This paper presents an approach to image understanding on the aspect of unsupervised scene segmentation. With the goal of image understanding in mind, we consider 'unsupervised scene segmentation' a task of di...
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This paper presents an approach to image understanding on the aspect of unsupervised scene segmentation. With the goal of image understanding in mind, we consider 'unsupervised scene segmentation' a task of dividing a given image into semantically meaningful regions without using annotation or other human-labeled information. We seek to investigate how well an algorithm can achieve at partitioning an image with limited human-involved learning procedures. Specifically, we are interested in developing an unsupervised segmentation algorithm that only relies on the contextual prior learned from a set of images. Our algorithm incorporates a small set of images that are similar to the input image in their scene structures. We use the sparse coding technique to analyze the appearance of this set of images;the effectiveness of sparse coding allows us to derive a priori the context of the scene from the set of images. Gaussian mixture models can then be constructed for different parts of the input image based on the sparse-coding contextual prior, and can be combined into an Markov-random-field-based segmentation process. The experimental results show that our unsupervised segmentation algorithm is able to partition an image into semantic regions, such as buildings, roads, trees, and skies, without using human-annotated information. The semantic regions generated by our algorithm can be useful, as pre-processed inputs for subsequent classification-based labeling algorithms, in achieving automatic scene annotation and scene parsing.
The sparse prior has been widely adopted to establish data models for numerous applications. In this context, most of them are based on one of three foundational paradigms: the conventional sparse representation, the ...
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In this paper, first, we carried out dictionary learning to process the sparse coding in advance, and then, we added six types of noise for 3D CG images. Next, we processed noise removal based on sparse coding theory ...
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ISBN:
(纸本)9781665418751
In this paper, first, we carried out dictionary learning to process the sparse coding in advance, and then, we added six types of noise for 3D CG images. Next, we processed noise removal based on sparse coding theory and dictionary learning. Before and after image processing, we discussed improvement of image quality evaluation value eventually by measuring PSNR.
In this paper, we present an algorithm to super-resolve the acquired frames in a hyperspectral video using sparse coding and applying a Beta process. For this purpose, we apply Beta process in Bayesian dictionary lear...
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ISBN:
(纸本)9783030904364;9783030904357
In this paper, we present an algorithm to super-resolve the acquired frames in a hyperspectral video using sparse coding and applying a Beta process. For this purpose, we apply Beta process in Bayesian dictionary learning and we will generate a sparse coding regarding the hyperspectral video super-resolution. The spatial super-resolution was followed by a spectral video restoration process using two different dictionaries which one of them is trained for spatial super-resolution and the other one is trained for the spectral restoration. We have experimented our proposed strategy over a large public hyperspectral video database including a 31-frame hyperspectral video (each frame has 33 bands from 400 nm to 720 nm wavelength with a 10 nm step) and compared the outcome with other state of the art methodologies. The proposed method is evaluated on RMSE, PSNR, SSIM and VSNR metrics. The comparison results prove that our proposed method outperforms other state of the art techniques.
Similarity quantification is an important field of study in electroencephalogram (EEG)-based brain activity detection, in which the goal is to compute interdependence between certain cortical areas from inter-hemisphe...
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Similarity quantification is an important field of study in electroencephalogram (EEG)-based brain activity detection, in which the goal is to compute interdependence between certain cortical areas from inter-hemispheric or intra-hemispheric channel pairs. This study aims to propose a new interdependence EEG feature, namely Dynamic frequency warpping(DFW) based on dynamic analysis of frequency fluctuations as a hybrid feature extraction step. A new EEG classifier based on sparse coding has been developed for Attention Deficit Hyperactivity Disorder (ADHD) detection. It has been tested using EEG recordings of 14 ADHD children and 19 healthy controls during resting state and a time-reproduction task. The capability of the proposed method with an accuracy rate of 99.17% has been shown. Use of the DFW extracted from frontal channel pairs or beta frequency band not only improves the performance but also reduces the computational complexity due to the need to a subgroup of channels or a subband.
This research takes an application-specific approach to investigate, extend and implement the state of the art in the fields of both visual information retrieval and machine learning, bridging the gap between theoreti...
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This research takes an application-specific approach to investigate, extend and implement the state of the art in the fields of both visual information retrieval and machine learning, bridging the gap between theoretical models and real world applications. During an image-guided neurosurgery, path planning remains the foremost and hence the most important step to perform an operation and ensures the maximum resection of an intended target and minimum sacrifice of health tissues. In this investigation, the technique of content-based image retrieval (CBIR) coupled with machine learning algorithms are exploited in designing a computer aided path planning system (CAP) to assist junior doctors in planning surgical paths while sustaining the highest precision. Specifically, after evaluation of approaches of sparse coding and K-means in constructing a codebook, the model of sparse codes of 3D SIFT has been furthered and thereafter employed for retrieving, The novelty of this work lies in the fact that not only the existing algorithms for 2D images have been successfully extended into 3D space, leading to promising results, but also the application of CBIR that is mainly in a research realm, to a clinical sector can be achieved by the integration with machine learning techniques. Comparison with the other four popular existing methods is also conducted, which demonstrates that with the implementation of sparse coding, all methods give better retrieval results than without while constituting the codebook, implying the significant contribution of machine learning techniques. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.
