纹理映射、合成与替换算法研究
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摘要
纹理指包含一定重复模式又呈现一定随机性的事件,它可以描述自然界中非常广阔的自然现象,例如:声音、图像、视频、运动及几何曲面等等。图形学中的纹理主要指位图图像。采用纹理可以有效表现景物表面的细节特征,增强绘制的真实感。由于纹理技术在影视娱乐、工业设计和虚拟仿真等方面的广泛应用,关于纹理的研究一直是计算机图形学、计算机视觉以及图像处理领域的研究热点。
     本文围绕当前纹理研究中的若干热点问题:约束纹理映射、三维纹理合成、图像和视频的纹理替换及纹理技术在非真实感绘制中的应用等方面展开研究:
     (1)约束纹理映射。纹理映射一般指将二维纹理映射到三维景物表面的过程。可以有效地表现景物表面的纹理细节,提高景物绘制的真实感。本文提出一种基于调和映射的约束纹理映射方法,利用调和映射建立纹理平面和参数化后网格模型的对应关系,给出约束纹理映射问题的一个解析解。由于调和映射具有保持映射能量最小的性质,该方法可以最小化约束纹理映射可能导致的扭曲形变。同时我们还提出一种对映射效果实时优化的算法,有效减少了约束纹理映射的后期交互。
     纹理映射的有效性是约束纹理映射的一个关键问题。本文提出一种基于分块映射的方法,把纹理图像和网格模型按照特征点进行有效剖分并建立对应关系,实现对应的映射,保持了纹理映射这个特殊参数化问题的有效性。由于该方法不需要对网格模型预先参数化,从而提高了纹理映射的效率。同样的思想应用于网格模型的形状过渡也取得了良好的效果。
     (2)三维纹理合成。纹理合成指由一张给定小样本纹理生成大区域纹理的过程。本文提出一种在复杂网格模型表面生成纹理的算法。该算首先建立网格模型的基网格表示,在基网格上合成纹理,然后把合成效果映射回原始网格;在网格模型上建立的基网格可以应用于不同纹理的合成。本文还提出一种对三角形网格的附加纹理图像压缩存储的方法,节约了纹理内存。通过对纹理图像上任意点的邻域预处理编码的方法,进一步提高了合成效率。
     (3)图像和视频的纹理替换。纹理替换指在图像/视频的目标区域采用新的纹理替换原有纹理,在未知原始几何和光源信息的情况下,使替换后目标区域保持原纹理依附在表面上产生的自然变形和光照效果。纹理替换在虚拟展示、影视娱乐等方面有巨大的应用前景。本文通过求解Possion方程保持替换后纹理的依附变形,通过把RGB颜色空间转换到YCbCr颜色空间以及传递Y颜色分量,保持了原纹理的光照效果。
Texture means the thing with repetitive patterns and stochastic attribute. It can describe a wide variety of natural phenomena, such as sound, image, video, motion, surface geometry and so on. Texture in computer graphics generally refers to bitmap image. By means of texture technique, it can simulate efficiently the geometry details of the rendered scene, and meanwhile enhance the visual richness. For the wide applications in TV and file producing, digital entertainment, industrial design and virtual simulation, etc., the research on texture has been one of the hottest topics in computer graphic, vision and image processing.
    In this thesis, some key problems in texture technique: texture mapping, texture synthesis, texture replacement and its application in Non-photo realistic (NPR) rendering are explored, and some new approaches are proposed:
    (1) Constrained texture mapping. Texture mapping is the process of mapping an image onto the 3D model, it can enrich effectively the reality of the rendered scene. This thesis develops a novel constrained texture mapping method based harmonic maps. It constructs the one-to-one correspondence between each point on the embedded meshes and the one on the texture plane, and gives an analytical solution to this problem. The energy minimization characteristic of the harmonic map preserves the low distortion that may yield in the process of texture mapping. Additionally, a real-time optimization algorithm is introduced for reducing the interaction of constrained texture mapping.
