多维传输函数技术研究及医学图像体视化系统设计与实现
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摘要
医学图像可视化是当前一个研究热点问题,它将计算机图形学和图像处理技术运用在生物医学工程中,在医学诊断、手术规划及模拟仿真等都方面都有着广泛的应用。体绘制技术已经成为医学图像可视化的重要方法。
传输函数设计是体绘制算法中的关键步骤,它能突出显示体数据中人们感兴趣的特征。本文分析了传统一维传输函数难以提取复杂的特征,实现了基于灰度—梯度模直方图传输函数。针对灰度—梯度模直方图传输函数受噪声影响大和固定大小梯度计算的问题,设计将局部体素三维矩的特征值作为定义域的传输函数,该方法将体数据的局部形状特征引入传输函数设计。本文运用LH(Lower and High Intensity)来表示形成边界体素的两种物质,设计了将体素的LH值投射到直方图传输函数,LH直方图传输函数解决了灰度一梯度直方图传输函数当弧线相交时边界选取问题,实验表明使用LH直方图比现有得方法更有利于物质边界得选择。镜像LH直方图将边界分为两部分,而镜像LH直方图解决了物质边界归属问题,能够形成更清晰和准确的物质边界。
本文提出了基于三切面和绘制空间的局部传输函数的设计,该方法有效的利用空间有效的解决了感兴趣区域和周围不感兴趣区域体数据值重叠的问题。
本文还讨论和实现了基于硬件加速的二维和三维纹理体绘制算法,大大的提高体绘制的速度。三维纹理硬件技术算法有较好的绘制效果和达到实时交互的绘制能力。最后,本文实现了一个基于上述原理和方法的医学体视化系统,获得了良好的体绘制效果。
Visualization on medical images is a hot spot field. It is an important application of computer graphics and image processing in biomedicine engineering. Visualization of medical images is widely used in diagnostic, surgery planning and simulating. Direct Volume Rendering is one of the most important techniques for visualizing medical volume data.
Transfer function specification is arguably the most important task in volume visualization that will highlight those aspects of the volume data that are of interest to the user. As the traditional transfer function is difficult to extract the complex feature, this thesis implements a multidimensional transfer function base on the scalar value and the gradient magnitude. For this method is involved the problem of the noise impact and fixed size of the gradient calculation, a transfer function base local data features design method is presented in this thesis ,by examining relationships among three eigenvalues of inertia matrix.
In this thesis, the two materials that form the boundary are labeled L and H. We design and implement a transfer function based on the LH histogram. The experiments tell that the LH transfer function is easy to select the boundaries while arches could be overlap in scalar value and gradient magnitude histogram. In mirrored LH space both sides of boundary can be classified independently.
This thesis introduce two local transfer functions, their fields are users interactive selected in three sections or rendering space. They can easily isolate the regions of interesting while uninteresting regions contain the same range of data value.
Finally, a medical image volume rendering system, which is based on texture-based hardware accelerated volume rendering technique, is designed and implemented with excellent result.
传输函数设计是体绘制算法中的关键步骤,它能突出显示体数据中人们感兴趣的特征。本文分析了传统一维传输函数难以提取复杂的特征,实现了基于灰度—梯度模直方图传输函数。针对灰度—梯度模直方图传输函数受噪声影响大和固定大小梯度计算的问题,设计将局部体素三维矩的特征值作为定义域的传输函数,该方法将体数据的局部形状特征引入传输函数设计。本文运用LH(Lower and High Intensity)来表示形成边界体素的两种物质,设计了将体素的LH值投射到直方图传输函数,LH直方图传输函数解决了灰度一梯度直方图传输函数当弧线相交时边界选取问题,实验表明使用LH直方图比现有得方法更有利于物质边界得选择。镜像LH直方图将边界分为两部分,而镜像LH直方图解决了物质边界归属问题,能够形成更清晰和准确的物质边界。
本文提出了基于三切面和绘制空间的局部传输函数的设计,该方法有效的利用空间有效的解决了感兴趣区域和周围不感兴趣区域体数据值重叠的问题。
本文还讨论和实现了基于硬件加速的二维和三维纹理体绘制算法,大大的提高体绘制的速度。三维纹理硬件技术算法有较好的绘制效果和达到实时交互的绘制能力。最后,本文实现了一个基于上述原理和方法的医学体视化系统,获得了良好的体绘制效果。
Visualization on medical images is a hot spot field. It is an important application of computer graphics and image processing in biomedicine engineering. Visualization of medical images is widely used in diagnostic, surgery planning and simulating. Direct Volume Rendering is one of the most important techniques for visualizing medical volume data.
