Search results for "Graphics"
showing 10 items of 1223 documents
Optical See-Through Head-Mounted Displays With Short Focal Distance: Conditions for Mitigating Parallax-Related Registration Error
2020
Optical see-through (OST) augmented reality head-mounted displays are quickly emerging as a key asset in several application fields but their ability to profitably assist high precision activities in the peripersonal space is still sub-optimal due to the calibration procedure required to properly model the user's viewpoint through the see-through display. In this work, we demonstrate the beneficial impact, on the parallax-related AR misregistration, of the use of optical see-through displays whose optical engines collimate the computer-generated image at a depth close to the fixation point of the user in the peripersonal space. To estimate the projection parameters of the OST display for a …
An Online Observer for Minimization of Pulsating Torque in SMPM Motors.
2015
A persistent problem of surface mounted permanent magnet (SMPM) motors is the non-uniformity of the developed torque. Either the motor design or the motor control needs to be improved in order to minimize the periodic disturbances. This paper proposes a new control technique for reducing periodic disturbances in permanent magnet (PM) electro-mechanical actuators, by advancing a new observer/estimator paradigm. A recursive estimation algorithm is implemented for online control. The compensating signal is identified and added as feedback to the control signal of the servo motor. Compensation is evaluated for different values of the input signal, to show robustness of the proposed method.
Mesh Visual Quality Assessment Metrics: A Comparison Study
2017
3D graphics technologies have known a developed progress in the last years, and several processing operations can be applied on 3D meshes such as watermarking, compression, simplification and so forth. Mesh visual quality assessment becomes an important issue to evaluate the visual appearance of the 3D shape after specific modifications. Several metrics have been proposed in this context, from the classical distance-based metrics to the perceptual-based metrics which include perceptual information about the human visual system. In this paper, we propose to study the performance of several mesh visual quality metrics. First, the comparison is conducted regardless the distortion types neither…
Don’t miss your train! Just follow the computer screen animation: Comprehension of animated public information graphics
2014
Computer graphic animated information displays have the potential to communicate public information in situations where normal announcement types are ineffective. This study used eye tracking techniques to analyze comprehension mechanism of event-related information on railway traffic disruptions presented via different graphic formats presented on computer screen. 86 participants were asked to understand series of traffic disruption messages delivered via four purely visual formats: Static simultaneous, Static sequential, Animated simultaneous and Animated sequential. Across these four conditions, and contrary to the most common materials used in the studies on animation comprehension, the…
Artificial mosaics
2005
Art often provides valuable insight that can be applied to technological innovations, especially in the fields of image processing and computer graphics. In this paper we present a method to transform a raster input image into a good-quality mosaic: an “artificial mosaic.” The creation of mosaics of artistic quality is challenging because the tiles that compose a mosaic, typically small polygons, must be packed tightly and yet must follow and emphasize orientations chosen by the artist. The proposed method can reproduce the colors of the original image and emphasize relevant boundaries by placing tiles along edge directions. No user intervention is needed to detect the boundaries: they are …
Stochastic Tension-Stiffening Approach for the Solution of Serviceability Problems in Reinforced Concrete: Constitutive Modeling
2015
A number of studies have indicated that the tension-stiffening law is an important input parameter in a numerical analysis of serviceability (deformations and cracking) problems of reinforced concrete (RC) structures. The stochastic nature of concrete cracking, which results in a large scatter of experimental results, renders the constitutive modeling a very difficult task. Even data obtained from short-term tests are to some degree uncertain due to time-dependent processes occurring in concrete, such as shrinkage and creep relaxation. This article provides statistical analysis tools that can be readily applied to engineering practice. Stochastic principles are applied to modeling of tensio…
Visualization1.mov
2019
movie of the recorded set of single shot slightly off-axis holograms
Visualization1.mov
2019
movie of the recorded set of single shot slightly off-axis holograms
Addressing the Occlusion Problem in Augmented Reality Environments with Phantom Hollow Objects
2018
Occlusion handling is essential to provide a seamless integration of virtual and real objects in AR applications. Different approaches have been presented with a variety of technologies, environment conditions and methods. Among these methods, 3D model-based occlusion approaches have been extensively used. However, these solutions could be too time-consuming in certain situations, since they must render all the occlusion objects even though they are invisible. For this reason, we propose an inverse 3D model-based solution for handling occlusions, designed for those AR applications in which virtual objects are placed inside a real object with holes or windows. With this restriction, the occl…
Mixed-aspect fractal surfaces
2013
In order to provide accurate tools to model original surfaces in a Computer Aided Geometric Design context, we develop a formalism based on iterated function systems. This model enables us to represent both smooth and fractal free-form curves and surfaces. But, because of the self-similarity property underlying the iterated function systems, curves and surfaces can only have homogeneous roughness. The aim of our work was to elaborate a method to build parametric shapes (curves, surfaces, ...) with a non-uniform local aspect: every point is assigned a ''geometric texture'' that evolves continuously from a smooth to a rough aspect. The principle is to blend shapes with uniform aspects to defi…