    The validity of constrained texture mapping is an important issue, this paper introduces a "divide-and-conquer" method that can ensure its validity. The method divides the texture plane as well as the mesh model into corresponding patches based on the specified feature points, and realizes the mapping for each pair of patches. As the pre-process of parametrization is abandoned, the method is executed with high efficiency. The similar idea can be extended to mesh metamorphosis.
    (2) 3D texture synthesis. Given a texture sample, texture synthesis generates a big size texture that has the similar appearance with the sample. This thesis presents a fast 3D texture synthesis method based on base domain mapping. It first synthesizes texture on the based domain of the input model, which is built adaptively, then maps the result
引文
[1] 彭群生,鲍虎军,金小刚.In计算机真实感图形学的算法基础.北京:科学出版社,1999.
    [2] E. Praun and H. Hoppe. Spherical parameterization and remeshing. In Proc. of SIGGRAPH'2003 (Also ACM Trans. Graphics), volume 22, pages 340-349, San Diego, USA, 2003.
    [3] M. Eck, T. DeRose, T. Duchamp, H. Hoppe, M. Lounsbery, and W. Stuetzle. Mutiresolution analysis of arbitrary meshes. In Proc. of SIGGRAPH'95, pages 173-182, Los Angeles, CA, USA, 1995.
    [4] P. V. Sander, J. Snyder, S. Gortler, and H. Hoppe. Texture mapping progressive meshes. In Proc. of SIGGRAPH'2001, pages 409-416, Los Angeles, CA, USA, 2001.
    [5] M. S. Floater. Mean value coordinates. Computer Aided Geometric Design, 20(1): 19-27, 2001.
    [6] B. Levy, S. Petiejean, N. Ray, and J. Maillot. Least squares conformal maps for automatic texture atlas generation. In Proc. of SIGGRAPH'2002, volume 21, pages 362-371, 2001.
    [7] M. S. Floater. Parametrization and smooth approximation of surface triangulations. Computer Aided Geometric Design, 14(3): 231-250, 1997.
    [8] K. Hormann and G. Greiner. Mips-an efficient global parametrization method. In Curve and Surface Design Conference Proceedings, pages 153-162, Saint, Malo, 1999.
    [9] J. McCarteny, B. K. Hinds, and B. L. Seow. The flattening of triangulated surfaces incorporating darts and gussets. Computer Aided Design, 31(4): 249-260, 1999.
    [10] D. L. Marcum and J. A. Gaiter. Unstructured surface grid generation using global mapping and physical space approximation. In 8th International Meshing Roundtable, pages 397-406, South Lake Tahoe, CA, USA, 1999.
    [11] K. Matsushita and T. Kaneko. Efficient and handy texture mapping on 3d surfaces. Computer Graphics Forum (Also In Proc. Eurographics'1999), 18(3): 349-358, 1999.[12] S. Haker, S. Angenent, A. Tannenbaum, R. Kikinis, G. Sapiro, and M. Halle. Conformal surface parametrization for texture mapping. IEEE Transactions on Visualization and Computer Graphics (ITVCG), 6(2): 181-189, 2000.
    [13] A. Sheffer and E. D. Sturler. Parametrization of faceted surfaces for meshing using angle-based flattening. Engineering with Computers, 17(3): 326-337, 2001.
    [14] A. Sheffer and E. D. Sturler. Smoothing an overlay grid to minimize linear distortion in texture mapping. Acm Trans. Graphics, 21(4): 874-890, 2002.
    [15] P. V. Sander, S. Gortler, J. Snyder, and H. Hoppe. Signal specialized parametrization. In Proc. of Eurographics Workshop on Rendering'2002, 2002.
    [16] M. Desbrun, M. Meyer, and P. Alliez. Intrinsic parametrizations of surfaces meshes. Computer Graphics Forum, 21(3): 210-218, 2002.
    [17] B Levy. Constrained texture mapping for polygonal meshes. In Proc. of SIGGRAPH'2001, pages 417-424, Los Angeles, CA, USA, 2001.
