Top PDF A Probabilistic Approach to Human Motion Detection and Labeling

A Probabilistic Approach to Human Motion Detection and Labeling

A Probabilistic Approach to Human Motion Detection and Labeling

than other labelings. This is in contrast to the situation of gray-scale images where there can be many close candidate features for one body part and therefore many labelings may be comparable. Since the winner-take-all strategy works better on motion capture data, we will use it as the detection method in the later experiments

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Probabilistic Motion Diffusion of Labeling Priors for Coherent Video Segmentation

Probabilistic Motion Diffusion of Labeling Priors for Coherent Video Segmentation

4 × 4: Improved performance of the proposed method vs. state of the art on face and hands in “MONKEYBAR”. 2 × 1 Failures cases of the proposed approach, although outperforming compared methods some mislabelling of the hair in “MONKEYBAR” and loss of spatial coherence on hat in “DANCE” can be observed. In both cases these can be attributed to colour texture similarity in the presence of erratic motion. optimization. The benefits of the probabilistic approach are observed on the feet of the child; hard assignment causes incorrect pixel assignments to cumulatively trail the feet over time. Although soft assignment alone causes minor loss of spatial coherence, this is avoided in our proposed system through incorporation of the super-pixel constraint to produce results such as those of Fig. 5(b).
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An Unsupervised Probabilistic Approach for the Detection of Outliers in Corpora

An Unsupervised Probabilistic Approach for the Detection of Outliers in Corpora

some initial results of its use on artificially created collec- tions. The results illustrate that for large segments of text it is possible to achieve fairly good results detecting out- liers in some types of corpora. For instance, an average of 92% of translations of chinese news stories can be identi- fied in corpora composed of newswire with a precision of 71.9%. This is a very good result given that this procedure is completely unsupervised and makes use of no training data. The fact versus opinion experiments proved to be a much more difficult task and on average achieve only a 61% F -measure for large pieces of text. These results are somewhat disappointing, but this is a difficult task as we are attempting to label every piece of text as either an outlier or non-outlier. The results of this labeling are closely tied to the cutoff used for determining which observations are farthest away from the rest of the data. While choosing a cutoff to automatically separate outliers from non-outliers is difficult, other experimental results (Guthrie, 2008) per- formed on these corpora indicate that using this detection method often results in the outlying piece of text having the greatest distance from the rest of the corpus. Further research is ongoing to see if this cutoff can be more intel- ligently chosen to improve the accuracy of results on this task.
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A Comparative Approach for Human Motion Detection & Tracking System

A Comparative Approach for Human Motion Detection & Tracking System

The proposed system works in three stages. At first stage gray scale frames are extracted from video & frame difference between frame Fn-2 and Fn-1 and second frame difference between the frame Fn-1 and current frame Fn are taken. It is different than other algorithms where only the difference between the current and previous frame is considered. In second phase, morphological operation is performed on the resultant frame difference to suppress the remaining errors. Then the background regions are extracted, holes are filled and small regions are removed. It gives, two background masks, after morphological operations which are then compared with the threshold calculated followed by the AND operation applied to eliminate the false motion detection. Finally, the Kalman filter [11] is used to remove the noise and other changes in pixel due to illumination or any other reason. Extracted foreground is then tracked by the rectangle around it. The system is depicted as figure 1 below.
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A Probabilistic Approach for Human Everyday Activities Recognition using Body Motion from RGB-D Images

A Probabilistic Approach for Human Everyday Activities Recognition using Body Motion from RGB-D Images

