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Proceedings Article

Image Processing

01 Jan 1994-
TL;DR: The main focus in MUCKE is on cleaning large scale Web image corpora and on proposing image representations which are closer to the human interpretation of images.
Abstract: MUCKE aims to mine a large volume of images, to structure them conceptually and to use this conceptual structuring in order to improve large-scale image retrieval. The last decade witnessed important progress concerning low-level image representations. However, there are a number problems which need to be solved in order to unleash the full potential of image mining in applications. The central problem with low-level representations is the mismatch between them and the human interpretation of image content. This problem can be instantiated, for instance, by the incapability of existing descriptors to capture spatial relationships between the concepts represented or by their incapability to convey an explanation of why two images are similar in a content-based image retrieval framework. We start by assessing existing local descriptors for image classification and by proposing to use co-occurrence matrices to better capture spatial relationships in images. The main focus in MUCKE is on cleaning large scale Web image corpora and on proposing image representations which are closer to the human interpretation of images. Consequently, we introduce methods which tackle these two problems and compare results to state of the art methods. Note: some aspects of this deliverable are withheld at this time as they are pending review. Please contact the authors for a preview.
Citations
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Book
03 Oct 1988
TL;DR: This chapter discusses two Dimensional Systems and Mathematical Preliminaries and their applications in Image Analysis and Computer Vision, as well as image reconstruction from Projections and image enhancement.
Abstract: Introduction. 1. Two Dimensional Systems and Mathematical Preliminaries. 2. Image Perception. 3. Image Sampling and Quantization. 4. Image Transforms. 5. Image Representation by Stochastic Models. 6. Image Enhancement. 7. Image Filtering and Restoration. 8. Image Analysis and Computer Vision. 9. Image Reconstruction From Projections. 10. Image Data Compression.

8,504 citations

Journal ArticleDOI
TL;DR: The image coding results, calculated from actual file sizes and images reconstructed by the decoding algorithm, are either comparable to or surpass previous results obtained through much more sophisticated and computationally complex methods.
Abstract: Embedded zerotree wavelet (EZW) coding, introduced by Shapiro (see IEEE Trans. Signal Processing, vol.41, no.12, p.3445, 1993), is a very effective and computationally simple technique for image compression. We offer an alternative explanation of the principles of its operation, so that the reasons for its excellent performance can be better understood. These principles are partial ordering by magnitude with a set partitioning sorting algorithm, ordered bit plane transmission, and exploitation of self-similarity across different scales of an image wavelet transform. Moreover, we present a new and different implementation based on set partitioning in hierarchical trees (SPIHT), which provides even better performance than our previously reported extension of EZW that surpassed the performance of the original EZW. The image coding results, calculated from actual file sizes and images reconstructed by the decoding algorithm, are either comparable to or surpass previous results obtained through much more sophisticated and computationally complex methods. In addition, the new coding and decoding procedures are extremely fast, and they can be made even faster, with only small loss in performance, by omitting entropy coding of the bit stream by the arithmetic code.

5,890 citations

Journal ArticleDOI
TL;DR: Eight constructs decellularized hearts by coronary perfusion with detergents, preserved the underlying extracellular matrix, and produced an acellular, perfusable vascular architecture, competent a cellular valves and intact chamber geometry that could generate pump function in a modified working heart preparation.
Abstract: About 3,000 individuals in the United States are awaiting a donor heart; worldwide, 22 million individuals are living with heart failure. A bioartificial heart is a theoretical alternative to transplantation or mechanical left ventricular support. Generating a bioartificial heart requires engineering of cardiac architecture, appropriate cellular constituents and pump function. We decellularized hearts by coronary perfusion with detergents, preserved the underlying extracellular matrix, and produced an acellular, perfusable vascular architecture, competent acellular valves and intact chamber geometry. To mimic cardiac cell composition, we reseeded these constructs with cardiac or endothelial cells. To establish function, we maintained eight constructs for up to 28 d by coronary perfusion in a bioreactor that simulated cardiac physiology. By day 4, we observed macroscopic contractions. By day 8, under physiological load and electrical stimulation, constructs could generate pump function (equivalent to about 2% of adult or 25% of 16-week fetal heart function) in a modified working heart preparation.

2,454 citations

Journal ArticleDOI
01 Sep 1997
TL;DR: This paper examines automated iris recognition as a biometrically based technology for personal identification and verification from the observation that the human iris provides a particularly interesting structure on which to base a technology for noninvasive biometric assessment.
Abstract: This paper examines automated iris recognition as a biometrically based technology for personal identification and verification. The motivation for this endeavor stems from the observation that the human iris provides a particularly interesting structure on which to base a technology for noninvasive biometric assessment. In particular the biomedical literature suggests that irises are as distinct as fingerprints or patterns of retinal blood vessels. Further, since the iris is an overt body, its appearance is amenable to remote examination with the aid of a machine vision system. The body of this paper details issues in the design and operation of such systems. For the sake of illustration, extant systems are described in some amount of detail.

