A new method for saliency detection is *** on the sparse coding model,we propose a power spectral filter to eliminate the second-order residual correlation,which suppress the global repeated items *** addition,aim to ...
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ISBN:
(纸本)9783037855409
A new method for saliency detection is *** on the sparse coding model,we propose a power spectral filter to eliminate the second-order residual correlation,which suppress the global repeated items *** addition,aim to modeling the mechanism of the human retina prior response to high-contrast stimuli,the effect of color context is *** result indicates that our method has high-quality detection performance with respect to the ability not only to highlight the salient objects in complex environment but also to pop up them uniformly.
Consumer-level digital cameras typically post-process raw captured image data to produce enhanced visually appealing output RGB images. Post-processing operations include color gamut compression, tone mapping and othe...
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ISBN:
(纸本)9781479923427
Consumer-level digital cameras typically post-process raw captured image data to produce enhanced visually appealing output RGB images. Post-processing operations include color gamut compression, tone mapping and other non-linear color corrections. However, raw image data is needed for many computer vision applications such as photometric stereo, shape from shading, and color constancy. Recovering raw image data from RGB images is complicated by the high non-linearity of the post-processing operations. In this paper, we propose a coupled dictionary scheme to model the relationship between the raw and RGB color image spaces of consumer cameras. Dictionary learning is regularized by sparsity constraints on feature representation. As well, we explore a more elaborate variant of coupled dictionary schemes that models the feature coupling more accurately. We test the proposed dictionary learning schemes on many commercial camera datasets. Our experimental results show accurate recovery of raw image data that looks visually indistinguishable from the ground truth.
The availability of 3D sensors has recently made it possible to capture depth maps in real time, which simplifies a variety of visual recognition tasks, including object/action classification, 3D reconstruction, etc. ...
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ISBN:
(纸本)9781479913480
The availability of 3D sensors has recently made it possible to capture depth maps in real time, which simplifies a variety of visual recognition tasks, including object/action classification, 3D reconstruction, etc. We address here the problems of human action recognition in depth sequences. On one hand, we present a new joint shape-motion descriptor which we call as 3D Spherical Histogram of Oriented Normal Vectors (3DS-HONV), since it is a spatio-temporal extension of the original HONV quantized in a 3D spherical coordinate. We further prove that the Optical Flow fields in depth sequences could be used in conjunction with the presented descriptor to augment the ability of capturing in-plane movements;the experiments later show that this combination is more efficient than the standalone 3DSHONV. In addition, a discriminative dictionary learning and feature representation via sparse coding is applied to proposed descriptors to relieve the intrinsic effects of noise and capture high-level patterns. By learning these sparse and distinctive representations, we demonstrate large improvements over the state-of-the-art on two challenging benchmarks, which results with an overall accuracy of 91.92% on the MSRAction3D and 93.31% on the MSRGesture3D datasets, respectively.
Complex signals such as images, audio and video recordings can be represented by a large over-complete dictionary without significant compromise on the representation quality. An over-complete dictionary has many more...
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ISBN:
(纸本)9781479900312
Complex signals such as images, audio and video recordings can be represented by a large over-complete dictionary without significant compromise on the representation quality. An over-complete dictionary has many more columns than the number of rows. Large over-complete dictionaries can produce sparse representation vectors and provide significant improvements in the reconstructed signal quality because it contains many patterns to select from. The use of the over-complete dictionaries and sparse coding has been successfully applied in compression, de-noising, and pattern recognition applications within the last few decades. An example of an over-complete dictionary that has seen a great deal of success in image processing applications is the Discrete Cosine Transform (DCT) dictionary. However, we propose a novel non-linear over-complete dictionary that improves the quality of the signal representation while reducing the number of non-zero elements to represent the signal. The proposed non-linear dictionary has demonstrated through experimental results to be superior to the DCT dictionary by achieving higher signal to noise ratio (SNR) in the reconstructed images.
While sparse coding on non-flat Riemannian manifolds has recently become increasingly popular, existing solutions either are dedicated to specific manifolds, or rely on optimization problems that are difficult to solv...
