International Journal of Pattern Recognition and Artificial Intelligence

In this paper, we design a robust and friendly human–robot interface (HRI) system for our intelligent mobile robot based only on natural human gestures. It consists of a triple-face detection method and a fuzzy logic controller (FLC)-Kalman filter tracking system to check the users and predict their current position in a dynamic and cluttered working environment. In addition, through the combined classifier of the principal component analysis (PCA) and back-propagation artificial neural network (BPANN), single and successive commands defined by facial positions and hand gestures are identified for real-time command recognition after dynamic programming (DP). Therefore, the users can instruct this HRI system to make member recognition or expression recognition corresponding to their gesture commands, respectively based on the linear discriminant analysis (LDA) and BPANN. The experimental results prove that the proposed HRI system perform accurately in real-time face detection and tracking, and robustly react to the corresponding gesture commands at eight frames per second (fps).

In this paper, we present a novel approach to imaging a panoramic (360°) environment and computing its dense depth map. Our approach adopts a multi-baseline stereo strategy using a set of multi-perspective panoramas where large baseline lengths are available. We design two image acquisition rigs for capturing such multi-perspective panoramas. The first one is composed of two parallel stereo cameras. By rotating the rig about a vertical axis, we generate four multi-perspective panoramas by resampling the regular perspective images captured by the stereo cameras. Then a depth map is estimated from the four multi-perspective panoramas and an original perspective image using a multi-baseline matching technique with different types of epipolar constraints. The second one is composed of a single camera and two mirrors. By rotating the rig, we acquire a spatio-temporal volume that is made up of the sequential images captured by the camera. Then we estimate a depth map by extracting trajectories from the spatio-temporal volume by using a multi-baseline stereo technique by considering occlusions. We can consider both rotating rigs as a single rotating camera with a very large field of view (FOV), that offers a large baseline length in depth estimation. In addition, compared with a previous approach using two multi-perspective panoramas from a single rotating camera, our approach can reduce matching errors due to image noise, repeated patterns, and occlusions by multi-baseline stereo techniques. Experimental results using both synthetic and real images show that our approach produces high quality panoramic 3D reconstruction.

The Euclidean distance transform (EDT) is used in various methods in pattern recognition, computer vision, image analysis, physics, applied mathematics and robotics. Until now, several sequential EDT algorithms have been described in the literature, however they are time- and memory-consuming for images with large resolutions. Therefore, parallel implementations of the EDT are required specially for 3D images. This paper presents a parallel implementation based on domain decomposition of a well-known 3D Euclidean distance transform algorithm, and analyzes its performance on a cluster of workstations. The use of a data compression tool to reduce communication time is investigated and discussed. Among the obtained performance results, this work shows that data compression is an essential tool for clusters with low-bandwidth networks.

Photography, lithography, xerography, and inkjet printing are the dominant technologies for color printing. Images produced on these "different media" are often scanned either for the purpose of copying or creating an electronic representation. For an improved color calibration during scanning, a media identification from the scanned image data is desirable. In this paper, we propose an efficient algorithm for automated classification of input media into four major classes corresponding to photographic, lithographic, xerographic and inkjet. Our technique exploits the strong correlation between the type of input media and the spatial statistics of corresponding images, which are observed in the scanned images. We adopt ideas from spatial statistics literature, and design two spatial statistical measures of dispersion and periodicity, which are computed over spatial point patterns generated from blocks of the scanned image, and whose distributions provide the features for making a decision. We utilize extensive training data and determined well separated decision regions to classify the input media. We validate and tested our classification technique results over an independent extensive data set. The results demonstrate that the proposed method is able to distinguish between the different media with high reliability.

Graphic designers and developers would like to use virtual reality (VR) systems with a friendly Graphical User Interface (GUI) and development environment that provide efficient creation, modification and deletion functions. Although current VR graphical design systems incorporate the most up-to-date features, graphic designers are not able to specify the interface features that they desire or features that are most suitable for specific design and development tasks. This paper proposes an Open Module Development Environment (OMDE) for VR systems that can provide interactive functions that reflect the graphic designers requirements. OMDE allows graphic designers to specify their specific interface features and functions, and the system configuration to utilize plug-in modules. Hence a dynamically created development environment is provided that is also tailored to the graphic designer's requirements and facilitates graphical composition and editing. The functions of the graphical interface modules and the OMDE system specifications are identified. The system implementation environment and structure of the 3D VR software are described and the implementation is evaluated for performance, as an improved 3D graphic design tool.

This paper presents a new segmentation method based on division of space which chooses principal curves to extract strokes of characters and form the initial stroke set. The strokes in the initial set are disposed by the fuzzy theorems and grouped based on the confidence of the classifiers. The training sample space is constructed by the Affinity Propagation (AP) algorithm and the Biomimetic Pattern Recognition (BPR) theory. The strokes are arranged in a sequence divided by calculating the distance of each subsequence to the relative subspace. Finally, with the maximum posterior (MAP) criterion, the optimal segmentation hypotheses described in a probabilistic model is found. Our system is validated by experimental results from samples of real Chinese bank checks, achieving a correct rate of without 95.23% rejection.

In this paper, a novel method from the feature — porno-sounds recognition — point of view is proposed to detect adult video sequences automatically which may serve as a verification step, a supplementary method or an independent detector. To the specificity of erotic sound, its feature analysis is given. Based on the popular features, histograms and contours are introduced as new sets of features. At the same time due to the complexity of outside data, a general framework called in-class clustering is proposed which selects the most representative subclass for training and classification. All these efforts increase the recall rate and decrease the false positive rate. Experiments on real data from the Internet indicate that the proposed method yields superior performance with 89.17% recall rate and 10.78% false positive rate being achieved.

In order to mine association rules accurately and efficiently while preserving the privacy thereof, a novel privacy-preserving association rules mining method is proposed in this paper. Known as the partial randomized response based on probability matrix, or PRRPM, this method chooses different data transition strategies to find frequent 1-itemsets and k-itemsets (k > 1). The PRRPM algorithm is explored and its validity examined through theoretical analysis and experiments.