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Fisheye cameras prove a convenient means in surveillance and automotive applications as they provide a very wide field of view for capturing their surroundings. Contrary to typical rectilinear imagery, however, fisheye video sequences follow a different mapping from the world coordinates to the image plane which is not considered in standard video processing techniques. In this paper, we present a...
In this paper, we propose a robust video colorization method automatically through limited color references in a video sequence. The proposed method first estimates motion vectors between a monochrome frame and colored reference frames for initial matching by optical flow. Then it transfers color information to matched points in the monochrome frame and further propagates color information of matched...
Recently, graph ranking-based methods have been introduced to visual tracking and achieved promising results due to the local structure preserving property. However, existing graph ranking-based trackers use holistic templates to construct the graphs which makes the trackers sensitive to occlusions. In this paper, we propose a part-based multi-graph ranking algorithm for robust visual tracking. In...
Fisheye cameras have become extremely popular in applications where the goal is to capture large fields of view with only one camera. However, the wide-angle fisheye imagery has special characteristics that may not be very well suited for modern video codecs that employ block-based translational motion model. This model fails to describe complex deformable motion which is often present in fisheye...
A compressed video quality assessment dataset based on the just noticeable difference (JND) model, called MCL-JCV, is recently constructed and released. In this work, we explain its design objectives, selected video content and subject test procedures. Then, we conduct statistical analysis on collected JND data. We compute the difference between every two adjacent JND points and propose an outlier...
Subjective studies showed that most HDR video tone mapping operators either produce disturbing temporal artifacts, or are limited in their local contrast reproduction capability. Recently, both these issues have been addressed by a novel temporally coherent local HDR tone mapping method, which has been shown, both qualitatively and through a subjective study, to be advantageous compared to previous...
To improve the rate-distortion (RD) performance of low delay (LD) High Efficiency Video Coding (HEVC) encoding while enabling scene-based non-linear editing feature (NLEF), in this paper, we present a new scene-based LD HEVC encoding framework in which scene change (SC) detection and coding are conducted jointly. A frame in a sequence to be encoded is deemed a SC if there is a sudden change in the...
The human brain is a complex and dynamic system. This paper quantifies how it responds to change in video quality through changes in the distribution of feature vectors extracted from high-resolution electroencephalograph (EEG) signals. Specifically, subjects watch test video sequences with and without degradation while their brain response is recorded using a 128-channel EEG system. Power band feature...
Network streaming video services have been growing explosively in the past decade, but how to measure and assure the video quality-of-experience (QoE) of end consumers is still an open problem. Poor presentation quality and playback stalling have been identified as the most dominant factors that degrade user QoE. Although both factors have been studied individually, little is known about the interactions...
In this paper we present a novel method for crowd behavior identification. In our method, the motion flow field is obtained from the video by computing the dense optical flow. Then, a thermal diffusion process (TDP) is exploited to increase the coherence of the motion flow. Approximating the moving particles to individuals, their interaction forces are computed using a modified variant of the social...
In this work, we propose a multi-view temporal video segmentation approach that employs a Gaussian scoring process for determining the best segmentation positions. By exploiting the semantic action information that the dense trajectories video description offers, this method can detect intra-shot actions as well, unlike shot boundary detection approaches. We compare the temporal segmentation results...
Spatio-temporal desynchronization remains a major challenge for watermarking system as it could impair the detection of the hidden payload. Over the years, several (non-blind) registration techniques have been proposed to realign the analyzed content prior to watermark detection and thereby achieve robustness against severe attacks such as display-and-camcord. Such techniques rely on assumptions that...
In many human activity recognition systems the size of the unlabeled training data may be significantly large due to expensive human effort required for data annotation. Moreover, the insufficient data collection process from heterogenous sources may cause dissimilarities between training and testing data. To address these limitations, a novel probabilistic approach that combines learning using privileged...
For the generation of overview panoramic images from aerial surveillance videos, registered video frames are stitched together. Assuming a planar landscape, feature points can be detected and used to estimate a homography. However, if the features are affected by radial distortion, their mapping depends on their position within the frame and the resulting homography becomes inaccurate. As a result,...
This paper presents a methodology to characterize information about groups of people with the main goal of detecting cultural aspects. Based on tracked pedestrians, groups are detected and characterized. Group information is then used to find out Cultural aspects in videos, based on the Hofstede cultural dimensions theory. The presented work was tested in videos of pedestrian groups recorded in different...
Increasing spatial resolution is often required in many applications such as entertainment systems or video surveillance. Apart from using higher resolution sensors, it is also possible to apply superresolution algorithms to realize an increased resolution. Those methods can be divided into approaches that rely on only a single low resolution image or on multiple low resolution video frames. While...
This paper proposes an effective Temporally Aligned Pooling Representation (TAPR) for video-based person re-identification. To extract the motion information from a sequence, we propose to track the superpixels of the lowest portions of human. To perform temporal alignment of videos, we propose to select the “best” walking cycle from the noisy motion information according to the intrinsic periodicity...
This paper presents a simple and efficient method for action recognition based on the learning of an explicit representation for an intrinsic dynamic shape manifold of human action. The proposed model relies on a short temporal set of FastMap dimensionality reduction-based technique for embedding a sequence of raw moving silhouettes, associated to an action video into a low-dimensional space, in order...
Video retrieval and video copy detection are well studied problems. The goal is to find the matching video in a database from a given query video. Typically, these query videos are short and aligning the query video is of secondary importance. Short sequences can be aligned using dynamic time warping. But, since time and memory usage increases quadratically with the length of the sequences, such process...
Super-resolution (SR) algorithms for video sequences with high resolution (HR) guide frames can provide outstanding performances. Non-local means (NLM) algorithm compares the similarity between a pixel and its neighbors. NLM replaces every pixel with a weighted average of its neighbors. The NLM based SR algorithm can super-resolve low resolution (LR) frames using the HR guide frames in the video sequence...
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