Transfer function specification is arguably the most important task in volume visualization that will highlight those aspects of the volume data that are of interest to the user. As the traditional transfer function is difficult to extract the complex feature, this thesis implements a multidimensional transfer function base on the scalar value and the gradient magnitude. For this method is involved the problem of the noise impact and fixed size of the gradient calculation, a transfer function base local data features design method is presented in this thesis ,by examining relationships among three eigenvalues of inertia matrix.
In this thesis, the two materials that form the boundary are labeled L and H. We design and implement a transfer function based on the LH histogram. The experiments tell that the LH transfer function is easy to select the boundaries while arches could be overlap in scalar value and gradient magnitude histogram. In mirrored LH space both sides of boundary can be classified independently.
This thesis introduce two local transfer functions, their fields are users interactive selected in three sections or rendering space. They can easily isolate the regions of interesting while uninteresting regions contain the same range of data value.
Finally, a medical image volume rendering system, which is based on texture-based hardware accelerated volume rendering technique, is designed and implemented with excellent result.
引文
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[3]Lorensen W E,Cline H E.Marching Cubes:A High Resolution 3D Surface Construction Algorithm[J].Computer Graphics,1987,21(4),163-169.
[4]Levoy M.Display of Surface from Volume Data[J].IEEE Computer Graphics and Applications,1988,8(3):29-37.
[5]H.Pfister,B.Lorensen,et al.The transfer function bake-off[J].IEEE Computer Graphics and Applications,2001,21(3):16-22.
[6]G.Kindlmann,J.W.Durkin.Semi-automatic generation of transfer functions for direct volume rendering[A].Proceedings of IEEE Symposium On Volume Visualization[C],Research Triangle Park,North Carolina,1998,79-86.
[7]Drebin R.A.,Carpenter L.,and Hanrahan P.Volume rendering[A].In Proc.of SIGGRAPH'88[C],1988,65-74.
[8]管伟光.体视化技术及其应用[M].北京:电子工业出版社,1998.
[9]Oppenheim A.V.and Schafer R.W.Digital Signal Processing[M].Prentice Hall,Englewood Cliffs,1975.
[10]Max N.Optical Models for Direct Volume Rendering[J].IEEE Transactions on Visualization and Computer Graphics,1995,1(2):99-108.
[11]Levoy M.Volume Rendering by Adaptive Refinement[R].UNC Technical Report 88030,1988-7.
[12]Blinn J.F.Jim blinn's Comer:Image Compositing-theory[J].IEEE Computer Graphics and Applications,1994,14(5).
[13]Wittenbrink C.M.,Malzbender T.,and.Goss M.E.Opacity-weighted color interpolation for volume sampling[A].In Proc.of IEEE Symposium on Volume Visualization[C],1998,135-142.
[14]Porter T,Compositing Digital Images[J],Computer Graphics,1984,18(3):253-259
[15] Levoy M. Efficient Ray Tracing of Volume Data[J]. ACM Transactions on Graphics,1990,9(3): 245-261
[16] J. Kniss, G.. Kindlmann, C. Hansen. Multi-dimensional transfer functions for interactive volume rendering[J], IEEE Transactions on Visualization and Computer Graphics, 2002,8(3): 270-285.