2,046 citations


Cites methods from "Image Processing"

  • ...system makes us of an isotropic bandpass decomposition derived from application of Laplacian of Gaussian filters [25], [29] to the image data....

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  • ...In practice, the filtered image is realized as a Laplacian pyramid [8], [29]....

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Journal ArticleDOI
TL;DR: This paper identifies some promising techniques for image retrieval according to standard principles and examines implementation procedures for each technique and discusses its advantages and disadvantages.

1,910 citations


Cites background or methods from "Image Processing"

  • ...Structural description of chromosome shape (reprinted from [14])....

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  • ...Common invariants include (i) geometric invariants such as cross-ratio, length ratio, distance ratio, angle, area [69], triangle [70], invariants from coplanar points [14]; (ii) algebraic invariants such as determinant, eigenvalues [71], trace [14]; (iii) di<erential invariants such as curvature, torsion and Gaussian curvature....

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  • ...Designers of shape invariants argue that although most of other shape representation techniques are invariant under similarity transformations (rotation, translation and scaling), they depend on viewpoint [14]....

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  • ...The extracting of the convex hull can use both boundary tracing method [14] and morphological methods [11,15]....

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  • ...Assuming the shape boundary has been represented as a shape signature z(i), the rth moment mr and central moment r can be estimated as [14]...

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References
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Journal ArticleDOI
TL;DR: Results show that the fungus actively transports some ions into the wood and controls the distribution of ions at both the bulk wood and cell wall length scales, providing new insights into the movement of ions during decay.
Abstract: The role of ions in the fungal decay process of lignocellulose biomaterials, and more broadly fungal metabolism, has implications for diverse research disciplines ranging from plant pathology and forest ecology, to carbon sequestration. Despite the importance of ions in fungal decay mechanisms, the spatial distribution and quantification of ions in lignocellulosic cell walls and fungal hyphae during decay is not known. Here we employ synchrotron-based X-ray fluorescence microscopy (XFM) to map and quantify physiologically relevant ions, such as K, Ca, Mn, Fe, and Zn, in wood being decayed by the model brown rot fungus Serpula lacrymans. Two-dimensional XFM maps were obtained to study the ion spatial distributions from mm to submicron length scales in wood, fungal hyphae with the dried extracellular matrix (ECM) from the fungus, and Ca oxalate crystals. Three-dimensional ion volume reconstructions were also acquired of wood cell walls and hyphae with ECM. Results show that the fungus actively transports some ions, such as Fe, into the wood and controls the distribution of ions at both the bulk wood and cell wall length scales. These measurements provide new insights into the movement of ions during decay and illustrate how synchrotron-based XFM is uniquely suited study these ions.

37 citations

Journal ArticleDOI
TL;DR: Altered tight junction permeability in cocultures indicates that these cells can work together as an active part of the mucosal barrier.
Abstract: Environmental particulates impact first on airway epithelium, whereas circulating infiltrating cells are recruited through the underlying endothelium. An effective cellular immune response requires coordination between endothelium and epithelium. The authors have developed a bilayer culture model consisting of human bronchial epithelial derived cells (16HBE 14o-) and human umbilical vein endothelial cells (HUVECs) cultured as confluent layers on either side of a porous membrane. Confocal microscopy with epithelial and endothelial-specific antibodies showed segregated cell layers. By scanning and transmission electron microscopy, both cell types are polarized and tight junctions formed at the apical interface between cells. Epithelial cells grown in a bilayer showed significantly increased transepithelial resistance (TER) of 2260 +/- 64 Omega.cm(2) compared to epithelial or endothelial monolayers alone (1400 +/- 70 or 80 +/- 12 Omega.cm(2), respectively). This reflected decreased permeability and was unrelated to cell density or height. Increased TER coincided with increased occludin mRNA and protein in the epithelial cell layer as determined by polymerase chain reaction (PCR) and immunoblotting. Conditioned medium showed that decreased permeability was mediated by soluble endothelial-derived factor(s). This model reflects the in vivo relationship of human airway endothelial cells and epithelial cells. Altered tight junction permeability in cocultures indicates that these cells can work together as an active part of the mucosal barrier.

