Scarf : Semi-automatic colorization and reliable image fusion
- Authors: Ul-Haq, Anwaar , Gondal, Iqbal , Murshed, Manzur
- Date: 2010
- Type: Text , Conference paper
- Relation: 2010 Digital Image Computing: Techniques and Applications p. 435-440
- Full Text: false
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- Description: Nighttime imagery poses significant challenges to its enhancement due to loss of color information and limitation of single sensor to capture complete visual information at night. To cope with this challenge, multiple sensors are used to capture reliable nighttime imagery which presents additional demands for reliable visual information fusion. In this paper, we present a system, Scarf, which proposes reliable image fusion using advanced feature extraction techniques and a novel semi-automatic colorization based on optimization conformal to human visual system. Subjective and objective quality evaluation proves the effectiveness of proposed system.
Exploiting spatial smoothness to recover undecoded coefficients for transform domain distributed video coding
- Authors: Ali, Mortuza , Murshed, Manzur
- Date: 2013
- Type: Text , Conference paper
- Relation: IEEE International Conference on Image Processing; Melbourne, Australia; 15th-18th September 2013, p. 1782-1786
- Relation: http://purl.org/au-research/grants/arc/DP1095487
- Full Text: false
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- Description: In a transform domain distributed video coding scheme, the correlation between the current encoding unit, e.g. block and slice, and the corresponding side-information is modeled using a virtual channel. This correlation model is then used for rate allocation, quantization, and Wyner-Ziv coding. Since the encoder can only have an estimate of the correlation instead of the exact knowledge of the side-information, the decoder will fail to recover the quantized transformed coeffi- cients with a nonzero probability. In this paper, we propose to integrate a scheme at the decoder to recover the undecoded coefficients using the spatial smoothness property of individual video frames. Simulation results demonstrated that, at different decoding failure probabilities, a transformed coeffi- cient recovery scheme can significantly improve the quality of videos in terms of both PSNR and SSIM.
- Description: In a transform domain distributed video coding scheme, the correlation between the current encoding unit, e.g. block and slice, and the corresponding side-information is modeled using a virtual channel. This correlation model is then used for rate allocation, quantization, and Wyner-Ziv coding. Since the encoder can only have an estimate of the correlation instead of the exact knowledge of the side-information, the decoder will fail to recover the quantized transformed coeffi- cients with a nonzero probability. In this paper, we propose to integrate a scheme at the decoder to recover the undecoded coefficients using the spatial smoothness property of individual video frames. Simulation results demonstrated that, at different decoding failure probabilities, a transformed coeffi- cient recovery scheme can significantly improve the quality of videos in terms of both PSNR and SSIM
A parametric approach to list decoding of Reed-Solomon codes using interpolation
- Authors: Ali, Mortuza , Kiujper, Margreta
- Date: 2011
- Type: Text , Journal article
- Relation: IEEE Transaction on Information Theory Vol. 57, no. 10 (2011), p. 6718-6728
- Full Text: false
- Reviewed:
- Description: Abstract—In this paper, we present a minimal list decoding algorithm for Reed-Solomon (RS) codes. Minimal list decoding for a code refers to list decoding with radius , where is the minimum of the distances between the received word and any codeword in . We consider the problem of determining the value of as well as determining all the codewords at distance . Our approach involves a parametrization of interpolating polynomials of a minimal Gröbner basis . We present two efficient ways to compute . We also show that so-called re-encoding can be used to further reduce the complexity. We then demonstrate how our parametric approach can be solved by a computationally feasible rational curve fitting solution from a recent paper by Wu. Besides, we present an algorithm to compute the minimum multiplicity as well as the optimal values of the parameters associated with this multiplicity, which results in overall savings in both memory and computation
Semantic image retrieval using region based inverted file
- Authors: Zhang, Dengsheng , Islam, Md , Lu, Guojun , Hou, Jin
- Date: 2009
- Type: Text , Journal article
- Relation: Journal of Visual Communication and Image Representation Vol. 24, no. 7 (2009), p.242-249
- Full Text: false
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- Description: Image retrieval has lagged far behind text retrieval despite more than two decades of intensive research effort. Most of the research on image retrieval in the last two decades are on content based image retrieval or image retrieval based on low level features. Recent research in this area focuses on semantic image retrieval using automatic image annotation. Most semantic image retrieval techniques in literature, however, treat an image as a bag of features/words while ignore the structural or spatial information in the image. In this paper, we propose a structural image retrieval method based on automatic image annotation and region based inverted file. In the proposed system, regions in an image are treated the same way as keywords in a structural text document, semantic concepts are learnt from image data to label image regions as keywords and weight is assigned to each keyword according to spatial position and relationship. As the result, images are indexed and retrieved in the same way as structural document retrieval. Specifically, images are broken down to regions which are represented using colour, texture and shape features. Region features are then quantized to create visual dictionaries which are similar to monolingual dictionaries like English or Chinese dictionaries. In the next step, a semantic dictionary similar to a bilingual dictionary like the English–Chinese dictionary is learnt to mapping image regions to semantic concepts. Finally, images are then indexed and retrieved using a novel region based inverted file data structure. Results show the proposed method has significant advantage over the widely used Bayesian annotation models.
