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We present a method to jointly refine the geometry and semantic segmentation of 3D surface meshes. Our method alternates between updating the shape and the semantic labels. In the geometry refinement step, the mesh is deformed with variational energy minimization, such that it simultaneously maximizes photo-consistency and the compatibility of the semantic segmentations across a set of calibrated...
How much does a single image reveal about the environment it was taken in? In this paper, we investigate how much of that information can be retrieved from a foreground object, combined with the background (i.e. the visible part of the environment). Assuming it is not perfectly diffuse, the foreground object acts as a complexly shaped andfar-from-perfect mirror An additional challenge is that its...
While hand geometry trait has been widely used to perform biometric recognition, majority of the methods employ images acquired against a uniform background. If segmentation of the hand is implemented, existing techniques can be used in cluttered backgrounds as well. This paper presents an approach for accurate segmentation of human hands for images following the aforementioned conditions using skin...
A major challenge in visual highway traffic analytics is to disaggregate individual vehicles from clusters formed in dense traffic conditions. Here we introduce a data driven 3D generative reasoning method to tackle this segmentation problem. The method is comprised of offline (learning) and online (inference) stages. In the offline stage, we fit a mixture model for the prior distribution of vehicle...
Texture is an important feature in RS image classification of land-use, and its precision mainly depends on the scale parameters, which are strongly correlated with the geometry characteristics of the classified objects. However, there is no a recognized reliable method for texture scale extraction. So this paper proposes an new approach to indirectly extract them with the assistance of domain GIS...
A novel method for the detection and segmentation of nuclei and cells in Pap smear images is introduced. The method is based on a geometric analysis of iso- and edge-contours. For nuclei detection we employ isocontours taken at different levels of intensity and we report best detection (object) recall values as well as best segmentation precision values. For cell outline detection, we employ traditional...
The consideration of meaningful geographical objects instead of individual pixels is the main distinguishing characteristic of Geographic Object-Based Image Analysis (GEOBIA) methods. In this regard, meaningful geographical objects enable image analysis methods to consider extra information, such as geometry, texture and spatial relationships to analyse imagery. However, meaningful geographical objects...
Research on hand gesture recognition has been intensified in the last decade. There has been successful work on gesture recognition by using shape and texture features from 2D images and videos. However, it is still a challenging task in handling various conditions with hand scale variations, hand rotations, and hand ambiguity due to finger occlusions. Recent work has started using depth images for...
As robots begin to collaborate with humans in everyday workspaces, they will need to understand the functions of tools and their parts. To cut an apple or hammer a nail, robots need to not just know the tool's name, but they must localize the tool's parts and identify their functions. Intuitively, the geometry of a part is closely related to its possible functions, or its affordances. Therefore, we...
An accurate algorithm for 3D rib reconstruction of an individual patient is presented. Segmented ribs are reconstructed in a cylindrical coordinate system, based on available knowledge of human rib geometry. Each rib is reconstructed individually using data from multidetector computed tomography (MDCT) images, which provides geometrical data including unique angle, length, curvature and mass. The...
In this paper it is presented a simulation analysis of electric fields generated by lightning channels with tortuosity. The tortuosity of the channel is reproduced by means of a numerical algorithm that takes into account statistical characterizations made by different authors observing real lightning channels, so the macroscale tortuosity of the simulated channel is similar to the one recorded in...
In this paper, we present a new method to establish quasi-dense correspondence between a pair of stereo images without camera calibration. Our proposed method is based on the traditional snake formulation using an energy function. The energy function incorporates a new matching term. When the energy function is minimized, the control points along the curves in a stereo pair are matched. Moreover,...
This paper presents a method for learning 3D object templates from view labeled object images. The 3D template is defined in a joint appearance and geometry space composed of deformable planar part templates placed at different 3D positions and orientations. Appearance of each part template is represented by Gabor filters, which are hierarchically grouped into line segments and geometric shapes. AND-OR...
This paper presents a novel local feature for 3D range image data called ‘the line image’. It is designed to be highly viewpoint invariant by exploiting the range image to efficiently detect 3D occupancy, producing a representation of the surface, occlusions and empty spaces. We also propose a strategy for defining keypoints with stable orientations which define regions of interest in the scan for...
The left ventricular (LV) shape alteration is believed that has close correlation with cardiac disease and LV regional function. In this paper, we propose a set of procedure to evaluate LV shape deformation quantitatively and precisely. The LV myocardial shape of first cardiac cycle (end diastole) is reconstructed using a set of control points manually by expert and then tracked to last cardiac cycle...
Cerebral aneurysm is a weak spot in a blood vessel that usually enlarges. Nowadays, cerebral aneurysm detection method is still being done manually by visually observing 2D or 3D medical images (CTA). The main purpose of this paper is to design a method of cerebral aneurysm detection and classify different vascular geometry with color indicator. The method developed was based on curvature analysis...
First, the advantages of using "Geometer's sketchpad" to teach middle school mathematics thinking has been discussed in this essay. It also has demonstrated several basical mathematic method, such as deductive inference and Axiomatic thought method, combination of figure and shape, classified discussion thought method, transformation and reduction thought method, Comparison and analogy thought...
This paper presents a contactless hand based biometric identification system using geometric and palm features. Hand images are acquired using two commercial webcams with 1200×1600 pixel resolution which are refered to as the “IR” and “visible” webcams. The IR webcam has been modified by exchanging the IR filter with a visible filter lens and reducing the gain and exposure time to improve the hand...
In the context of vessel tree structures segmentation with implicit deformable models, we propose to exploit convolution surfaces to introduce a novel variational formulation, robust to bifurcations, tangential vessels and aneurysms. Vessels are represented by an implicit function resulting from the convolution of the centerlines of the vessels, modeled as a second implicit function, with localized...
The objective of the present study is to develop an automatic tool to identify and classify the different types of cocci bacterial cells in digital microscopic cell images using active contour method. Snakes, or active contours, are used extensively in computer vision and image processing applications, particularly to locate object boundaries. Geometric features are used to identify the arrangement...
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