基于GPU加速的光线跟踪渲染算法研究

分析了光线跟踪渲染算法在GPU上实现的流程;设计了CUDA平台上基于BVH加速结构的光线跟踪渲染引擎,针对CUDA架构的特点重新设计了BVH遍历算法和间接反射计算算法;并在四个场景和两种分辨率下针对GPU和CPU实现进行了详细对比测试。通过分析实验结果,基于GPU加速的光线跟踪算法在不同复杂度的场景下相比其CPU实现都有较高的性能提升。     

基于CUDA的高速并行均值滤波算法

分析了均值滤波算法的并行特性,提出了一种基于计算统一设备架构（CUDA）的均值滤波图形处理单元（GPU）并行算法。算法首先依据椒盐噪声的特征,建立信号点标记矩阵;其次计算信号密度,并确定滤波半径;最后仅处理噪声像素,用其邻城内信号点像素灰度的均值代替它。实验结果表明,随着图像尺寸的增大,该并行算法相比串行算法速度,可以获得300倍以上的加速比。     

Graphic processing unit-accelerated mutual information-based 3D image rigid registration

Mutual information (MI)-based image registration is effective in registering medical images, but it is computationally expensive. This paper accelerates MI-based image registration by dividing computation of mutual information into spatial transformation and histogram-based calculation, and performing 3D spatial transformation and trilinear interpolation on graphic processing unit (GPU). The 3D floating image is downloaded to GPU as flat 3D texture, and then fetched and interpolated for each new voxel location in fragment shader. The transformed results are rendered to textures by using frame buffer object (FBO) extension, and then read to the main memory used for the remaining computation on CPU. Experimental results show that GPU-accelerated method can achieve speedup about an order of magnitude with better registration result compared with the software implementation on a single-core CPU.     

应用GPU加速结合压缩传感技术解宽角度电磁散射问题

本文基于矩量法（MOM）中阻抗矩阵与入射角度的不相关性,提出将压缩传感（CS）技术引入电磁散射问题的方法,以达到在不降低计算精度的前提下减少计算时间的目的.该方法结合了压缩感知和计算统一设备架构（CUDA）技术,通过利用图形处理器（GPU）的并行计算解决了宽角度的电磁散射问题.数值计算结果表明,该方法与传统计算方法相比,在保持精度的同时,大大降低了计算所需的时间.     

基于GPU加速的扩频信号捕获方法

针对扩频信号捕获中计算量大和运算速度慢的问题,提出基于图形处理器(GPU)加速的捕获方法,将基于循环相关的捕获算法转化为计算统一设备架构(CUDA)线程块执行过程,使扩频捕获过程完全在GPU中加速执行,在保持原有扩频信号捕获概率的同时,显著提高了算法的运算速度. 实验结果表明,基于GPU的捕获方法有效地提高了系统的执行效率.     

基于GPU的HJ-1C实时成像处理技术

以HJ-1C卫星为研究对象,针对合成孔经雷达（SAR）卫星成像算法复杂,以及计算量大等特点,在研究GPU并行处理技术的基础上,给出GPU平台下针对HJ-1C地面快视系统的CS算法实现.经测试表明,SAR实时成像处理系统成像处理速度优于600 Mbps,能够满足地面接收系统对HJ-1C实时成像处理的要求.     

基于EFG法的GPU加速研究综述

无网格伽辽金法(Element-Free Galerkin Method,EFG法)是无网格法(Element-Free Method,EFM)的一种,随着有限元法在解决不连续问题和结构大变形问题,例如材料的相变、材料的破坏和失效以及冲击裂纹扩展等问题遇到瓶颈,EFG法在国内外被广泛研究与应用,大量的研究显示,EFG法在求解上述问题时具有独特的优势,但也存在计算量大的劣势,同时GPU在数据处理上优势明显,所以将GPU应用于EFG法加速一直是学术界研究的热点。     

血管分割可视化中的快速交互型渲染方法

Medical diagnosis software and computer-assisted surgical systems often use segmented image data to help clinicians make decisions. The segmentation extracts the region of interest from the background, which makes the visualization clearer. However, no segmentation method can guarantee accurate results under all circumstances. As a result, the clinicians need a solution that enables them to check and validate the segmentation accuracy as well as displaying the segmented area without ambiguities.With the method presented in this paper, the real CT or MR image is displayed within the segmented region and the segmented boundaries can be expanded or contracted interactively. By this way, the clinicians are able to check and validate the segmentation visually and make more reliable decisions. After experiments with real data from a hospital, the presented method is proved to be suitable for efficiently detecting segmentation errors. The new algorithm uses new graphic processing uint (GPU) shading functions recently introduced in graphic cards and is fast enough to interact on the segmented area, which was not possible with previous methods.     

GPU-based leaves contour generation algorithm

The implementation and optimization of the traditional contour generation algorithms are always proposed for the common processor. When processing high resolution images, the performance often exists low efficiency. A new graphics processing unit (GPU)-based algorithm is proposed to get the clear and integrated contour of leaves. Firstly we implement the classic Sobel operator of edge detection in GPU. Then a simple and effective method is designed to remove the fake edge and a heuristic algorithm is used to repair the broken edge. It is proved by the experiments that the results of our algorithm are natural and realistic in terms of morphology and can be good materials for the virtual plant.     

浅谈非线性编辑系统的发展和展望

本文介绍了非线性编辑技术,并根据非线性编辑系统的发展和组成,将非线性编辑系统分成三类,详细介绍了这三类非线性编辑系统,分析了这三类系统的优缺点,最后展望了非线性编辑系统的发展趋势。