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Formulation and validation of simulated data for the Atmospheric Infrared Sounder (AIRS)

IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 2003年第2期41卷 314-329页

作者： Fishbein, E Farmer, CB Granger, SL Gregorich, DT Gunson, MR Hannon, SE Hofstadter, MD Lee, SY Leroy, SS Strow, LL CALTECH Jet Prop Lab Pasadena CA 91109 USA Univ Maryland Baltimore Cty Dept Phys Baltimore MD 21205 USA

Models for synthesizing radiance measurements by the Atmospheric Infrared Sounder (AIRS) are described. Synthetic radiances have been generated for developing and testing data processing algorithms. The radiances are calculated from geophysical states derived from weather forecasts and climatology using the AIRS rapid transmission algorithm. The data contain horizontal variability at the spatial resolution of AIRS from the surface and cloud fields. This is needed to test retrieval algorithms under partially cloudy conditions. The surface variability is added using vegetation and International Geosphere Biosphere Programme surface type maps, while cloud variability is added randomly. The radiances are spectrally averaged to create High Resolution Infrared Sounder (HIRS) data, and this is compared with actual HIRS2 data on the NOAA 14 satellite. The simulated data underrepresent high-altitude equatorial cirrus clouds and have too much local variability. They agree in the mean to within 1-4 K, and global standard deviation agrees to better than 2 K. Simulated data have been a valuable tool for developing retrieval algorithms and studying error characteristics and will continue to be so after launch.

关键词： algorithm development atmospheric retrieval cloud scene modeling data simulation High Resolution Infrared Sounder (HIRS) satellite remote sensing

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Split and merge codebook design algorithms for image compression

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JOURNAL OF ELECTRONIC IMAGING 2000年第4期9卷 509-520页

作者： Karayiannis, NB Liu, ZY Univ Houston Dept Elect & Comp Engn Houston TX 77204 USA Toshiba Int Corp Houston TX 77041 USA

This paper introduces two new codebook design algorithms for image data compression applications. The proposed algorithms design codebooks by splitting and merging the prototypes of the training vectors, which play the role of code-vectors in the encoding/decoding process. The split-1 (S1) algorithm begins with a codebook containing a single prototype and designs a codebook of the desired size by splitting one prototype at each iteration. The split-1-merge-2 (S1M2) algorithm begins with a codebook of the desired size and improves its quality in an iterative fashion by splitting one prototype and merging two prototypes at each iteration. The proposed algorithms are used to design codebooks for image data compression based on vector quantization. The experimental results indicate that the proposed algorithms are strong competitors to the popular Linde-Buzo-Gray algorithm in terms of their computational requirements and the quality of the designed codebooks. (C) 2000 SPIE and IS&T. [S1017-9909(00)00204-X].

关键词： Prototyping Image compression Quantization Reconstruction algorithms Image quality Image filtering algorithm development Digital imaging Computer programming Optical filters

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Chaotic gray-level image transformation

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JOURNAL OF ELECTRONIC IMAGING 2005年第4期14卷 043001.1-043001.9页

作者： Belkhouche, F Gokcen, I Qidwai, U Tulane Univ Dept Elect Engn & Comp Sci New Orleans LA 70118 USA Gen Elect Global Res Ctr Niskayuna NY USA

We deal with the applications of a class of nonlinear dynamic systems to image transformation and encoding whereby the nonlinear system presents a chaotic or hyperchaotic attractor. Several ways are possible to encode or transform the image using chaos. We develop algorithms for image encoding based on the permutation of the pixel value, position, or both. This approach enables the fast decorrelation of relations among pixels in the initial image in a random-like fashion. We illustrate the use of 1-D, 2-D, and 3-D maps for this purpose. We also use chaotic dynamical systems with a single or two outputs. A discussion of the sensitivity of the algorithms to the keys is followed by the illustration of the algorithms using example images. (c) 2005 SPIE and IS&T.

关键词： Computer programming Complex systems Image compression Dynamical systems Image encryption algorithm development Chaos Diffusion Fractal analysis Nonlinear dynamics

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Long-term evaluation of three satellite ocean color algorithms for identifying harmful algal blooms (Karenia brevis) along the west coast of Florida: A matchup assessment

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REMOTE SENSING OF ENVIRONMENT 2011年第1期115卷 1-18页

作者： Carvalho, Gustavo A. Minnett, Peter J. Banzon, Viva F. Baringer, Warner Heil, Cynthia A. Univ Miami Rosenstiel Sch Marine & Atmospher Sci Div Meteorol & Phys Oceanog Miami FL 33149 USA Univ Miami Rosenstiel Sch Marine & Atmospher Sci NSF NIEHS Oceans & Human Hlth Ctr Miami FL 33149 USA Fish & Wildlife Res Inst Florida Fish & Wildlife Conservat Commiss St Petersburg FL USA

