Search results for " Graphics"

Characterization of the 3D information of Calyptogena shells

2003

We propose in this paper an application of multiresolution analysis techniques to extract information contained in the growth increments of a bivalve mollusk called: Calyptogena . The first stage consists in extracting a range image of the mollusk’s shell using a 3-D scanner. Applying a multiresolution analysis enables us to localize precisely those growth increments by preserving relevant details. Moreover, interesting spatial and frequency properties of the multiresolution analysis underline information contained on the shell. Intra-individual variation and inter-individual variations are compared to assume some conclusions as for the ontogenetic evolution of the animal such as periodicit…

How to best return the value of a function

1989

Accelerating H.264 inter prediction in a GPU by using CUDA

2010

H.264/AVC defines a very efficient algorithm for the inter prediction but it takes too much time. With the emergence of General Purpose Graphics Processing Units (GPGPU), a new door has been opened to support this video algorithm into these small processing units. In this paper, a forward step is developed towards an implementation of the H.264/AVC inter prediction algorithm into a GPU using Compute Unified Device Architecture (CUDA). The results show a negligible rate distortion drop with a time reduction on average up to 93.6%.

Orders of Consciousness and Forms of Reflexivity in Descartes

2007

Regularization operators for natural images based on nonlinear perception models.

2006

Image restoration requires some a priori knowledge of the solution. Some of the conventional regularization techniques are based on the estimation of the power spectrum density. Simple statistical models for spectral estimation just take into account second-order relations between the pixels of the image. However, natural images exhibit additional features, such as particular relationships between local Fourier or wavelet transform coefficients. Biological visual systems have evolved to capture these relations. We propose the use of this biological behavior to build regularization operators as an alternative to simple statistical models. The results suggest that if the penalty operator take…

The finite element implementation of 3D fractional viscoelastic constitutive models

2018

Abstract The aim of this paper is to present the implementation of 3D fractional viscoelastic constitutive theory presented in Alotta et al., 2016 [1]. Fractional viscoelastic models exactly reproduce the time dependent behaviour of real viscoelastic materials which exhibit a long “fading memory”. From an implementation point of view, this feature implies storing the stress/strain history throughout the simulations which may require a large amount of memory. We propose here a number of strategies to effectively limit the memory required. The form of the constitutive equations are summarized and the finite element implementation in a Newton-Raphson integration scheme is described in detail. …

Visual motion integration controls attractiveness of objects in walking flies and a mobile robot

2008

Walking fruit flies are attracted by near-by objects. They estimate the distance to these objects by the parallax motion of their images on the retina. Here we provide evidence from robot simulations that distance is assessed by motion integration over large parts of the visual field and time periods of 0.5 s to 2 s. The process in flies is not selective to image motion created by the self-motion of the fly but also sensitive to object motion and to the pattern contrast of objects. Added visual motion (e.g. oscillations) makes objects more attractive than their stationary counterparts. Front-to-back motion, the natural parallax motion on the eyes of a forward-translating fly, is preferred. …

A reverse engineering approach to measure the deformations of a sailing yacht

2016

In this work, a multidisciplinary experience, aimed to study the permanent deformations of the hull of a regatta sailing yacht is described. In particular, a procedure to compare two different surfaces of the hull of a small sailing yacht, designed and manufactured at the University of Palermo, has been developed. The first one represents the original CAD model while the second one has been obtained by means of a reverse engineering approach. The reverse engineering process was performed through an automatic close-range photogrammetry survey, that has allowed to obtain very accurate measures of the hull, and a 3D modelling step by the well-known 3D computer graphics software Rhinoceros. The…

Rotation-Invariant Texture Retrieval via Signature Alignment Based on Steerable Sub-Gaussian Modeling

2008

This paper addresses the construction of a novel efficient rotation-invariant texture retrieval method that is based on the alignment in angle of signatures obtained via a steerable sub-Gaussian model. In our proposed scheme, we first construct a steerable multivariate sub-Gaussian model, where the fractional lower-order moments of a given image are associated with those of its rotated versions. The feature extraction step consists of estimating the so-called covariations between the orientation subbands of the corresponding steerable pyramid at the same or at adjacent decomposition levels and building an appropriate signature that can be rotated directly without the need of rotating the im…

Cost-Efficient On-Chip Routing Implementations for CMP and MPSoC Systems

2011

[EN] The high-performance computing domain is enriching with the inclusion of networks-on-chip (NoCs) as a key component of many-core (CMPs or MPSoCs) architectures. NoCs face the communication scalability challenge while meeting tight power, area, and latency constraints. Designers must address new challenges that were not present before. Defective components, the enhancement of application-level parallelism, or power-aware techniques may break topology regularity, thus, efficient routing becomes a challenge. This paper presents universal logic-based distributed routing (uLBDR), an efficient logic-based mechanism that adapts to any irregular topology derived from 2-D meshes, instead of usi…