[17] J. Kniss, G Kindlmann, C. Hansen. Interactive volume rendering using multi-dimensional transfer functions and direct manipulation widgets[A]. In: Proceedings of IEEE Visualization 2001 conference[C], San Diego, California, 2001, 255-262.
[18] Hladuvka, A.H.Konig, E.M.Goller. Curvature-based transfer functions for direct volume rendering[A]. In: Proceedings of Spring Conference and Computer Craphics(SCCG)[C],Budmerice, Slovakia, 2000,58-65.
[19] A. H. Konig, E. M. Groller. Mastering transfer function specification by using VolumePro technology[A]. In: Proceedings of Spring Conference on Computer Graphics(SCCG)[C],Budmerice, Slovakia, 2001,279-286.
[20] T. He, L.Hong, A.Kaufman, H.Pfister. Generation of transfer functions with stochastic search techniques[A]. In: Proceedings of IEEE Visualization 96 conference[C], San Francisco,California, 1996.227-234.
[21] J. Marks, B.Andalman, et al. Design Galleries: a general approach to setting parameters for computer graphics and animation[A]. In: Computer Graphics Proceedings, Annual Conference Series, ACM SIGGRAPH[C], Los Angeles, California, 1997, 38-400.
[22] C. L. Bajaj, V.Pascucci, D.R.Schikore. The contour spectrum[A]. In: Proceedings of IEEE Visualization 97 conference[C], Phoenix, Arizona, 1997, 167-173.
[23] V.Pekar, R. Wiemker, D.Hempel. Fast detection of meaningful isosurfaces for volume data visualization[A]. In: Proceedings of IEEE Visualization 2001[C], San Diego, California,2001.223-230.
[24] I. Fujishiro, T.Azuma, Y.Takeshima. Automating transfer function design for comprehensible volume rendering based on 3D field topology analysis[A]. In: Proceedings of IEEE Visualization 99 conference[C], San Francisco, California, 1999, 467-470.
[25] S. Tenginakai, L.Jinho, R.Machiraju. Salient iso-surface detection with model-independent statistical signatures[A]. In: Proceedings of IEEE Visualization 2001 conference[C], San Diego,California,2001.231-238.
[26]马颂德,张正友.计算机视觉-计算理论与算法基础[M].北京:科学出版社,1998.
[27]C.Lundstr(o|¨)m,A.Ynnerman,P.Ljung,A.Persson,and H.Knutsson.The α-histogram:Using spatial coherence to enhance histograms and transfer function design[A].In Proceedings IEEE/EuroGraphics Symposium on Visualization[C],2006,227-234.
[28]Granino A.Korn and Teresa M.Korn.Mathematical Handbook for Scientists and Engineers[M].New York:McGraw-Hill,1968,page 820.
[29]G.Lohmann,Volume image analysis[M],New York:John Wiley & Sons and B.G.Tuehner,1998.
[30]Atushi Imiya,Learning dimensionality and orientations of 3D objects[J],Pattern Recognition Letters,2001,Vol.22:75-83.
[31]Sereda P,Vilanova A,Serlie I,Gerritsen F.Visualization of boundaries in volumetric datasets using LH histograms[J].IEEE Transactions on Visualization and Computer Graphics,2006.
[32]H.W.Shen,C.Hansen,Y.Livnat,and C.R.Johnson.Isosurfacing in Span Space with utmost efficiency(ISSUE)[A].Proceedings IEEE Visualization[C],1996,287-294.
[33]孔明明 基于GPU集群的并行体绘制[D]浙江:浙江大学2007.
[34]P.Sereda,F.A.Gerritsen,A.Vilanova.Mirrored LH Histograms for the Visualization of Material Boundaries[A].In Vision,modeling,and Visualization 2006:proceedings[C].2006,237-244.
[35]P.W.Verbeek and L.J.van Vliet.On the location error of curved edges in low-pass filtered 2-D and 3-D images[J].IEEE Transactions on Pattern Analysis and Machine Intelligence,1994,16(7):726-733.
