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Person reidentification is a problem of recognizing a person across non-overlapping camera views. Pose variations, illumination conditions, low resolution images, and occlusion are the main challenges encountered in reidentification. Due to the uncontrolled environment in which the videos are captured, people could appear in different poses and due to which the appearance of a person could vary significantly...
Matching specific persons across scenes, known as person re-identification, is an important yet unsolved computer vision problem. Feature representation and metric learning are two fundamental factors in person re-identification. However, current person re-identification methods, which use single handcrafted feature with corresponding metric, could be not powerful enough when facing illumination,...
Associating groups of people across non-overlapping camera views is an important but unsolved problem. Compared with the similar person re-identification task, group re-identification introduces some new challenges, such as significant deformation in uncontrolled directions, great intra-group occlusions and so on. In this paper, we propose a novel patch matching based framework for group re-identification...
The emergence of UHD video format induces larger screens and involves a wider stimulated visual angle. Therefore, its effect on visual attention can be questioned since it can impact quality assessment, metrics but also the whole chain of video processing and creation. Moreover, changes in visual attention from different viewing conditions challenge visual attention models. In this paper, we present...
When applying a filter to an image, it often makes practical sense to maintain the local brightness level from input to output image. This is achieved by normalizing the filter coefficients so that they sum to one. This concept is generally taken for granted, but is particularly important where nonlinear filters such as the bilateral or and non-local means are concerned, where the effect on local...
Subjective experimental results are widely used as the ground truth in objective Image Quality Assessment (IQA). Specifically, Pairwise Comparison method has superiority over Mean Opinion Scores (MOS), but there is a problem when measuring the consistency between subjective pairwise comparisons and objective quality predictions. In this paper, we first analyze the existing problem of current evaluation...
In this paper, we propose a novel reduced-reference quality assessment metric for image super-resolution (RRIQA-SR) based on the low-resolution (LR) image information. First, we use the Markov Random Field (MRF) to model the pixel correspondence between LR and high-resolution (HR) images. Based on the pixel correspondence, we predict the perceptual similarity between image patches of LR and HR images...
Metric learning is an effective method for person re-identification. It utilizes latent factors to find a suitable space for measuring distances. In general, a small number of factors are not powerful enough to match the pedestrians while a large number of factors cause high computational cost. In this paper, to balance this trade-off, a novel diversity regularized distance metric learning method...
A local feature descriptor for image analysis is a tool of interest for many applications. In this paper we propose an in context feature descriptor. An instance of this descriptor corresponding to a specific feature includes information from all other features in the image; it is a feature in context descriptor. This descriptor is thus unique for a feature in an ensemble of features. Many medical...
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...
The goal of this paper is to investigate the effect of choosing a certain halftone screen on image graininess development and to establish the metrics for image graininess in high-end digital printing technologies. With the obtained knowledge, our model helps us choose the optimal periodicity matrices for designing regular or irregular clustered dot halftones. The main advantage of the proposed model...
In this paper we propose a new method to automatically select the rank of linear transforms during supervised learning. Our approach relies on a sparsity-enforcing element-wise soft-thresholding operation applied after the linear transform. This novel approach to supervised rank learning has the important advantage that it is very simple to implement and incurs no extra complexity relative to linear...
This paper investigates the discriminative capabilities of facial action units (AUs) exhibited by an individual while performing a task on a tablet computer in a semi-unconstrained environment. To that end, AUs are measured on a frame-by-frame basis from videos of 96 different subjects participating in a game-show-like quiz game that included a prize incentive. We propose a method that leverages the...
This paper proposes a new temporal consistency measure for quality assessment of synthesized video. Disocclusion regions appear hole regions of the synthesized video at virtual viewpoints. Filling hole regions could be problematic when the synthesized video is perceived through multi-view displays. In particular, the temporal inconsistency caused by hole filling process in view synthesis could affect...
We present COVERAGE — a novel database containing copy-move forged images and their originals with similar but genuine objects. COVERAGE is designed to highlight and address tamper detection ambiguity of popular methods, caused by self-similarity within natural images. In COVERAGE, forged-original pairs are annotated with (i) the duplicated and forged region masks, and (ii) the tampering factor/similarity...
The models based on deep convolutional networks and recurrent neural networks have dominated in recent image caption generation tasks. Performance and complexity are still eternal topic. Inspired by recent work, by combining the advantages of simple RNN and LSTM, we present a novel parallel-fusion RNN-LSTM architecture, which obtains better results than a dominated one and improves the efficiency...
The problem of person re-identification, identifying the same person appeared in different camera views, is an important and challenging task in computer vision that has high potential application in areas like visual surveillance. In this paper we introduce a new feature fusion strategy for person reidentification that combines low-level Weighted Histograms of Overlapping Stripes (WHOS) features...
We propose a method for detecting obstacles by comparing input and reference train frontal view camera images. In the field of obstacle detection, most methods employ a machine learning approach, so they can only detect pre-trained classes, such as pedestrian, bicycle, etc. This means that obstacles of unknown classes cannot be detected. To overcome this problem, we propose a background subtraction...
Catadioptric cameras developed recently provide images with large field of view. Nevertheless, due to the use of mirrors, these images contain significant radial distortions that are necessary to handle when processing them. In this paper, we present the use of differential geometry for the construction of a hybrid structure tensor suited to the multicomponent catadioptric images. This structure tensor...
Most of the existing works on person re-identification have focused on improving matching rate at top ranks. Few efforts are devoted to address the problem of efficient storage and fast search for person re-identification. In this paper, we investigate the prevailing hashing method, originally designed for large scale image retrieval, for fast person re-identification with efficient storage. We propose...
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