A Probabilistic Approach for Human Everyday Activities Recognition using Body Motion from RGB-D Images Diego R. Faria, Cristiano Premebida and Urbano Nunes Abstract— In this work, we propose an approach that relies on cues from depth perception from RGB-D images, where features related to human body motion (3D skeleton features) are used on multiple learning classifiers in order to recog- nize human activities on a benchmark dataset. A Dynamic Bayesian Mixture Model (DBMM) is designed to combine multiple classifier likelihoods into a single form, assigning weights (by an uncertainty measure) to counterbalance the likelihoods as a posterior probability. Temporal information is incorporated in the DBMM by means of prior probabilities, taking into consideration previous probabilistic inference to reinforce current-frame classification. The publicly available Cornell Activity Dataset [1] with 12 different human activities was used to evaluate the proposed approach. Reported results on testing dataset show that our approach overcomes state of the art methods in terms of precision, recall and overall accuracy. The developed work allows the use of activities classification for applications where the human behaviour recognition is important, such as human-robot interaction, assisted living for elderly care, among others.
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A probabilistic graphical model approach to solving the structure and motion problem

A probabilistic graphical model approach to solving the structure and motion problem

matching can take place. We now discuss and compare some of the alternative detecting and descriptor methods. A summary of popular feature detectors and descriptors can be seen in Table 2.1. We categorise feature detection into two approaches: blob detection and corner detection. Blob detectors detect local extrema of the response of scale-space type filters, such as the DoG filter used by SIFT. The main aim of SURF is to offer a computationally efficient alternative to SIFT detection. As a results the DoG filter is estimated by applying box filters with an efficient implementation using integral images, as a trade-off in accuracy. Similarly, the CenSurE feature detector uses this speeded up filtering process, but without using octaves of different sizes, i.e. the scale-space used when filtering is always the full image size. This is an attempt to find more stable features at the higher levels of the scale-space pyramid.
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A fuzzy probabilistic inference methodology for constrained 3D human motion classification

A fuzzy probabilistic inference methodology for constrained 3D human motion classification

3.2.1.4 Membership score evaluation Instances of moves are classified by evaluating their membership scores to the Fuzzy Membership Functions generated by FQG. A posture being defined by a set of 57 Euler angles is modelled by 57 Fuzzy Membership Functions. Having no initial prior knowl- edge about the eventual predominance of some of these joints, the overall membership of a test instance to a known move is computed by calculating the average of all the 57 membership scores of the Euler Angles. This approach could probably be improved in the near future by introducing weighted average for certain joints (for example, the position of the elbow might be more important than the position of the knee when in guard). A parameter 𝑡 expresses the membership threshold to a move. In practice, all frames with a membership score equal or greater than 𝑡 are classified as belonging to that move. The lower the value of 𝑡, the lower is the selectivity of the classifier, and the higher the value of 𝑡, the more difficult it becomes for a move to be given a membership score of 1. When the same frame has a high membership score for several fuzzy sets representing different moves, an order of preference of these sets can be established by comparing the Euclidean distance of the observed data to the centroid of each fuzzy set. The existence of 𝑡 allows the introduction of a convenient a-posteriori way to fine tune parameters in order to tailor the precision of every model to the quantity of avail- able learning data for each move. If results show that the relative size 𝑠 of a learning sample for given move was over-estimated, the membership scores 𝑚 𝑖 can be re-scaled
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Precis of Bayesian Rationality: The Probabilistic Approach to Human Reasoning