Detection and separation of generic-shaped objects by fuzzy clustering
- Authors: Ali, Mohammad , Karmakar, Gour , Dooley, Laurence
- Date: 2010
- Type: Text , Journal article
- Relation: International Journal of Intelligent Computing and Cybernetics Vol. 3, no. 3 (2010 2010), p. 365-390
- Full Text: false
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- Description: Image segmentation involves the separation of mutually exclusive regions/objects of interest (Gonzalez and Woods, 2002), and is integral to the image processing, coding and interpretation domains, with examples of some of the eclectic range of applications including: image analysis, robot vision, automatic car assembly, security surveillance systems, object recognition and medical imaging (Gonzalez and Woods, 2002; Hoppner et al., 1999; Pham and Prince, 1999; Gath and Geva, 1989; Pal and Pal, 1993). As there are potentially a very large number of perceptual objects in an image, with subtle variations between them, this makes generalised object-based segmentation an especially challenging task.
Clustered memetic algorithm for protein structure prediction
- Authors: Islam, M. D. , Chetty, Madhu
- Date: 2010
- Type: Text , Conference paper
- Relation: Evolutionary Computation (CEC), 2010 IEEE Congress
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Data discretization for dynamic Bayesian network based modeling of genetic networks
- Authors: Nguyen, Vinh , Chetty, Madhu , Coppel, Ross , Wangikar, Pramod
- Date: 2012
- Type: Text , Conference paper
- Relation: Neural Information Processing 19th International Conference p. 298-306
- Full Text: false
- Reviewed:
- Description: Dynamic Bayesian networks (DBN) are widely applied in Systems biology for modeling various biological networks, including gene regulatory networks and metabolic networks. The application of DBN models often requires data discretization. Although various discretization techniques exist, currently there is no consensus on which approach is most suitable. Popular discretization strategies within the bioinformatics community, such as interval and quantile discretization, are likely not optimal. In this paper, we propose a novel approach for data discretization for mutual information based learning of DBN. In this approach, the data are discretized so that the mutual information between parent and child nodes is maximized, subject to a suitable penalty put on the complexity of the discretization. A dynamic programming approach is used to find the optimal discretization threshold for each individual variable. Our approach iteratively learns both the network and the discretization scheme until a locally optimal solution is reached. Tests on real genetic networks confirm the effectiveness of the proposed method.
Spherical harmonics and distance transform for image representation and retrieval
- Authors: Sajjanhar, Atul , Lu, Guojun , Zhang, Dengsheng , Hou, Jingyu , Chen, Yi-Ping Phoebe
- Date: 2009
- Type: Text , Conference paper
- Relation: Proceedings of the Intelligent Data Engineering and Automated Learning p. 309-316
- Full Text: false
- Reviewed:
- Description: In this paper, we have proposed a method for 2D image retrieval based on object shapes. The method relies on transforming the 2D images into 3D space based on distance transform. Spherical harmonics are obtained for the 3D data and used as descriptors for the underlying 2D images. The proposed method is compared against two existing methods which use spherical harmonics for shape based retrieval of images. MPEG-7 Still Images Content Set is used for performing experiments; this dataset consists of 3621 still images. Experimental results show that the performance of the proposed descriptors is significantly better than other methods in the same category.