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ISBN:
(纸本)9781467369657
While sparse coding on non-flat Riemannian manifolds has recently become increasingly popular, existing solutions either are dedicated to specific manifolds, or rely on optimization problems that are difficult to solve, especially when it comes to dictionary learning. In this paper, we propose to make use of kernels to perform coding and dictionary learning on Riemannian manifolds. To this end, we introduce a general Riemannian coding framework with its kernel-based counterpart. This lets us (i) generalize beyond the special case of sparse coding;(ii) introduce efficient solutions to two coding schemes;(iii) learn the kernel parameters;(iv) perform unsupervised and supervised dictionary learning in a much simpler manner than previous Riemannian coding methods. We demonstrate the effectiveness of our approach on three different types of non-flat manifolds, and illustrate its generality by applying it to Euclidean spaces, which also are Riemannian manifolds.
We derive a stochastic EM algorithm for scalable dictionary learning with the beta-Bernoulli process, a Bayesian nonparametric prior that learns the dictionary size in addition to the sparse coding of each signal. The...
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ISBN:
(纸本)9781479988518
We derive a stochastic EM algorithm for scalable dictionary learning with the beta-Bernoulli process, a Bayesian nonparametric prior that learns the dictionary size in addition to the sparse coding of each signal. The core EM algorithm provides a new way for doing inference in nonparametric dictionary learning models and has a close similarity to other sparse coding methods such as K-SVD. Our stochastic extension for handling large data sets is closely related to stochastic variational inference, with the stochastic update for one parameter exactly that found using SVI. We show our algorithm compares well with K-SVD and total variation minimization on a denoising problem using several images.
Spectral analysis is widely used in various detection activities,unfortunately,the detection accuracy is greatly reduced due to the interference of multiple noises in the spectrum data acquisition *** order to remove ...
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Spectral analysis is widely used in various detection activities,unfortunately,the detection accuracy is greatly reduced due to the interference of multiple noises in the spectrum data acquisition *** order to remove the mixed noise in the spectrum data and improve the detection accuracy,we propose a low-rank recovery dictionary learning ***,the method considers the effects of multiple noises of Gaussian noise and sparse noise,and establishes a dictionary learning model that can reduce these ***,the corresponding optimization method is designed to solve the ***,relevant experiments show the feasibility and superiority of the proposed spectrum data denoising method.
The reconstruction performance of an orthogonal matching pursuit algorithm is poor due to less observation values. An observation matrix design method which can adaptively ensure the sample size based on the image inf...
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ISBN:
(纸本)9781467352512
The reconstruction performance of an orthogonal matching pursuit algorithm is poor due to less observation values. An observation matrix design method which can adaptively ensure the sample size based on the image information is proposed. To make the algorithm more sparsely representative, an adaptive orthogonal matching pursuit algorithm based on the redundant dictionary is discussed by using a K-SVD dictionary training method to get a sparse dictionary. Experimental results show that the algorithm not only solves the problem that the sample size is small, but also improves the image reconstruction quality.
Dictionary learning through matrix factorization has become widely popular for performing music transcription and source separation. These methods learn a concise set of dictionary atoms which represent spectrograms o...
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ISBN:
(纸本)9781424442959;9781424442966
Dictionary learning through matrix factorization has become widely popular for performing music transcription and source separation. These methods learn a concise set of dictionary atoms which represent spectrograms of musical objects. However, there is no guarantee that the atoms learned will be perceptually meaningful, particularly when there exists significant spectral and temporal overlap among the musical sources. In this paper, we propose a novel dictionary learning method that imposes additional harmonic constraints upon the atoms of the learned dictionary while allowing the dictionary size to grow appropriately during the learning procedure. When there is significant spectral-temporal overlap among the musical sources, our method outperforms popular existing matrix factorization methods as measured by the recall and precision of learned dictionary atoms.
In this paper, we propose a supervised dictionary learning algorithm that aims to preserve the local geometry in both dimensions of the data. A graph-based regularization explicitly takes into account the local manifo...
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ISBN:
(纸本)9781509041183
In this paper, we propose a supervised dictionary learning algorithm that aims to preserve the local geometry in both dimensions of the data. A graph-based regularization explicitly takes into account the local manifold structure of the observations. A second graph regularization gives similar treatment to the feature domain and helps in learning a more robust dictionary. Both graphs can be constructed from the training data or learned and adapted along the dictionary learning process. The combination of these two terms promotes the discriminative power of the learned sparse representations and leads to improved classification accuracy. The proposed method was evaluated on several different datasets, representing both single-label and multi-label classification problems, and demonstrated better performance compared with other dictionary based approaches.
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