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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Dissertation•
01 Oct 2003
TL;DR: This thesis presents a stochastic sampling based multiple object tracker, capable of tracking objects from a single camera, in the complex domain of sports games, and focuses on postional performance evaluation.
Abstract: Team games are complicated activities, which involve much interaction between players. Analysing these interactions is of considerable interest; however it is time consuming, error prone, and unreliable to manuallly obtain the positions of the players throughout a game. Automating this process could produce efficient and repeatable results.
Multiple object tracking in large, congested, rapidly changing, and frequently occluded domains (for example a soccer pitch) is a complex problem, particularly given the non-linear nature of each player's movements. This thesis presents a stochastic sampling based multiple object tracker, capable of tracking objects from a single camera, in the complex domain of sports games. Sports players' shapes vary dramatically, presenting challenges to existing techniques. Multi-resolution template based feature descriptors are learned from example players' shape data, providing a mechanism for identifying players' locations in images. Sports scenes are often busy, in the sense that there may be many players close to each other, causing occlusion of one or more players. the use of multiple cameras to resolve these ambiguities is investigated.
Performance evaluation of computer vision systems is an important and often understudied activity. The performance evaluation in this thesis focuses on postional performance evaluation. New metrics and statistisc are presented which provide an important insight into how well a tracking system is performing (and why it may not be).
Analysing the movements of players over time allows a behaviour model of their movements and interactions to be learned. Positional player data is represented and described using density estimation methods. An emergent appraoch to identifying players is presented. Each player's response from a set of learned Gaussian mixture models is used in a graph partitioning scheme. Thsi allows the identification of each player's 'position'. Behaviour and interaction models have potential uses for analysing tactics, identifying good or atypical players, and most powerfully to be incorporated into a multiple obkect tracking system to govern the expected dynamics of the players.
23 citations
TL;DR: The hypothesis that a common neuroadaptive process involving DeltaFosB accumulation in the ventro‐medial caudate underlies the induction but not the expression of behavioral sensitization by different conditions is supported.
Abstract: Both repeated psychostimulants and stress have the ability to promote behavioral sensitization, i.e. enhanced behavioral response to drug challenge. To test whether the behavioral phenotype is also accompanied by similar neuroplastic adaptations, the present study evaluated changes in Fos and FosB/DeltaFosB transcription factors induced in the brain of C57BL/6J mice behaviorally sensitized by repeated amphetamine or repeated restraint stress. Groups of mice received repeated injections of D-amphetamine or saline in group-specific environments. Different groups of mice experienced 2 h of restraint daily for 10 consecutive days. Amphetamine- pre-treated mice, drug-challenged in the environment in which they received drug treatments (Paired), as well as repeatedly stressed mice expressed robust sensitization to the locomotor effects of amphetamine. Both stress- and amphetamine-pre-treated groups showed changes in amphetamine-induced Fos expression; however, none of these changes was shared by the two sensitizing treatments. Instead, accumulation of FosB/DeltaFosB immunoreactivity in the ventro-medial caudate was common to both pre-treatments. These results support the hypothesis that a common neuroadaptive process involving DeltaFosB accumulation in the ventro-medial caudate underlies the induction but not the expression of behavioral sensitization by different conditions.
22 citations
TL;DR: The authors' observations support the concept that strict long-term maintenance of normoglycemia through adequate supply of insulin from endocrine grafts is the ideal prerequisite for cell recovery and restitution of the glucose recognition structures, as well as replication of cells in pancreata with end-stage diabetic patients after high-dose streptozotocin treatment.
Abstract: In the well-established, high-dose streptozotocin diabetic rat model, it is unknown whether normoglycemia after pancreas or islet transplantation may induce the expression of the glucose recognition structures and stimulate the replication of the few surviving pancreatic beta cells. Therefore, the endocrine pancreatic tissue was examined immunocytochemically in streptozotocin-treated major histocompatibility complex congenic Lewis rats at 10 and 100 days after transplantation of whole pancreata or isolated islets implanted under the kidney capsule. In the diabetic state the pancreatic beta cells displayed a weak immunostaining for insulin and glucokinase together with a lack of GLUT2 glucose transporter immunoreactivity in the plasma membrane. Ten days after transplantation, the surviving beta cells had regained their normal immunostaining for insulin and for the glucose recognition structures glucokinase and the A single high dose of streptozotocin causes severe experimental insulin-dependent diabetes mellitus in adult rats due to a selective destruction of the pancreatic beta cells in the islets of Langerhans. At doses between 50 and 60 mg/kg of body weight, only very few beta cells survive in the pancreas (1-3). The diabetic state is irreversible and insulin-dependent, thus representing an experimental animal model for type I diabetes (2). Because of the prevailing hyperglycemia, even the few residual beta cells in the pancreas do not function properly and therefore cannot contribute even to a basal supply of insulin to the organism (4). Pancreatic beta cells can function properly in a diabetic organism apparently only after restitution of normoglycemia (5). GLUT2 glucose transporter. One hundred days after transplantation, both of whole pancreas or isolated islets, the number of surviving beta cells in islets of the pancreata of the recipient animals had increased by two- to threefold. The regenerated beta cells were surrounded by a rim of other endocrine cells. The increase in the number of beta cells was not accompanied by signs of neogenesis from ductal structures in the pancreata. The authors' observations support the concept that strict long-term maintenance of normoglycemia through adequate supply of insulin from endocrine grafts is the ideal prerequisite for beta-cell recovery and restitution of the glucose recognition structures, as well as replication of beta cells in pancreata with end-stage diabetic beta-cell destruction after high-dose streptozotocin treatment.