Rhythmic and sustained oscillations in metabolism and gene expression of Cyanothece sp. ATCC 51142 under constant light
- Authors: Gaudana, Sandeep , Krishnakumar, S. , Alagesan, Swathi , Digmurti, Madhuri , Viswanathan, Ganesh , Chetty, Madhu , Wangikar, Pramod
- Date: 2013
- Type: Text , Journal article
- Relation: Frontiers in Microbiology Vol. 4, no. Article 374 (2013), p. 1-11
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- Description: Cyanobacteria, a group of photosynthetic prokaryotes, oscillate between day and night time metabolisms with concomitant oscillations in gene expression in response to light/dark cycles (LD). The oscillations in gene expression have been shown to sustain in constant light (LL) with a free running period of 24 h in a model cyanobacterium Synechococcus elongatus PCC 7942. However, equivalent oscillations in metabolism are not reported under LL in this non-nitrogen fixing cyanobacterium. Here we focus on Cyanothece sp. ATCC 51142, a unicellular, nitrogen-fixing cyanobacterium known to temporally separate the processes of oxygenic photosynthesis and oxygen-sensitive nitrogen fixation. In a recent report, metabolism of Cyanothece 51142 has been shown to oscillate between photosynthetic and respiratory phases under LL with free running periods that are temperature dependent but significantly shorter than the circadian period. Further, the oscillations shift to circadian pattern at moderate cell densities that are concomitant with slower growth rates. Here we take this understanding forward and demonstrate that the ultradian rhythm under LL sustains at much higher cell densities when grown under turbulent regimes that simulate flashing light effect. Our results suggest that the ultradian rhythm in metabolism may be needed to support higher carbon and nitrogen requirements of rapidly growing cells under LL. With a comprehensive Real time PCR based gene expression analysis we account for key regulatory interactions and demonstrate the interplay between clock genes and the genes of key metabolic pathways. Further, we observe that several genes that peak at dusk in Synechococcus peak at dawn in Cyanothece and vice versa. The circadian rhythm of this organism appears to be more robust with peaking of genes in anticipation of the ensuing photosynthetic and respiratory metabolic phases.
Optimal arbitrary shaped pattern-based video coding
- Authors: Paul, Manoranjan , Murshed, Manzur
- Date: 2008
- Type: Text , Conference paper
- Relation: 2008 IEEE 10th Workshop on Multimedia Signal Processing p. 206-211
- Full Text: false
- Reviewed:
- Description: Very low bit-rate video coding algorithms using content-based generated patterns to segment out moving regions at macroblock level have exhibited good potential for improved coding efficiency when embedded into the H.264 standard as extra mode. This content-based pattern generation (CPG) algorithm provides local optimal result as only one pattern can be optimally generated from a given set of moving regions. But, it failed to provide optimal results for multiple patterns from entire sets. Obviously, a global optimal solution for clustering the set and then generation of multiple patterns enhances the performance farther. But a global optimal solution is not achievable due to the non-polynomial nature of the clustering problem. In this paper, we proposed a near optimal content-based pattern generation (OCPG) algorithm which outperforms the existing approach. Coupling OCPG, generating a set of patterns after clustering the macroblocks into several disjoint sets, with direct pattern selection algorithm by allowing all the macroblocks in multiple pattern modes outperforms the existing pattern-based coding while both embedded into the H.264.
Heuristic non parametric collateral missing value imputation : A step towards robust post-genomic knowledge discovery
- Authors: Sehgal, Muhammad Shoaib B , Gondal, Iqbal , Dooley, Laurence , Coppel, Ross
- Date: 2008
- Type: Text , Conference paper
- Relation: Third IAPR International Conference on Pattern Recognition in Bioinformatics (PRIB 2008) Vol. 5625
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- Description: Microarrays are able to measure the patterns of expression of thousands of genes in a genometo give profiles that faciliate much faster analysis of biological process for diagnosis, prognosis and tailored drug discovery. Microarrays, however commonly have missing values, various algorithms have been proposed including Collateral Missing Value Estimation (CMVE), Bayesian Principal Component Analysis (BPCA), Least Square Impute (LSImpute). Local Least Square Impute (LLSImpute) and K-Nearest Neighbour (KNN).
Predictability of moving average rules and nonlinear properties of stock returns: Evidence from the China stock market.
- Authors: Wang, Zhigang , Zeng, Yong , Pan, Heping , Li, Ping
- Date: 2011
- Type: Text , Journal article
- Relation: New mathematics and natural computation Vol. 7, no. 3 (May 2011 2011), p. 267-279
- Full Text: false
- Reviewed:
- Description: This paper investigates t he predictability of moving average rules for the China stock market. We find that buy signals generate higher returns and less volatility, while returns following sell signals are negative and more volatile. Moreover, the bootstrapping results indicate that the asymmetrical patterns of return and volatility between buy and sell signals cannot be explained by four popular linear models of returns, especially the phenomenon of negative sell returns. We then test the nonlinear dynamic process of returns. Although the existing artificial neural network (ANN) model can replicate the negative sell returns, it fails to capture the volatility patterns of buy and sell returns. Furthermore, we introduce the conditional heteroskedasticity structure into the ANN model and find that the revised ANN model cannot only explain the predictability of returns, but can also capture the patterns of buy and sell volatility, which are never achieved by any linear model of returns tested in the related literature. Therefore, we conclude that the moving average trading rules can pick up some of the hidden nonlinear patterns in the dynamic process of stock returns, which may be the reason why they can be used to predict price changes.