Precis of Bayesian Rationality: The Probabilistic Approach to Human Reasoning

Recently, we have also applied this model to rules that contain emotional content, for example, if you clean up blood, then you must wear gloves (Perham & Oaksford 2005). With the goal of detecting cheaters (Cosmides 1989), you will look at people who are not cleaning up blood but who are wearing gloves ( : p, q). With the goal of detecting people who may come to harm, you will want to check people who are cleaning up blood but who are not wearing gloves ( p, : q). Perham and Oaksford (2005) set up contexts in which cheater detection should dominate, but in which the goal of detecting people who may come to harm may still be in play. That is, U( : p, q) . U(p, : q) . 0. The threatening word “blood” can appear for either the p, q case or the p, : q case. In calculating generalized expected utility (Zeelen- berg et al. 2000), a regret term (Re) is subtracted from the expected utility of an act of detection, if the resulting state of the world is anticipated to be threatening. For example, by checking someone who is not wearing gloves ( : q), to see if they are at risk of harm, one must anticipate encountering blood (p). Because “blood” is a threatening word, the utility for the participant of turning a : q card is reduced; that is, the utility of encoun- tering a p, : q card is now U(p, : q) – Re, for regret term Re. Consequently, selections of the “not wearing gloves” card ( : q) should be lower for our blood rule than for a rule that does not contain a threatening antecedent, such as, if you clean up packaging, then you must wear gloves. In two experiments, Perham and Oaksford (2005) observed just this effect. When participants’ primary goal was to detect cheaters, their levels of : p and q card selec- tion were the same for the threat (blood rule) as for the no- threat rule. However, their levels of p and : q card selec- tion were significantly lower for the threatening than for the non-threatening rules. This finding is important because it runs counter to alternative theories, in particu- lar the evolutionary approach (Cosmides 1989; Cosmides & Tooby 2000), which makes the opposite prediction, that p and : q card selections should, if anything, increase for threat rules.
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Human Motion Analysis via Statistical Motion Processing and Sequential Change Detection

Human Motion Analysis via Statistical Motion Processing and Sequential Change Detection

8. Conclusions In this work, a novel approach for the analysis of human motion in video is presented. The kurtosis of interframe illumination variations leads to binary masks, the Activity Areas, which indicate which pixels are active throughout the video. The temporal evolution of the activities is character- ized by temporally weighted versions of the Activity Areas, the Activity History Areas. Changes in the activity taking place are detected via sequential change detection, applied on the interframe illumination variations. This separates the video into sequences containing different activities, based on changes in their motion. The activity taking place in each subsequence is then characterized by the shape of its Activity Area or on its magnitude and direction, derived from the Activity History Area. For nontranslational activities, Fourier Shape Descriptors represent the shape of each Activity Area, and are compared with each other, for recognition. Translational motions are characterized based on their relative magnitude and direction, which are retrieved from their Activity History Areas. The combined use of the aforementioned recognition techniques with the proposed sequential change detection for the separation of the video in sequences containing separate activities leads to successful recognition results at a low computational cost.
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Monocular 3D Human Motion Tracking Using Dynamic Probabilistic Latent Semantic Analysis

Monocular 3D Human Motion Tracking Using Dynamic Probabilistic Latent Semantic Analysis

This approach is in contrast to many current methods that directly learn the often high-dimensional image-to-pose mappings and utilize subspace projections as a constraint on the pose space alone. As a consequence, such mappings may often exhibit increased computational complexity and insufficient generalization performance. We demonstrate the utility of the proposed model on the synthetic dataset and the task of 3D human motion tracking in monocular image sequences with arbitrary camera views. Our experiments show that the dynamic PLSA approach can produce accurate pose estimates at a fraction of the computational cost of alternative subspace tracking methods.
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Probabilistic Labeling for Efficient Referential Grounding based on Collaborative Discourse

Probabilistic Labeling for Efficient Referential Grounding based on Collaborative Discourse

This data has demonstrated the importance of in- corporating collaborative discourse for referential grounding. Based on this data, as a first step we developed a graph-matching approach for referential ground- ing (Liu et al., 2012; Liu et al., 2013). This ap- proach uses Attributed Relational Graph to cap- ture collaborative discourse and employs a state- space search algorithm to find proper ground- ing results. Although it has made meaning- ful progress in addressing collaborative referen- tial grounding under mismatched perceptions, the state-space search based approach has two ma- jor limitations. First, it is neither flexible to ob- tain multiple grounding hypotheses, nor flexible to incorporate different hypotheses incrementally for follow-up grounding. Second, the search al- gorithm tends to have a high time complexity for optimal solutions. Thus, the previous approach is not ideal for collaborative and incremental di- alogue systems that interact with human users in real time.
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A Modern Approach for Motion Detection and Responsive Control of Appliance Using MATLAB

