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.
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Book•
03 Oct 1988TL;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
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
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
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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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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TL;DR: The article justifies the efficient use of method noise and explains how its exact use can enhance the result of the algorithm over other efficient methods.
44 citations
TL;DR: A playback setup reproducing an ant walking on sand was used to demonstrate that antlions use sand-borne vibrations to locate their prey, indicating excellent ability to perceive stimulus direction.
Abstract: SUMMARY Substrate-borne vibration for locating mates, predators and prey is
widespread in the animal kingdown. Antlion larvae dig funnel-shaped traps to
catch ants and they are totally immersed in dry sand. We used a playback setup
reproducing an ant walking on sand to clearly demonstrate that antlions use
sand-borne vibrations to locate their prey. Half the tested animals moved
towards the stimulus source. The shoot angle of sand tossing was very close to
the target angle, indicating excellent ability to perceive stimulus direction.
We also discuss orientation mechanisms in sand, a medium with highly unusual
wave propagation properties.
44 citations
TL;DR: The endogenous MAPK deactivator – MAPK phosphatase 1 (MKP‐1) – is a critical negative regulator of the myriad pro‐inflammatory pathways activated by MAPKs in the airway.
Abstract: BACKGROUND AND PURPOSE
Airway remodelling is a consequence of long-term inflammation and MAPKs are key signalling molecules that drive pro-inflammatory pathways. The endogenous MAPK deactivator – MAPK phosphatase 1 (MKP-1) – is a critical negative regulator of the myriad pro-inflammatory pathways activated by MAPKs in the airway.
EXPERIMENTAL APPROACH
Herein we investigated the molecular mechanisms responsible for the upregulation of MKP-1 in airway smooth muscle (ASM) by the corticosteroid dexamethasone and the β2-agonist formoterol, added alone and in combination.
KEY RESULTS
MKP-1 is a corticosteroid-inducible gene whose expression is enhanced by long-acting β2-agonists in an additive manner. Formoterol induced MKP-1 expression via the β2-adrenoceptor and we provide the first direct evidence (utilizing overexpression of PKIα, a highly selective PKA inhibitor) to show that PKA mediates β2-agonist-induced MKP-1 upregulation. Dexamethasone activated MKP-1 transcription in ASM cells via a cis-acting corticosteroid-responsive region located between −1380 and −1266 bp of the MKP-1 promoter. While the 3′-untranslated region of MKP-1 contains adenylate + uridylate elements responsible for regulation at the post-transcriptional level, actinomycin D chase experiments revealed that there was no increase in MKP-1 mRNA stability in the presence of dexamethasone, formoterol, alone or in combination. Rather, there was an additive effect of the asthma therapeutics on MKP-1 transcription.
CONCLUSIONS AND IMPLICATIONS
Taken together, these studies allow us a greater understanding of the molecular basis of MKP-1 regulation by corticosteroids and β2-agonists and this new knowledge may lead to elucidation of optimized corticosteroid-sparing therapies in the future.
44 citations
TL;DR: Quantitative sharpness analysis of ''ideal sample'' micrographs shows that APEX processing can actually produce sharper imagery than is achievable with optimal microscope settings, and is shown to be useful in enhancing and detecting fine detail not otherwise discernible.
Abstract: Loss of resolution due to image blurring is a major concern in electron microscopy. The point spread function describing that blur is generally unknown. We discuss the use of a recently developed fast Fourier transform (FFT)-based direct (noniterative) blind deconvolution procedure, the APEX method, that can process 5123512 images in sec- onds of CPU time on current desktop platforms. The method is predi- cated on a restricted but significant class of shift-invariant blurs, consist- ing of finite convolution products of heavy-tailed Levy probability density functions. Such blurs considerably generalize Gaussian and Lorentzian point spread functions. The method is applied to a variety of original scanning electron microscopy (SEM) micrographs and is shown to be useful in enhancing and detecting fine detail not otherwise discernible. Quantitative sharpness analysis of ''ideal sample'' micrographs shows that APEX processing can actually produce sharper imagery than is achievable with optimal microscope settings. © 2002 Society of Photo-Optical
44 citations
TL;DR: The strategies available to visualize lung, fat, brain, kidney, liver, spleen, vasculature, gastrointestinal tract, and liver tissues of living mice are reviewed using either innate contrast, or commercial injectable or ingestible agents with selective perfusion.
Abstract: X-ray Computed Tomography (CT) is one of the most commonly utilized anatomical imaging modalities for both research and clinical purposes. CT combines high-resolution, three-dimensional data with relatively fast acquisition to provide a solid platform for non-invasive human or specimen imaging. The primary limitation of CT is its inability to distinguish many soft tissues based on native contrast. While bone has high contrast within a CT image due to its material density from calcium phosphate, soft tissue is less dense and many are homogenous in density. This presents a challenge in distinguishing one type of soft tissue from another. A couple exceptions include the lungs as well as fat, both of which have unique densities owing to the presence of air or bulk hydrocarbons, respectively. In order to facilitate X-ray CT imaging of other structures, a range of contrast agents have been developed to selectively identify and visualize the anatomical properties of individual tissues. Most agents incorporate atoms like iodine, gold, or barium because of their ability to absorb X-rays, and thus impart contrast to a given organ system. Here we review the strategies available to visualize lung, fat, brain, kidney, liver, spleen, vasculature, gastrointestinal tract, and liver tissues of living mice using either innate contrast, or commercial injectable or ingestible agents with selective perfusion. Further, we demonstrate how each of these approaches will facilitate the non-invasive, longitudinal, in vivo imaging of pre-clinical disease models at each anatomical site.
44 citations