Rotation invariant curvelet features for texture image retrieval
- Authors: Islam, Md , Zhang, Dengsheng , Lu, Guojun
- Date: 2009
- Type: Text , Conference paper
- Relation: Proceedings of the 2009 IEEE International Conference on Multimedia and Expo p. 562-565
- Full Text: false
- Reviewed:
- Description: Effective texture feature is an essential component in any content based image retrieval system. In the past, spectral features, like Gabor and wavelet, have shown superior retrieval performance than many other statistical and structural based features. Recent researches on multi-resolution analysis have found that curvelet captures texture properties, like curves, lines, and edges, more accurately than Gabor filters. However, the texture feature extracted using curvelet transform is not rotation invariant. This can degrade its retrieval performance significantly, especially in cases where there are many similar images with different orientations. This paper analyses the curvelet transform and derives a useful approach to extract rotation invariant curvelet features. Experimental results show that the new rotation invariant curvelet feature outperforms the curvelet feature without rotation invariance.
A numerical control algorithm for navigation of an operator-driven snake-like robot with 4WD-4WS segments
- Authors: Percy, Andrew , Spark, Ian
- Date: 2010
- Type: Text , Journal article
- Relation: Robotica Vol. 29, no. 3 (2010), p. 471-482
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- Description: This paper presents a new algorithm for the control of a snake-like robot with passive joints and active wheels. Each segment has four autonomously driven and steered wheels. The algorithm approximates the ideal solution in which all wheels on a segment have the same centre of curvature with wheel speeds, providing cooperative redundancy. Each hitch point joining segments traverses the same path, which is determined by an operator, prescribing the path curvature and front hitch speed. The numerical algorithm developed in this paper is simulation tested against a previously derived analytical solution for a predetermined path. Further simulations are carried out to show the effects of changing curvature and front hitch speed on hitch path, wheel angles and wheel speeds for a one, two and three segment robot.
Simplified theodolite calibration for robot metrology
- Authors: Sultan, Ibrahim , Wager, John
- Date: 2002
- Type: Text , Journal article
- Relation: Advanced Robotics Vol. 16, no. 7 (2002), p. 653-671
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- Description: Theodolites represent a well-established three-dimensional-point-measuring technology. However, when used for robot applications they have to be properly calibrated to fulfil the necessary accuracy requirements. The theodolite calibration methods reported in the literature involve the use of costly sophisticated equipment not easily available to most users. Therefore, a new simplified calibration technique is presented based on the use of a graduated precision bar suspended freely to align with the vertical direction. To develop efficient mathematical models, the theodolites will be regarded as 2R open-ended mechanisms with the end-effector axis directed along the line of sight. The proposed models are then coded in a computer program designed to verify the validity of the technique presented. The simulation results will be presented at the end of the paper.
- Description: 2003000163
Spectrum of Variable-Random trees
- Authors: Liu, Fei , Ting, Kaiming , Yu, Yang , Zhou, Zhi-Hua
- Date: 2008
- Type: Text , Journal article
- Relation: The Journal of Artificial Intelligence Research Vol. 32, no. (2008), p. 355-384
- Full Text: false
- Reviewed:
- Description: In this paper, we show that a continuous spectrum of randomisation exists, in which most existing tree randomisations are only operating around the two ends of the spectrum. That leaves a huge part of the spectrum largely unexplored. We propose a base learner VR-Tree which generates trees with variable-randomness. VR-Trees are able to span from the conventional deterministic trees to the complete-random trees using a probabilistic parameter. Using VR-Trees as the base models, we explore the entire spectrum of randomised ensembles, together with Bagging and Random Subspace. We discover that the two halves of the spectrum have their distinct characteristics; and the understanding of which allows us to propose a new approach in building better decision tree ensembles. We name this approach Coalescence, which coalesces a number of points in the random-half of the spectrum. Coalescence acts as a committee of "experts" to cater for unforeseeable conditions presented in training data. Coalescence is found to perform better than any single operating point in the spectrum, without the need to tune to a specific level of randomness. In our empirical study, Coalescence ranks top among the benchmarking ensemble methods including Random Forests, Random Subspace and C5 Boosting; and only Coalescence is significantly better than Bagging and Max-Diverse Ensemble among all the methods in the comparison. Although Coalescence is not significantly better than Random Forests, we have identified conditions under which one will perform better than the other.