37 citations

Journal ArticleDOI
TL;DR: By building dictionaries from numerical relativity templates of both, binary black holes mergers and bursts of rotational core collapse, it is shown how machine-learning algorithms based on dictionaries can be also successfully applied for gravitational wave denoising.
Abstract: Gravitational wave astronomy has become a reality after the historical detections accomplished during the first observing run of the two advanced LIGO detectors. In the following years, the number of detections is expected to increase significantly with the full commissioning of the advanced LIGO, advanced Virgo and KAGRA detectors. The development of sophisticated data analysis techniques to improve the opportunities of detection for low signal-to-noise-ratio events is, hence, a most crucial effort. In this paper, we present one such technique, dictionary-learning algorithms, which have been extensively developed in the last few years and successfully applied mostly in the context of image processing. However, to the best of our knowledge, such algorithms have not yet been employed to denoise gravitational wave signals. By building dictionaries from numerical relativity templates of both binary black holes mergers and bursts of rotational core collapse, we show how machine-learning algorithms based on dictionaries can also be successfully applied for gravitational wave denoising. We use a subset of signals from both catalogs, embedded in nonwhite Gaussian noise, to assess our techniques with a large sample of tests and to find the best model parameters. The application of our method to the actual signal GW150914 shows promising results. Dictionary-learning algorithms could be a complementary addition to the gravitational wave data analysis toolkit. They may be used to extract signals from noise and to infer physical parameters if the data are in good enough agreement with the morphology of the dictionary atoms.

37 citations

Journal ArticleDOI
20 Apr 2017-PLOS ONE
TL;DR: The result suggests that Wolbachia does not participate to mitigate oxidative stress in A. japonica, and that on the contrary its presence might still be costly in stressful environments.
Abstract: The oxidative homeostasis is the balance between reactive oxygen species and antioxidant molecules. In addition to be considered as a key factor underlying life-history traits evolution, the oxidative homeostasis has been shown to be involved in many host–symbiont associations. Previous studies suggest an interaction between the bacterial endosymbiont Wolba-chia and the oxidative homeostasis of some insect hosts. This interaction is likely to exert a strong influence on the host evolution, as it has been proposed in the wasp Asobara tabida, whose dependence upon Wolbachia is due to the evolutionary loss of its ability to regulate the oxidative homeostasis in the absence of the symbiont. Although such cases of complete dependence are rare, cases of insects having lost only a part of their autonomy over the control of the oxidative homeostasis might be more common. If so, one can expect that insects having coevolved with Wolbachia will be more sensitive to oxidative stress when cured of their symbionts. We tested this hypothesis by studying the effects of an experimentally-induced oxidative stress on various life-history traits of Asobara japonica, a species closely related to A. tabida. For most of the life-history traits studied, the sensitivity of the wasps to oxidative stress did not correlate with their infection status. The only exception was the parasitic success. However, contrarily to our expectation, the sensitivity to oxidative stress was increased, rather than decreased, when Wolbachia was present. This result suggests that Wolbachia does not participate to mitigate oxidative stress in A. japonica, and that on the contrary its presence might still be costly in stressful environments.

36 citations

Journal ArticleDOI
TL;DR: To characterize the relationship between superparamagnetic ferritin‐bound iron and diffusion tensor scalars in vitro, and validate the results in vivo.
Abstract: Purpose To characterize the relationship between superparamagnetic ferritin-bound iron and diffusion tensor scalars in vitro, and validate the results in vivo. Materials and Methods The in vitro model consisted of a series of 40-mL 1.1% agarose gels doped with ferritin covering and exceeding those concentrations normally found within healthy human gray matter. Additionally, regions of interest were placed in the caudate, putamen, and globus pallidus of 29 healthy volunteer subjects 19–80 years of age. Carr-Purcell-Meiboom-Gill sequence (CPMG) and diffusion tensor imaging (DTI) data were collected at 1.5 Tesla (T) and 3T in vitro, and at 1.5T in vivo. Results In vitro, linear relationships were observed between ferritin-bound iron concentration, R2 (1/T2) and 1/SNR. Eigenvalue repulsion with increasing R2 (decreasing SNR) was reflected in an artifactual increase of fractional anisotropy. In vivo, similar relationships were observed, with mean diffusivity also decreasing linearly with increasing R2. Lambda 3 showed the strongest correlation with R2 both in vitro and in vivo. Conclusion The observation that DTI metrics correlate with ferritin-bound iron is an important consideration in the design and interpretation of studies exploring the diffusion characteristics of gray matter regions, especially in studies focused on adolescence as well as diseases associated with altered brain-iron load such as pantothenate kinase-associated neurodegeneration, Huntington disease and multiple system atrophy. J. Magn. Reson. Imaging 2013;38:1103–1110. © 2013 Wiley Periodicals, Inc.

36 citations