Recently, sparse coding has become popular for image classification. However, images are often captured under different conditions such as varied poses, scales and different camera parameters. This means local feature...
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Recently, sparse coding has become popular for image classification. However, images are often captured under different conditions such as varied poses, scales and different camera parameters. This means local features may not be discriminative enough to cope with these variations. To solve this problem, affine transformation along with sparse coding is proposed. Although proven effective, the affine sparse coding has no constraints on the tilt and orientations as well as the encoding parameter consistency of the transformed local features. To solve these problems, we propose a Laplacian affine sparse coding algorithm which combines the tilt and orientations of affine local features as well as the dependency among local features. We add tilt and orientation smooth constraints into the objective function of sparse coding. Besides, a Laplacian regularization term is also used to characterize the encoding parameter similarity. Experimental results on several public datasets demonstrate the effectiveness of the proposed method. (C) 2013 Elsevier Inc. All rights reserved.
Case-based intelligent fault diagnosis has had some notable successes in recent years. However, compared with parameter-based methods, they pay less attention to automatic and powerful feature extraction. Meanwhile, m...
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Case-based intelligent fault diagnosis has had some notable successes in recent years. However, compared with parameter-based methods, they pay less attention to automatic and powerful feature extraction. Meanwhile, most approaches use k-nearest neighbor (KNN) algorithms or related variants, which fail in adaptive nearest neighbor location. To deal with these shortcomings, an algorithm called adaptive nearest neighbor reconstruction (ANNR) is proposed, which can take advantage of both parameter- and case-based diagnosis methods. Firstly, ANNR offers sparse and robust feature extraction by designed deep contractive sparse filtering (DCSF), which fuses a local contractive term to learn robust feature manifolds. Secondly, to locate the nearest neighbors for diverse testing samples adaptively, a case-based reconstruction algorithm is developed to obtain correlation vectors between training and testing samples. Finally, according to correlation vector of each testing sample, its optimized nearest neighbors are located, enabling precise feature classification. Extensive experiments were conducted on two roller bearing vibration signal datasets and verified its effectiveness.
Sensory inputs conveying information about the environment are often noisy and incomplete, yet the brain can achieve remarkable consistency in recognizing objects. Presumably, transforming the varying input patterns i...
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Sensory inputs conveying information about the environment are often noisy and incomplete, yet the brain can achieve remarkable consistency in recognizing objects. Presumably, transforming the varying input patterns into invariant object representations is pivotal for this cognitive robustness. In the classic hierarchical representation framework, early stages of sensory processing utilize independent components of environmental stimuli to ensure efficient information transmission. Representations in subsequent stages are based on increasingly complex receptive fields along a hierarchical network. This framework accurately captures the input structures;however, it is challenging to achieve invariance in representing different appearances of objects. Here we assess theoretical and experimental inconsistencies of the current framework. In its place, we propose that individual neurons encode objects by following the principle of maximal dependence capturing (MDC), which compels each neuron to capture the structural components that contain maximal information about specific objects. We implement the proposition in a computational framework incorporating dimension expansion and sparse coding, which achieves consistent representations of object identities under occlusion, corruption, or high noise conditions. The framework neither requires learning the corrupted forms nor comprises deep network layers. Moreover, it explains various receptive field properties of neurons. Thus, MDC provides a unifying principle for sensory processing.
This paper studies ill-posed tomographic imaging problems where the image is sparsely represented by a non-negative linear combination of Gaussians. Our main contribution is to develop a scheme for directly recovering...
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This paper studies ill-posed tomographic imaging problems where the image is sparsely represented by a non-negative linear combination of Gaussians. Our main contribution is to develop a scheme for directly recovering the Gaussian mixture representation of an image from tomographic data, which here is modeled as noisy samples of the parallel-beam ray transform. An important aspect of this non-convex reconstruction problem is the choice of initial guess. We propose an initialization procedure that is based on a filtered back projection type of operator tailored for the Gaussian dictionary. This operator can be evaluated efficiently using an approximation of the Riesz-potential of an anisotropic Gaussian which is based on an exact closed form expression for the Riesz-potential of an isotropic Gaussian. The proposed method is evaluated on simulated data.
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