22 citations
TL;DR: This paper demonstrates that the automatic ISRC is eligible for use in operational VHR satellite-based measurement systems such as those envisaged under the ongoing Global Earth Observation System of Systems (GEOSS) and Global Monitoring for the Environment and Security (GMES) international programs.
Abstract: In the last 20 years, the number of spaceborne very high resolution (VHR) optical imaging sensors and the use of satellite VHR optical images have continued to increase both in terms of quantity and quality of data. This has driven the need for automating quantitative analysis of spaceborne VHR optical imagery. Unfortunately, existing remote sensing image understanding systems (RS-IUSs) score poorly in operational contexts. In recent years, to overcome operational drawbacks of existing RS-IUSs, an original two-stage stratified hierarchical RS-IUS architecture has been proposed by Shackelford and Davis. More recently, an operational automatic pixel-based near-real-time four-band IKONOS-like spectral rule-based decision-tree classifier (ISRC) has been downscaled from an original seven-band Landsat-like SRC (LSRC). The following is true for ISRC: (1) It is suitable for mapping spaceborne VHR optical imagery radiometrically calibrated into top-of-atmosphere or surface reflectance values, and (2) it is eligible for use as the pixel-based preliminary classification first stage of a Shackelford and Davis two-stage stratified hierarchical RS-IUS architecture. Given the ISRC “full degree” of automation, which cannot be surpassed, and ISRC computation time, which is near real time, this paper provides a quantitative assessment of ISRC accuracy and robustness to changes in the input data set consisting of 14 multisource spaceborne images of agricultural landscapes selected across the European Union. The collected experimental results show that, first, in a dichotomous vegetation/nonvegetation classification of four synthesized VHR images at regional scale, ISRC, in comparison with LSRC, provides a vegetation detection accuracy ranging from 76% to 97%, rising to about 99% if pixels featuring a low leaf area index are not considered in the comparison. Second, in the generation of a binary vegetation mask from ten panchromatic-sharpened QuickBird-2 and IKONOS-2 images, the operational performance measurement of ISRC is superior to that of an ordinary normalized difference vegetation index thresholding technique. Finally, the second-stage automatic stratified texture-based separation of low-texture annual cropland or herbaceous range land (land cover class AC/HR) from high-texture forest or woodland (land cover class F/W) is performed in the discrete, finite, and symbolic ISRC map domain in place of the ordinary continuous varying, subsymbolic, and multichannel texture feature domain. To conclude, this paper demonstrates that the automatic ISRC is eligible for use in operational VHR satellite-based measurement systems such as those envisaged under the ongoing Global Earth Observation System of Systems (GEOSS) and Global Monitoring for the Environment and Security (GMES) international programs.
22 citations
TL;DR: Results suggest that S. torgalensis may cope better with harsher temperatures that are characteristic of this species natural environment; S. carolitertii, on the other hand, may be unable to deal with the extreme temperatures faced by the southern species.
Abstract: Comprehension of the mechanisms by which ectotherms, such as fish, respond to thermal stress is paramount for understanding the threats that environmental changes may pose to wild populations. Heat shock proteins are molecular chaperones with an important role in several stress conditions such as high temperatures. In the Iberian Peninsula, particularly in Portugal, freshwater fish of the genus Squalius are subject to daily and seasonal temperature variations. To examine the extent to which different thermal regimes influence the expression patterns of hsp70 and hsc70 transcripts we exposed two species of Squalius (S. torgalensis and S. carolitertii) to different temperatures (20, 25, 30 and 35 °C). At 35 °C, there was a significant increase in the expression of hsp70 and hsc70 in the southern species, S. torgalensis, while the northern species, S. carolitertii, showed no increase in the expression of these genes; however, some individuals of the latter species died when exposed to 35 °C. These results suggest that S. torgalensis may cope better with harsher temperatures that are characteristic of this species natural environment; S. carolitertii, on the other hand, may be unable to deal with the extreme temperatures faced by the southern species.
22 citations