Binary-organoid particle swarm optimisation for inferring genetic networks
- Authors: Chanthaphavong, Santi , Chetty, Madhu
- Date: 2010
- Type: Text , Conference paper
- Relation: Evolutionary Computation (CEC), 2010 IEEE Congress
- Full Text: false
- Reviewed:
- Description: A holistic understanding of genetic interactions is crucial in the analysis of complex biological systems. However, due to the dimensionality problem (less samples and large number of genes) of microarray data, obtaining an optimal gene regulatory network is not only difficult but also computationally expensive. In this paper, a Bayesian model for the genetic interactions using the Minimum Description Length as a scoring metric is proposed. For fast optimisation of the network structure, we propose a novel Swarm Intelligence algorithm called Binary-Organoid Particle Swarm (BORG-Swarm). In BORG-Swarm we introduce the concepts of probability threshold vector and particle drift to update particle positions. Experimental studies are carried out using real-life yeast cell cycle dataset. Results indicate that existing binary swarms fail to converge and suffer from long runtimes. In constrast, BORG-Swarm's fast convergence towards the global optimum becomes apparent from results of extensive simulations.
Issues of grid-cluster retrievals in swarm-based clustering
- Authors: Tan, Swee , Ting, Kaiming , Teng, Shyh
- Date: 2008
- Type: Text , Conference paper
- Relation: Proceedings of the 2008 IEEE World Congress on Computational Intelligence p. 511-518
- Full Text: false
- Reviewed:
- Description: One common approach in swarm-based clustering is to use agents to create a set of clusters on a two-dimensional grid, and then use an existing clustering method to retrieve the clusters on the grid. The second step, which we call grid-cluster retrieval, is an essential step to obtain an explicit partitioning of data. In this study, we highlight the issues in grid-cluster retrievals commonly neglected by researchers, and demonstrate the non-trivial difficulties involved. To tackle the issues, we then evaluate three methods: K-means, hierarchical clustering (Weighted Single-link) and density-based clustering (DBScan). Among the three methods, DBScan is the only method which has not been previously used for grid-cluster retrievals, yet it is shown to be the most suitable method in terms of effectiveness and efficiency.
Density estimation based on mass
- Authors: Ting, Kaiming , Washio, Takashi , Wells, Jonathan , Liu, Fei
- Date: 2011
- Type: Text , Conference paper
- Relation: 11th IEEE International Conference on Data Mining (ICDM 2011) p. 715-724
- Full Text: false
- Reviewed:
- Description: Density estimation is the ubiquitous base modelling mechanism employed for many tasks such as clustering, classification, anomaly detection and information retrieval. Commonly used density estimation methods such as kernel density estimator and k-nearest neighbour density estimator have high time and space complexities which render them inapplicable in problems with large data size and even a moderate number of dimensions. This weakness sets the fundamental limit in existing algorithms for all these tasks. We propose the first density estimation method which stretches this fundamental limit to an extent that dealing with millions of data can now be done easily and quickly. We analyze the error of the new estimation (from the true density) using a bias-variance analysis. We then perform an empirical evaluation of the proposed method by replacing existing density estimators with the new one in two current density-based algorithms, namely, DBSCAN and LOF. The results show that the new density estimation method significantly improves the runtime of DBSCAN and LOF, while maintaining or improving their task-specific performances in clustering and anomaly detection, respectively. The new method empowers these algorithms, currently limited to small data size only, to process very large databases - setting a new benchmark for what density-based algorithms can achieve.
Unitary anomaly detection for ubiquitous safety in machine health monitoring
- Authors: Amar, Muhammad , Gondal, Iqbal , Wilson, Campbell
- Date: 2012
- Type: Text , Conference paper
- Relation: 19th International Conference on Neural Information Processing (INCONIP) p. 361-368
- Full Text: false
- Reviewed:
- Description: Safety has always been of vital concern in both industrial and home applications. Ensuring safety often requires certain quantifications regarding the inclusive behavior of the system under observation in order to determine deviations from normal behavior. In machine health monitoring, the vibration signal is of great importance for such measurements because it includes abundant information from several machine parts and surroundings that can influence machine behavior. This paper proposes a unitary anomaly detection technique (UAD) that, upon observation of abnormal behavior in the vibration signal, can trigger an alarm with an adjustable threshold in order to meet different safety requirements. The normalized amplitude of spectral contents of the quasi stationary time vibration signal are divided into frequency bins, and the summed amplitudes frequencies over bin are used as features. From a training set consisting of normal vibration signals, Gaussian distribution models are obtained for each feature, which are then used for anomaly detection.