We present a simple algorithm to identify Karenia brevis blooms in the Gulf of Mexico along the west coast of Florida in satellite imagery. It is based on an empirical analysis of collocated matchups of satellite and in situ measurements. The results of this Empirical Approach is compared to those of a Bio-optical Technique - taken from the published literature - and the Operational Method currently implemented by the NOAA Harmful Algal Bloom Forecasting System for K. brevis blooms. These three algorithms are evaluated using a multi-year MODIS data set (from July, 2002 to October, 2006) and a long-term in situ database. Matchup pairs, consisting of remotely-sensed ocean color parameters and near-coincident field measurements of K. brevis concentration, are used to assess the accuracy of the algorithms. Fair evaluation of the algorithms was only possible in the central west Florida shelf (i.e. between 25.75 degrees N and 28.25 degrees N) during the boreal Summer and Fall months (i.e. July to December) due to the availability of valid cloud-free matchups. Even though the predictive values of the three algorithms are similar, the statistical measure of success in red tide identification (defined as cell counts in excess of 1.5 x 10(4) cells L-1) varied considerably (sensitivity - Empirical: 86%;Bio-optical: 77%;Operational: 26%), as did their effectiveness in identifying non-bloom cases (specificity Empirical: 53%;Bio-optical: 65%;Operational: 84%). As the Operational Method had an elevated frequency of false-negative cases (i.e. presented low accuracy in detecting known red tides), and because of the considerable overlap between the optical characteristics of the red tide and non-bloom population, only the other two algorithms underwent a procedure for further inspecting possible detection improvements. Both optimized versions of the Empirical and Bio-optical algorithms performed similarly, being equally specific and sensitive (similar to 70% for both) and showing low

关键词： algorithm development Chlorophyll Detection Gulf of Mexico (west Florida shelf) Harmful algal bloom (HAB) Florida Red Tide (Karenia brevis) Ocean color (MODIS) Satellite remote sensing Water-leaving radiance

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Qualitative analysis of two reconstruction techniques and their application in dentistry

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JOURNAL OF ELECTRONIC IMAGING 2000年第4期9卷 385-393页

作者： Nonato, LG Minghim, R Shimabukuro, MH Univ Sao Paulo Inst Ciencias Matemat & Comp BR-13560970 Sao Carlos SP Brazil UNESP Pres Prudente SP Brazil

Although visualization in the field of dentistry has some of the same requirements as the medicine field, the differences in goal demand specific approaches. This paper reports on the implementation of two fundamentally different approaches to reconstruction of structures from planar cross sections and their application to dentistry data. One of the approaches was an implementation of a distance-based sampling technique, and the other is a new algorithm, based on the Delaunay triangulation. Both were tested using contour data of teeth and the results are compared here in the light of the target applications, which are teaching and training dentistry, as well as simulation of dental procedures and illnesses, Widely mentioned problems encountered in local reconstruction methods such as marching cubes for these cases ate clearly illustrated in this paper, and a very satisfactory alternative is given. (C) 2000 SPIE and IS&T. [S1017-9909(00)01504-X].

关键词： Reconstruction algorithms Dentistry Teeth Visualization 3D modeling Data modeling Visual process modeling algorithm development Computer simulations Medicine

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Evaluation of algorithms for lossless compression of continuous-tone images

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JOURNAL OF ELECTRONIC IMAGING 2002年第1期11卷 75-86页

作者： Savakis, AE Rochester Inst Technol Dept Comp Engn Rochester NY 14623 USA

Lossless image compression algorithms for continuous-tone images have received a great deal of attention in recent years. However, reports on benchmarking their performance have been limited. In this paper, we present a comparative study of the following algorithms: UNIX compress, gzip, LZW, Group 3, Group 4, JBIG, old lossless JPEG, JPEG-LS based on LOCO, CALIC, FELICS, S + P transform, and PNG. The test images consist of two sets of eight bits/pixel continuous-tone images: one set contains nine pictorial images, and another set contains eight document images, obtained from the standard set of CCITT images that were scanned and printed using eight bits/pixel at 200 dpi. In cases where the algorithm under consideration could only be applied to binary data, the bitplanes of the gray scale image were decomposed, with and without Gray encoding, and the compression was applied to individual bit planes. The results show that the best compression is obtained using the CALIC and JPEG-LS algorithms. (C) 2002 SPIE and IST.

