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Estimation of density and direction of crowd flow from surveillance video has attracted much research attention recently in the area of computer vision. Crowd density in a video sequence can be considered as a global entity to estimate the direction of interest of the crowd. Though there are methods to compute the density and direction, a combined approach will give more insights into the problem...
We present a new method of estimating disparity maps from stereo videos for bokeh effect synthesis. In this work, we develop an improved total variation regularization and the robust L1 norm in the data fidelity term (TV-L1) [4] based method to estimate edge-preserving disparity map without stereo rectification. The proposed algorithm improves the TV-L1 approach by incorporating structure edge detection,...
In this paper, we propose a method that automatically estimates surgical phases in a specified workflow with a multi-camera system. More specifically, our goal is to output an appropriate phase label for each one-second of input videos captured by multiple cameras in an operating room. The fundamental idea behind our work lies in constructing a hidden Markov model based on motion features, which are...
In this paper, we present a robust method to improve the accuracy of phases segmentation problem in a specified surgical workflow (SW) by learning a topic model from the optical flow (OF) motion features of general working contexts, such as the medical staffs, equipments and materials. We have an awareness of such working contexts by capturing the SW with multiple synchronized cameras. The main problems...
Endoscopic images provide doctors with valuable information in both diagnosis and surgery. In a thoracoscopic surgery, locating lung part based on endoscopic images is difficult since lungs vary sharply according to respiration. In this case, correctly extracting lung part plays a crucial role in intraoperative navigation. Although many efficient image segmentation approaches have been developed in...
Spoofing attack can easily deceive face recognition system. In this paper, we explore the issue of face anti-spoofing with good performance in accuracy by utilizing optical flow vector on two types of attacks: photos and videos shown on high-resolution electronic screens. The key idea is to calculate the displacement of optical flow vector between two successive frames of a face video and obtain a...
Haze and rain removal from video is a complex task as the visual impact of those are im-penetrable. In this paper an algorithm is put forward which can remove haze and rain simultaneously. This algorithm can be used for real time applications such as driving assistance and for security surveillance. To remove haze, the initial image has to undergo two processes namely contrast enhancement and white...
We present a new approach for motion estimation from digital videos based on the use of 2D amplitude-modulation frequency-modulation (AM-FM) models. The proposed approach uses an AM-FM representation to derive AM and FM based equations that can be applied to two consecutive frames to derive motion estimates. We test the proposed method using complex synthetic examples, with both amplitude-modulated...
Face detection is an important task in the field of computer vision, which is widely used in the field of security, human-machine interaction, identity recognition, and etc. Many existing methods are developed for image based face pose estimation, but few of them can be directly extended to videos. However, video-based face pose estimation is much more important and frequently used in real applications...
This paper presents an automated analytics system which monitors the students attending online lectures from a remote location and provides feedback to the teacher. The classroom videos are recorded and analyzed to identify the student trends, which might not be noticed by a teacher during class hours. Student behaviors are classified into five affective states: Active, Transcribing, Unavailing, Distracted...
Respiration rate (RR) is one of the important vital signs used for clinical monitoring of neonates in intensive care units. Due to the fragile skin of the neonates, it is preferable to have monitoring systems with minimal contact with the neonate. Recently, several methods have been proposed for contact-free monitoring of vital signs using a video camera. Detection of the chest-and-abdomen region...
We propose a measurement method for the mean speed distribution of collective motions of highly dense groups with optical flow in this paper. This measurement is fundamental for ecological investigations and mathematical modeling of collective animal behaviors, including human crowds. Our method is applicable to highly dense homogeneous groups wherein individual movements are approximately uniform...
We present a first approach to a new method to compute the motion estimation in digital videos using the two-dimensional instantaneous frequency information computed using amplitude-modulation frequency-modulation (AM-FM) methods. The optical flow vectors are computed using an iteratively reweighted norm for total variation (IRN-TV) algorithm. We compare the proposed method using synthetic videos...
This paper proposes a novel perceptual video quality assessment metric for streamed videos using optical flow statistical features. We analyze the impact of network losses on the decoded videos and the resulting error propagation. We show that the statistical features of the optical flow of the corrupted frames can be used to measure the distortion in the received video. We show that this approach...
Digital video is becoming an emerging force in current computer and telecommunication industries for its large mass of data. Video segmentation and key-frame extraction have become crucial for the development of advanced digital video systems. Key frame extraction is a very useful technique to provide a concise access to the video content and is the first step towards efficient browsing and retrieval...
This paper explains and implements a fast image mosaic algorithm for unmanned aerial vehicle (UAV) sequence images. In this algorithm, feature points between images are matched using a modified Harris corner detection algorithm, and then an improved pyramid Lucas-Kanade optical flow algorithm and corner points matching authentication algorithm is used to achieve an effective match of the feature points...
In this paper, we propose multilevel framework for summarization of surveillance videos using motion entropy by maintaining chronology of activities. We aim to reduce the size of the video to give a meaningful summary by retaining important activities without destroying the temporal relationship of the activities. Initially input video is divided into blocks and then blocks into segments in a multilevel...
Analyzing the actions of humans by using cameras can be termed as Action Recognition. This concept of Action Recognition is now used in many fields, especially in the field of Robotics and intelligent systems in which there is a greater need for the recognition of the actions. Recognizing of humans and also their activity is very much important for any intelligent system, which is to be done intelligently...
Motion is one of the main characteristics that describe the semantic information of videos. In this work, a global video descriptor based on orientation tensors is proposed. This descriptor is obtained by combining polynomial coefficients calculated for each image in a video. The coefficients are found through the projection of the optical flow on Legendre polynomials, reducing the dimension of per...
Human actions are diversified and complicated, and hence difficult to be recognized by artificial intelligence systems. Recognizing actions in broadcast videos is even more challenging due to low resolution and frame rate. During the past decades, many talented researchers are devoted to this field, and several promising algorithms are developed to achieve great performance. The well known methods...
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