A Modern Approach for Motion Detection and Responsive Control of Appliance Using MATLAB

P.G Student, Dept. of Communication Systems (ECE), Idhaya Engineering College for Women, Chinnasalem, India. 1 Assistant Professor, Dept. of Electronics and Communication Engineering, Idhaya Engineering College for Women, Chinnasalem, India. 2 ABSTRACT: Motion tracking is a major issue in security field whether it is borders, banks, offices and institutions etc. Security is always maximum concerned. To maintain security we deploy security guards but with them human errors are most common as they cannot available on a place all the time. Hardware sensor based systems are very costly and maximum lasts for few years only. it can be placed on single place. This paper proposes to create motion detection system using software. It deals with the concept of motion tracking using cameras in real time. It is designed to create a visitor identification system in which motion is detected MATLAB system reads predefined message.
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A Modern Approach for Motion Detection and Responsive Control of Appliance using MATLAB

A Modern Approach for Motion Detection and Responsive Control of Appliance using MATLAB

Department of Electronics & Communication Engineering Department of Computer Science & Engineering Idhaya Engineering College for Women, Chinnasalem, India Idhaya Engineering College for Women, Chinnasalem, India Abstract Motion tracking is a major issue in security field whether it is borders, banks, offices and institutions etc. Security is always maximum concerned. To maintain security we deploy security guards but with them human errors are most common as they cannot available on a place all the time. Hardware sensor based systems are very costly and maximum lasts for few years only.it can be placed on single place. This paper proposes to create motion detection system using software. It deals with the concept of motion tracking using cameras in real time. It is designed to create a visitor identification system in which motion is detected MATLAB system reads predefined message.
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Vision based approach to human fall detection

Vision based approach to human fall detection

Keywords — Activity analysis, chute dataset, fall detection, openCV, Silhouette, motion history image, background subtraction INTRODUCTION The contents of each section may be provided to understand easily about the paper. Falls are one of the major risk for seniors living alone at home, sometimes causing injuries. Nowadays, the usual solution to detect falls is to use some wearable sensors like accelerometers or help buttons. However, the problem of such detectors is that older people often forget to wear them. Moreover, in the case of a help button, it can be useless if the person is unconscious or immobilized. To overcome these limitations, we use a computer vision system which doesn’t require that the person wears anything. Another advantage of such a system is that a camera gives more information on the motion of a person and his/her actions than an accelerometer.
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Bridging the Gap between Detection and Tracking for 3D Human Motion Recovery

Bridging the Gap between Detection and Tracking for 3D Human Motion Recovery

Furthermore, the approach proposed in Chapter 5 can handle motions in which such key-poses are not defined, but there is still a clear relation between some easily measurable image quantities and the body configuration, as for example skating where the trajectory followed by a subject is highly correlated to how the subject articulates. Our technique uses these easily retrievable image measurements as latent variables from which we can recover 3D human body motion via a Gaussian Process mapping. By contrast with state-of-the-art approaches that consider the latent variables as unknowns, learning our mapping involves very few parameters and is therefore much easier to do. It allows us to recover 3D motion from monocular video sequences without having to manually initialize either the poses or the latent variables. We have demonstrated this approach on challenging activities such as roller skating, skiing, and golfing. A potential extension would be to look into more complex activities for which some of the latent variables are indeed observable and others not. In these cases, such as when the person’s individual style truly matters, we will look at hybrid approaches where we will establish a first mapping using the approach presented here and then learn a second mapping modeling deviations from what the first predicts. Because the first mapping will have captured much of the complexity, it is hoped that the second will be easy to learn, even in these difficult cases.
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Human Motion Detection in Video Surveillance using Computer Vision Technique

