal imaging system as well as the techniques used to analyze the resulting thermal images. Spatial tailoring of the heat coupled with the analysis techniques represent a significant improvement in the detectability of flaws over conventional thermal imaging. Results of laboratory experiments on fabricated crack, disbond and material loss samples are presented to demonstrate the capabilities of the technique. An integral part of the development of this technology is the use of analytic and computational modeling. The experimental results are compared with these models to demonstrate the utility of such an approach.

关键词： Thermal imaging

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USE OF LOWTRAN dERIVEd ATMOSPHERIC PARAMETERS IN SYNTHETIC IMAGE GENERATION MOdELS

USE OF LOWTRAN DERIVED ATMOSPHERIC PARAMETERS IN SYNTHETIC I...

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conference on recent advances in Sensors, Radiometric Calibration, and Processing of Remotely Sensed data

作者： SALVAGGIO, C SIRIANNI, Jd SCHOTT, JR ROCHESTER INST TECHNOL CTR IMAGING SCIDIGITAL IMAGING & REMOTE SENSING LABROCHESTERNY 14623

ISBN: (纸本)0819411744

The digital imaging and Remote Sensing laboratory's Image Generation model combines computer aided design, ray tracing techniques, radiometric principles, and thermodynamic models to create synthetic imagery. The model emphasizes rigorous radiometric solutions that account for spectral reflectance effects, angular emissivities, atmospheric transmission and upwelled and downwelled sky radiance. This paper describes enhancements to the radiometric portion of the code that permits inclusion of variations with azimuth of downwelling sky radiance, solution of the radiometric propagation models using specific radiosonde data including adjustments for the time of day, and the incorporation of background effects from objects adjacent to the target. Simulated scenes are presented that show how these enhancements produce imagery that more closely match observed phenomena. In particular, the importance of properly modeled sky radiance is shown both for low altitude oblique imagery where the sky is directly observed and for near nadir imagery where reflected sky radiance is important.

关键词： Atmospheric modeling Sensors data modeling Ray tracing Reflectivity Atmospheric propagation Atmospheric sensing Solid modeling digital imaging databases

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VISUAL SIMULATION OF digital ATMOSPHERIC dATA

VISUAL SIMULATION OF DIGITAL ATMOSPHERIC DATA

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conference on recent advances in Sensors, Radiometric Calibration, and Processing of Remotely Sensed data

作者： MONTAG, BC SW RES INST SAN ANTONIOTX 78238

ISBN: (纸本)0819411744

Sources of remotely sensed atmospheric data have expanded rapidly within the last several years, including ground-based doppler weather radars and several satellite-based, earth- observing systems that sense and record large-scale weather conditions. Although these systems are capable of producing voluminous amounts of data, tools for visualizing, analyzing, and applying the data for operational uses requiring 4d display have not kept up. This paper presents a discussion of a software system known as WEST (Weather Environment Simulation Technology). WEST was developed through internal funding at Southwest Research Institute, for the visualization and simulator integration of very large atmospheric data sets containing fine-grained weather features. The approach implemented within WEST allows the user to visually observe, 'fly through', and interact with recorded atmospheric data at real-time speeds using commercial off-the-shelf hardware. This new capability is designed to benefit such diverse applications as flight training, weather analysis, systems design, and mission planning.

关键词： Visualization Computer simulations data modeling Atmospheric modeling databases Visual process modeling Clouds Image processing Visual analytics Atmospheric sensing

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