关键词： Image compression Computer programming Image processing algorithm development Data modeling Image quality standards Binary data Error analysis Bridges Photonic integrated circuits

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Scheme for detection of low clouds from geostationary weather satellite imagery

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ATMOSPHERIC RESEARCH 2014年 143卷 250-264页

作者： Ishida, Haruma Miura, Kentaro Matsuda, Teruaki Ogawara, Kakuji Goto, Azumi Matsuura, Kuniaki Sato, Yoshiko Nakajima, Takashi Y. Yamaguchi Univ Grad Sch Sci & Engn Ube Yamaguchi 7558611 Japan Japan Weather Assoc Toshima Ku Tokyo 1706055 Japan Tokai Univ Res & Informat Ctr Shibuya Ku Tokyo 1510063 Japan

A simple and practical scheme for low cloud detection at sea based on geostationary weather satellite data is proposed. The scheme consists of several threshold discrimination tests, and time-consuming procedures are eschewed in order to enable near-real-time analysis. This scheme also minimizes the use of data other than from geostationary weather satellites, leading to a convenient low cloud detection procedure without ancillary data. Careful investigation of the radiative properties of low water clouds from radiative transfer simulation and satellite observations enables full utilization of the characteristics of satellite data and realization of the simple scheme. The threshold values, which should possess high generality, for the discrimination tests are obtained from statistical comparisons of Multi-function Transport Satellite-2 data to grid point value data, which allows for extensive data collection and eliminates the localities and anomalies. Verification by comparisons with radiosonde and lidar on satellite suggests that results obtained from the proposed low cloud detection scheme are reasonable. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Satellite remote sensing Low cloud detection algorithm development Geostationary weather satellites

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Class-prioritized compression of multispectral imagery data

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JOURNAL OF ELECTRONIC IMAGING 2002年第2期11卷 246-256页

作者： Saghri, JA Tescher, AG Omran, MGH Calif Polytech State Univ San Luis Obispo Dept Elect Engn San Luis Obispo CA 93407 USA Compress Sci Corp Inc Sunnyvale CA 95085 USA Al Andalus Kuwait Kuwait

A joint classification-compression scheme that provides the user with added capability to prioritize classes of interest in the compression process is proposed. The dual compression system includes a primary unit for conventional coding of a multispectral image set followed by an auxiliary unit to code the resulting error induced on pixel vectors that represent classes of interest. This technique effectively allows classes of interest in the scene to be coded at a relatively higher level of precision than nonessential classes. Prioritized classes are selected from a thematic map or directly specified by their unique spectral signatures. Using the specified spectral signatures of the prioritized classes as end members, a modified linear spectral unmixing procedure is applied to the original data as well as to the decoded data. The resulting two sets of concentration maps, which represent classes prioritized before and after compression, are compared and the differences between them are coded via an auxiliary compression unit and transmitted to the receiver along with a conventionally coded image set. At the receiver, the differences found are blended back into the decoded data for enhanced restoration of the prioritized classes. The utility of this approach is that it works with any multispectral compression scheme. This method has been applied to test the imagery from various platforms including NOAA's AVHRR (1.1 km GSD), and LANDSAT 5 TM (30 m GSD), LANDSAT 5 MSS (79 m GSD). (C) 2002 SPIE and IST.

关键词： Image compression Multispectral imaging Earth observing sensors Landsat algorithm development Associative arrays Image transmission Standards development Sensors Spatial resolution

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Motion-blurred image restoration using modified inverse all-pole filters

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JOURNAL OF ELECTRONIC IMAGING 2004年第2期13卷 257-263页

作者： Likhterov, B Kopeika, NS Ben Gurion Univ Negev Dept Elect Engn IL-84105 Beer Sheva Israel

The restoration of vibration-blurred images using measured motion function is considered. Since the blurring filter is of the finite impulse response type. the inverse one is of the all-pole infinite impulse response type. Direct application of the inverse filter to restore images blurred by vibration is attractive because of reduced computation requirements. Space domain filtering allows high parallelization of the process and reduction of required processor speed. However., a pure inverse filter provides excessive noise amplification and is possibly unstable. The proposed technique is to construct a modified inverse filter with preserved all-pole structure and optimized noise and stability properties. A mathematical concept was developed using z-transform properties. An experiment testing the proposed technique was setup and the results indicate restoration is 60%-80% of that possible with ideal Wiener filtering. However, the reduced computation and high parallelization can facilitate real-time restoration. (C) 2004 SPIE and IST.

关键词： Electronic filtering Image filtering Image restoration Cameras Image quality Modulation transfer functions Solids algorithm development Motion measurement Imaging systems

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Bayesian image reconstruction from Fourier-domain samples using prior edge information

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JOURNAL OF ELECTRONIC IMAGING 2005年第4期14卷 043009.1-043009.1页

作者： Denney, TS Reeves, SJ Auburn Univ Auburn AL 36849 USA

We propose the Bayesian image reconstruction with prior edges ( BIRPE) algorithm for reconstructing an image from Fourier-domain samples with prior edge information from a higher resolution image. A major difference between BIRPE and previous methods is that all edges are detected automatically, and no segmentation of the prior image is required. Also, an edge found in the prior image does not need to be confirmed by the observations;smoothing is reduced across the edge if either the prior image or the observations suggest an edge. Simulations and results on magnetic resonance spectroscopic data are presented that demonstrate the effectiveness of the BIRPE method. (c) 2005 SPIE and IS&T.

关键词： Reconstruction algorithms Image restoration Signal to noise ratio Magnetic resonance imaging Image segmentation algorithm development Image processing algorithms and systems Tissues Edge detection Magnetism

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