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Automatically recognising facial emotions has drawn increasing attention in computer vision. Facial landmark based methods are one of the most widely used approaches to perform this task. However, these approaches do not provide good performance. Thus, researchers usually tend to combine more information such as textural and audio information to increase the recognition rate. In this paper we propose...
Despite of having no explicit shape model, multi-atlas approaches to image segmentation have proved to be a top-performer for several diverse datasets and imaging modalities. In this paper, we show how one can directly incorporate shape regularization into the multi-atlas framework. Unlike traditional methods, our proposed approach does not rely on label fusion on the voxel level. Instead, each registered...
The analysis of human gait is more and more investigated due to its large panel of potential applications in various domains, like rehabilitation, deficiency diagnosis, surveillance and movement optimization. In addition, the release of depth sensors offers new opportunities to achieve gait analysis in a non-intrusive context. In this paper, we propose a gait analysis method from depth sequences by...
This paper presents a sparse representation based image inpainting method using local patch analysis and geometric structure based feature extraction. In local patch analysis, we approximate the target region by weighted average of some local patches which are frequently occurred within a neighborhood. Local patch statistics is applied to find the most relevant neighbors for each target patch. Further...
In this paper, we propose a new local descriptor for action recognition in depth images. The proposed descriptor relies on surface normals in 4D space of depth, time, spatial coordinates and higher-order partial derivatives of depth values along spatial coordinates. In order to classify actions, we follow the traditional Bag-of-words (BoW) approach, and propose two encoding methods termed Multi-Scale...
The particle size distribution (PSD) of a dispersed phase is a fundamental geometrical characteristic that needs to be determined from digital images for many industrial processes involving a multiphase flow. Nevertheless, when dealing with 2-D images, only the projections of the particles are visualized and therefore the particles can overlap each other. In this way, this paper aims to develop and...
A novel similarity-covariant feature detector that extracts points whose neighborhoods, when treated as a 3D intensity surface, have a saddle-like intensity profile. The saddle condition is verified efficiently by intensity comparisons on two concentric rings that must have exactly two dark-to-bright and two bright-to-dark transitions satisfying certain geometric constraints. Experiments show that...
The clustering algorithm by fast search and find of density peaks is shown to be a promising clustering approach. However, this algorithm involves manual selection of cluster centers, which is not convenient in practical applications. In this paper we discuss the correlation between density peaks and cluster centers. As a result, we present a new local density estimation method to highlight the uniqueness...
This paper presents a novel Robust Deep Appearance Models (RDAMs) approach to learn the non-linear correlation between shape and texture of face images. In this approach, two crucial components of face images, i.e. shape and texture, are represented by Deep Boltzmann Machines and Robust Deep Boltzmann Machines (RDBM), respectively. The RDBM, an alternative form of Robust Boltzmann Machines, can separate...
Existing distance metric learning methods define an objective function and seek a distance metric (or equivalently a projection) that minimizes it. In this paper, we propose a different approach that illustrates how to formulate distance metric learning as a regression problem. First, the objective function is minimized to learn target representations. Then, a regression method is employed to learn...
This paper addresses the problem of semantic overlap across document objects in the context of ground truth representation for document layout analysis. Document object categories often share primitives from a low-level perspective (e.g. regions inside bars in a bar chart resemble background), making it difficult to evaluate document layout segmentation methods based on pixel classification, as most...
The distance set is known to be a versatile local descriptor of shape. As this is simply a set of ordinary distances between sample points on a shape, it is easy to construct and use. More importantly, it remains invariant under many settings and deformations, unlike other typical descriptors. However, in shape matching with distance sets, there is a tradeoff between performance and computational...
Clinical studies have established the importance of morphologic measurements of intracranial aneurysm size, neck width, aspect ratio and other shape indices for the assessment of the risk of rupture and selection of the best treatment option. Obtaining these morphologic measurements requires segmentation of vascular structures in an angiographic image, reconstruction of a 3D vascular surface mesh,...
In recent years, with the explosion of digital images on the Web, content-based retrieval has emerged as a significant research area. Shapes, textures, edges and segments may play a key role in describing the content of an image. Radon and Gabor transforms are both powerful techniques that have been widely studied to extract shape-texture-based information. The combined Radon-Gabor features may be...
Level set-based contour tracking methods have generated recent interest in the computer vision community. In this paper, we propose a novel level set-based algorithm for tracking dynamic implicit contours that utilizes minimal prior information. Our solution consists of two main steps. In the first step, a simple first-order Markov chain model is employed for the coarse localization of a target object...
In the context of tree species recognition, botanists knowledge was used in different works specially when recognising tree species through leaves. In this paper, two sub-classification strategies for tree species recognition are proposed. For each sub-classification strategy, Basic belief assignment (Bba) was determined and obtained data were fused thanks to a totally adaptive fusion system implemented...
Gait recognition is nowadays an important biometric technique for video surveillance tasks, due to the advantage of using it at distance. However, when the upper body movements are unrelated to the natural dynamic of the gait, caused for example by carrying a bag or wearing a coat, the reported results show low accuracy. With the goal of solving this problem, we apply persistent homology to extract...
In this paper we propose a multi-modal object recognition system that uses a two-step hypothesis verification approach to improve runtime efficiency. The system uses local and global appearance and shape features, generating many possibly competing hypotheses, which are then verified such that the scene can be optimally explained in terms of recognized object models. The introduced modification in...
Face alignment is an important issue in many computer vision problems. The key problem is to find the nonlinear mapping from face image or feature to landmark locations. In this paper, we propose a novel cascaded approach with bidirectional Long Short Term Memory (LSTM) neural networks to approximate this nonlinear mapping. The cascaded structure is used to reduce the complexity of this problem and...
Active one-shot scanning techniques have been widely used for various applications. Stereo-based active one-shot scanning embeds a positional information regarding the image plane of a projector onto a projected pattern to retrieve correspondences entirely from a captured image. Many combinations of patterns and decoding algorithms for active one-shot scanning have been proposed. If the capturing...
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