1614986
Adaptively weighted sub-pattern PCA for face recognition
Adaptively weighted Sub-pattern PCA (Aw-SpPCA) for face recognition is presented in this paper. Unlike PCA based on a whole image pattern, Aw-SpPCA operates directly on its sub-patterns partitioned from an original whole pattern and separately extracts features from them. Moreover, unlike both SpPCA and mPCA that neglect different contributions made by different parts of the human face in face recognition, Aw-SpPCA can adaptively compute the contributions of each part and then endows them to a classification task in order to enhance the robustness to both expression and illumination variations. Experiments on three standard face databases show that the proposed method is competitive.
120730704
Robust image denoising using kernel-induced measures
We propose a class of novel nonlinear robust filters for image denoising by incorporating the kernel-induced measures into the classical linear mean filter. Particularly, we place more focus on the Gaussian kernel based filter (GK) due to its simplicity. The GK filter not only generalizes and makes the original linear mean filter highly resistant to outliers but also outperforms a typical and powerful mean-logCauchy filter recently developed by Hamza et al in the mixed noise removal in certain specific conditions in the normalized mean square error (NMSE) sense. The experimental results also illustrate that the kernel-based nonlinear filters are promising.
12986050
Improving the Robustness of ‘Online Agglomerative Clustering Method’ Based on Kernel-Induce Distance Measures
Recently, an online agglomerative clustering method called AddC (I. D. Guedalia et al. Neural Comput. {\bf 11} (1999), 521--540) was proposed for nonstationary data clustering. Although AddC possesses many good attributes, a vital problem of that method is its sensitivity to noises, which limits its use in real-word applications. In this paper, based on \hbox{kernel-induced} distance measures, a robust online clustering (ROC) algorithm is proposed to remedy the problem of AddC. Experimental results on artificial and benchmark data sets show that ROC has better clustering performances than AddC, while still inheriting advantages such as clustering data in a single pass and without knowing the exact number of clusters beforehand.
6776829
Semi-supervised Kernel-Based Fuzzy C-Means
This paper presents a semi-supervised kernel-based fuzzy c-means algorithm called S 2 KFCM by introducing semi-supervised learning technique and the kernel method simultaneously into conventional fuzzy clustering algo- rithm. Through using labeled and unlabeled data together, S 2 KFCM can be ap- plied to both clustering and classification tasks. However, only the latter is con- cerned in this paper. Experimental results show that S 2 KFCM can improve classification accuracy significantly, compared with conventional classifiers trained with a small number of labeled data only. Also, it outperforms a similar approach S 2 FCM.
29253397
Tabu-Based Exploratory Evolutionary Algorithm for Effective Multi-objective Optimization
This paper proposes an exploratory multi-objective evolutionary algorithm (EMOEA) that makes use of the integrated features of tabu search and evolutionary algorithms for effective multi-objective optimization. It incorporates a tabu list and tabu constraint for individual examination and preservation to enhance the evolutionary search diversity in multi-objective optimization, which subsequently helps to avoid the search from trapping in local optima and at the same time, promotes the evolution towards the global Pareto-front. A novel method of lateral interference is also suggested, which is capable of distributing non-dominated individuals uniformly along the discovered Pareto-front at each generation. Unlike existing niching/sharing methods, lateral interference can be performed without the need of any parameter setting and can be flexibly applied in either parameter or objective domain depending on the nature of the optimization problem involved. The proposed features are experimented in order to illustrate their behavior and usefulness in the algorithm.
206017109
Design and real-time implementation of a multivariable gyro-mirror line-of-sight stabilization platform
Gyro-mirror line-of-sight stabilization platform is a nonlinear, multivariable and highly coupled system. It forms the basis of a wide range of practical instruments used for the purposes of sighting and targeting in both surface and airborne vehicles, which is capable of maintaining the sightline of a mirror when it is subjected to external disturbances. However, a spinning gyro has a property known as precession such that when a torque is applied to one axis, it will contrary to the intuition of mechanics, and results the rotation in the direction of another axis. This behavior poses a problem in controlling the line-of-sight since movement about one axis will cause a coupled movement in the other. In this paper, an efficient full-matrix fuzzy logic controller is designed and implemented for a practical nonlinear gyro-mirror line-of-sight stabilization platform Both simulation and real-time experimental results demonstrate the effectiveness of the designed full-matrix fuzzy gyroscope control system, which offers an excellent closed-loop response for the transient and tracking performances, with significant reduction in the coupling effect against cross-axis interactions.
10451148
Discontinuity preserving stereo with small baseline multi-flash illumination
Currently, sharp discontinuities in depth and partial occlusions in multiview imaging systems pose serious challenges for many dense correspondence algorithms. However, it is important for 3D reconstruction methods to preserve depth edges as they correspond to important shape features like silhouettes which are critical for understanding the structure of a scene. In this paper, we show how active illumination algorithms can produce a rich set of feature maps that are useful in dense 3D reconstruction. We start by showing a method to compute a qualitative depth map from a single camera, which encodes object relative distances and can be used as a prior for stereo. In a multiview setup, we show that along with depth edges, binocular half-occluded pixels can also be explicitly and reliably labeled. To demonstrate the usefulness of these feature maps, we show how they can be used in two different algorithms for dense stereo correspondence. Our experimental results show that our enhanced stereo algorithms are able to extract high quality, discontinuity preserving correspondence maps from scenes that are extremely challenging for conventional stereo methods.
16227528
Fast image retrieval using color-spatial information
Abstract. In this paper, we present an image retrieval system that employs both the color and spatial information of images to facilitate the retrieval process. The basic unit used in our technique is a single-colored cluster, which bounds a homogeneous region of that color in an image. Two clusters from two images are similar if they are of the same color and overlap in the image space. The number of clusters that can be extracted from an image can be very large, and it affects the accuracy of retrieval. We study the effect of the number of clusters on retrieval effectiveness to determine an appropriate value for “optimal'' performance. To facilitate efficient retrieval, we also propose a multi-tier indexing mechanism called the Sequenced Multi-Attribute Tree (SMAT). We implemented a two-tier SMAT, where the first layer is used to prune away clusters that are of different colors, while the second layer discriminates clusters of different spatial locality. We conducted an experimental study on an image database consisting of 12,000 images. Our results show the effectiveness of the proposed color-spatial approach, and the efficiency of the proposed indexing mechanism.
6439034
Efficient Image Retrieval By Color Contents
Images are becoming an important asset and managing them for efficient retrieval poses challenges to the database community. In this paper, we proposed a novel three-tier color index that supports efficient image retrieval by color contents which is important to certain applications, especially when shapes and semantic objects cannot be easily recognized. A prototype painting database system is designed and implemented to demonstrate the effectiveness of the proposed indexing technique. Besides the color index, two other indexes, B+-trees for structured attributes and a signature file for free-text descriptions, were also implemented. As a result, a wide range of queries, both text-based and content-based can be processed efficiently. We also look at existing image database systems based on their query retrieval capabilities.