[36]H.Bouma,A.Vilanova,L.J.van Vliet,and F.A.Gerritsen.Correction for the dislocation of curved surfaces caused by the PSF in 2D and 3D CT images[J].IEEE Transactions of Pattern Analysis and Machine Intelligence,2005,27(9),1501-1507.
[37]M.T.Vlaardingerbroek and J.A.D.Boer,Magnetic resonance imaging:Theory and practice[M],Springer Verlag,1999.
[38]C.D.Correa and D.Silver.Dataset traversal with motion-controlled transfer functions[A].Proceedings IEEE Visualization[C],2005,359-366.
[39]J.Zhou,M.Hinz,and K.Tonnies.Focal region-guided feature-based volume rendering[A]. Proceedings 1st International Symposium on 3D Data Processing Visualization and Transmission[C], 2002, 87-90.
[40] I. Viola, A. Kanitsar, and E. Groller. Importance-driven volume rendering[A]. Proceedings IEEE Visualization[C], 2004, 139-145.
[41] Cabral B, Cam N, et al. Accelerated volume rendering and tomographic reconstruction using texture mapping hardware[A]. In: Proceedings of IEEE Symposium on Volume Visualization[C], 1994,91-98.
[42] Rezk-Salama C, Engel K, et al. Interactive Volume Rendering on Standard PC Graphics Hardware Using Multi-Textures and Multi-Stage Rasterization [A]. In: Proceedings of SIGGRAPH/Eurographics Workshop on Graphics Hardware[C], 2000.
[43] Engel K, Kraus M, et al. High-Quality Pre-Integrated Volume Rendering Using Hardware-Accelerated Pixel Shading[A]. In: Proceeding of Graphics Hardware[C] 2001,9-16.
[44] Kniss J, McCormick P, et al, Interactive texture-based volume rendering for large data sets[J]. IEEE Computer Graphics and Applications, 2001,24(4):52-61.
[45] Phong B T. Illumination for computer generated pictures[J]. Communication of the ACM,1975, 1(18), 311-317.
[46] Engel I, Hastreiter P, et al. Combining Local and Remote Visualization Techniques for Interactive Volume Rendering in Medical Applications[A]. In: Proceeding of Visualization 2000[C]. IEEE Computer Society, 2000, 449-452.
[47] 46 Behrens U, Ratering R. Adding Shadows to a Texture Based Volume Renderer[A]. IEEE Symposium on Volume Visualization[C], Research Triangle Park, NC, IEEE Computer Society, 1998,39-46,165.
[48] elderA N., Kim K. Direct Volume Rendering with Shading via Three Dimensional Textures[A]. In:Proceeding of 1996 Symposium on Volume Visualization[C]. IEEE Computer Society, 1996:23-30.
[49] Westermann R. Ertl T. Effeciently Using Graphics Hardware in Volume Rendering Applications[A]. ACM Computer Graphics (SIGGRAPH'98 Proceedings)[C] , 1998,169-179.
[50] 秦绪佳 医学图像三维重建及可视化技术研究[D]大连:大连理工大学,2001.
[51]ACR-NEMA(American College of Radiology-National Electrical Manufacturers).Digital imaging and communications in medicine(DICOM3.0) International Standard[M].National Electrical Manufactures Association Press.2003,5-17.
[52]Lum E.B.,Ma K.L.Lighting Transfer Function Using Gradient Aligned Sampling[A].In Proc.of IEEE Visualization[C],2004,389-296.
[53]David Marr.Theory of Edge Detection[A].In:Proceedings of the Royal Society[C],London,Vol.B207,1980,187-217.
[54]A.Pommert,U.Tiede,etc.Surface shading in tomographic volume visualization[A],In:Proceedings of the First Conferenceon Visualizationin Biomedical Computing[C],Vol.l,IEEE Computer Society Press,1990:12-26.
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