high performance computing on graphics processing units: hgpu.org

Graphics Processing Units (GPUs) are workhorses of modern performance due to their ability to achieve massive speedups on parallel applications. The massive number of threads that can be run concurrently on these systems allow applications which have data-parallel computations to achieve better performance when compared to traditional CPU systems. However, the GPU is not perfect […]

A large number of Fortran legacy programs are still running in production environments, and most of these applications are running sequentially. Multi- and Many- core architectures are established as (almost) the only processing hardware available, and new programming techniques that take advantage of these architectures are necessary. In this report, we will explore the impact […]

Segmentation of CT-Angiography datasets is an important and difficult task. Several algorithms and approaches have already been invented and implemented to solve this problem. In this work, we present automatic algorithms for the segmentation of these CTA datasets, implemented in CUDA, and evaluate our results regarding speed and error rates. Starting with local approaches like […]

In recent years, there has been a drive towards parallel architectures to further increase computational performance. The many-core architecture of modern Graphics Processing Units (GPU) can be used for general computations in addition to graphics processing, and provide good performance for data parallel computations. In this thesis, we explore the processing powers of two generations […]

A silhouette gives an outline of a person or an object. When extracting silhouettes from an image or video, we acquire information about where in the image the foreground objects are located, their sizes and their shapes. This silhouette information can be useful in many ways. In computer vision, silhouette extraction plays an important role. […]

Modern graphical processing units (GPU) are powerful parallel processors, capable of running thousands of concurrent threads. While originally limited to graphics processing, newer generations can be used for general computing (GPGPU). Through frameworks such as nVidia Compute Unified Device Architecture (CUDA) and OpenCL, GPU programs can be written using established programming languages (with minor extensions) […]

In this paper we present a digital holographic microscope to track gold colloids in three dimensions. We report observations of 100nm gold particles in motion in water. The expected signal and the chosen method of reconstruction are described. We also discuss about how to implement the numerical calculation to reach real-time 3D tracking.

In this paper, we enable interactive volumetric global illumination by extending photon mapping techniques to handle interactive transfer function (TF) and material editing in the context of volume rendering. We propose novel algorithms and data structures for finding and evaluating parts of a scene affected by these parameter changes, and thus support efficient updates of […]

Grain-128 is a stream cipher, which was proposed in the course of the eSTREAM project. This stream cipher is already in use today, for example in RFID applications. Therefore, the security of Grain-128 is of great interest. The Conditional Differential Analysis, the Static Cube Attack and the Dynamic Cube Attack are methods for the cryptanalysis […]

In this paper we explore a parallel implementation for fast calculation of a tomographic projection operator for content-adaptive mesh model (CAMM) image reconstruction. Previously we introduced 2D and 3D tomographic image reconstruction using a CAMM for single positron emission computed tomography (SPECT). The proposed parallel method is fast and allows incorporation of a non-uniform attenuation […]

We propose a new model for the improved reconstruction and zooming of JPEG (Joint Photographic Experts Group) images. In the reconstruction process, given a JPEG compressed image, our method first determines the set of possible source images and then specifically chooses one of these source images satisfying additional regularity properties. This is realized by employing […]

A Lagrangian particle scheme is applied to the projection method for the incompressible Navier-Stokes equations. The approximation of spatial derivatives is obtained by a computationally expensive Finite Pointset method. GPU computations are applied to improve the computational speed-up. The numerical solutions are obtained for the broken dam problem and are compared with the analytical solutions. […]