Human Motion Detection in Video Surveillance using Computer Vision Technique

Alternatively, background subtraction compares images with a background model and detects the changes as objects. It usually assumes that no object appears in images when building the background model. Such requirements of training examples for object or background modeling actually limit the applicability of above-mentioned methods in automated video analysis Another category of object detection methods that can avoid training phases are motion- based methods which only use motion information to separate objects from the background. Given a sequence of images in which foreground objects are present and moving differently from the background, can we separate the objects from the background automatically. The goal is to take the image sequence as input and directly output a mask sequence. The most natural way for motion-based object detection is to classify pixels according to motion patterns, which is usually named motion segmentation. These approaches achieve both segmentation and optical flow computation accurately and they can work in the presence of large camera motion. However, they assume rigid motion or smooth motion in respective regions, which is not generally true in practice. In practice, the foreground motion can be very complicated with nonrigid shape changes. Also, the background may be complex, including illumination changes and varying textures such as waving trees and sea waves. The video includes an operating escalator, but it should be regarded as background for human tracking purpose. An alternative motion-based approach is background estimation.
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A Probabilistic Approach to Text Generation of Human Motions extracted from Kinect Videos

A Probabilistic Approach to Text Generation of Human Motions extracted from Kinect Videos

Fig. 1. Overview of probabilistic text generation of human motions are recorded by tracking multiple joints of human skeleton with the libraries for a Kinect camera[14]. Several dimension reduction procedures are applied to the observed time-series data, and then the analyzed data are stored in a data base with the intermediate representations which correspond to the se- mantics of human motions and bridge the gap between time- series data and natural language sentences. After that, by adopting machine learning for the correspondence between analyzed time-series data and an intermediate representation, we build a human motion identifier with visual information as input information. To build linguistic resources used for text generation, we conduct a subject experiment to collect sentences which describe human motions and then build bi-gram models based on the collected sentences for each intermediate representation. So, once an intermediate representation is selected, a corresponding bi-gram model to the representation is selected, and then the most likely combination of words is selected as a linguistic summary for the human motion by applying dynamic programming to the selected bi-gram model.
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Probabilistic motion pixel detection for the reduction of ghost artifacts in high dynamic range images from multiple exposures

Probabilistic motion pixel detection for the reduction of ghost artifacts in high dynamic range images from multiple exposures

Figure 14 Another comparison of results for a set of multi-exposure images. (a) Multi-exposure images. (b) Result by the median threshold bitmap approach [22]. (c) Gradient domain approach [23]. (d) PatchMatch-based method [30]. (e) Low-rank matrix-based approach [21]. (f) The proposed method. It is noted that our method has some limitations when the selected reference has ‘saturated and moving’ fore- ground object. For example, Figure 15a shows a set of multi-exposure images where the third image is selected as the reference frame because it has the largest area of well-contrast region in the background. In this case, the proposed algorithm yields the fusion result as shown in Figure 15c because the foreground object is moving and hence excluded from the fusion process. On the other hand, since the algorithm in [17] sets the first image as the reference and tries to track the inconsistent pixels, it keeps the foreground object very well as shown in Figure 15b.
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An MRF based abnormal event detection approach using motion and appearance features

An MRF based abnormal event detection approach using motion and appearance features

Features have to be descriptive enough to extract the im- portant information about the normal behavior pertaining to the context in consideration. Here in this work we consider the context of pedestrian walkways, and anything which stands out from the normal behavior, such as high speed objects and the presence of abnormal objects, are consid- ered to be anomalies. State of the art feature vectors do not completely describe the human motion behavior, which has its own unique characteristics such as variation in the mo- tion features across the human body due to the non-linear nature and the repetitiveness of the limb movements. Here in this work we propose two features named optical acceler- ation and the histogram of optical flow gradients, to extract information about the temporal and spatial variations in the optical flow respectively.
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Human Motion Detection

Human Motion Detection

1.2 Objectives Project The idea of this project comes from the widely increment of burglaries. A simple security system is basic and only offers simple password lock and sensors. Hence this project would like to enhance the simple security system with a special sensor that quickly detect human motion and is built in with GSM device that can send an SMS to the owner. The project is known as Human Motion Detection. And the objectives of the project are:

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