    [18] V. Kraevoy, A. Sheffer, and C. Gotsman. Matchmaker: Constructing constrained texture maps. ACM Transactions on Graphics (Also Siggraph 2003), 22(3): 326-333, 2003.
    [19] Y. W. Guo, J. Wang, H. Q. Sun, and Q. SH. Peng. A novel constrained texture mapping method based on harmonic map. Computers & Graphics, 29(6): 460-468, 2005.
    [20] Y. W. Guo, J. Wang, X. F. Cui, and Q. SH. Peng. A new constrained texture mapping method. In International Conference on Entertainment Computing'2005 (Springer LNCS 3711), Sanda, Japan, Sept. 18-22.
    [21] E. Zuckerberger, A. Tal, and S. Shlafman. Polyhedral surface decomposition with applications. Computers & Graphics, 26(5): 733-743, 2002.
    [22] L. Ecksteinl, V. Surazhsky, and C. Gotsman. Texture mapping with hard constraints. Computer Graphics Forum, 20(3): 95-104, 2001.
    [23] B. Levy and J. L. Mallet. Non-distortion texture mapping for sheared triangulated meshes. In Proc. of SIGGRAPH'98, pages 343-352, Orlando, FL, USA, 1998.[24] Y. Tang, H. J. Wang, J. Bao, and Q. SH. Peng. Rbf-based constrained texture mapping. Computers & Graphics, 27(3): 415-422, 2003.
    [25] P. Duren. Harmonic Mappings in the Plane. PhD thesis, Cambridge University Press, 2004.
    [26] D. Zhang and M. Hebert. Harmonic maps and their applications in surface matching. In IEEE Proceedings of Computer Vision and Pattern Recognition 1999, (CVPR'99), pages 524-530, Colorado, USA, 1999.
    [27] Y. P. Cheng. In Matrix theory, Xian, China, 2001. Northwestern Polytechnical University Press.
    [28] Y. W. Guo, Y. J. Pan, Xo E Cui, and Q. SH. Peng. Harmonic maps based constrained texture mapping method. Computer Aided Design and Computer Graphics (In Chinese), 17(7): 1457-1462, 2005.
    [29] T. Kanai and H. Suzuki. Approximate shortest path on a polyhedral surface and its applications. Computer-Aided Design, 33: 801-811, 2001.
    [30] L. Y. Zhang and X. Wu. Approximate shortest path on triangular mesh surface. Journal of Computer Aided Design & Computer Graphics, 15(5): 592-597, 2003.
    [31] V. Kraevoy and A. Sheffer. Cross-parameterization and compatible remeshing of 3d models. A CM Transactions on Graphics (Also Siggraph 2004), 23(3): 861-869, 2004.
    [32] M. Alexa. Merging polyhedral shapes with scattered features. The Visual Computer, 16(1): 26-37, 2000.
    [33] A. Shapiro and A. Tal. Polyhedron realization for shape transformation. The Visual Computer, 14(8): 429-444, 1998.
    [34] The free dictionary by farlex, http://www.thefreedictionary.com/.
    [35] Edwin E. Catmull. A Subdivision Algorithm for Computer Display of Curved Surfaces. PhD thesis, Dept. of CS, U. of Utah, December 1974.
    [36] P. S. Heckbert. Survey of texture mapping. IEEE Computer Graphics and Applications, 6(11): 56-67, 1986.[37] C. Gotsman, X. Gu, and A. Sheffer. Fundamentals of spherical parameterization for 3d meshes. In Proc. of SIGGRAPH'2003 (Also ACM Trans. Graphics), volume 22, pages 358-363, San Diego, USA, 2003.
    [38] J. E BLINN. Simulation of wrinkled surfaces. Computer Graphics (Siggraph 78), 12 (3): 286-292, 1978.
    [39] G. Y. Gardner. Visual simulation of clouds. Computer Graphics (Siggraph 85), 19(3): 297-303, 1985.
    [40] F. L. Wu, CH. H. Mei, and J. Y. Shi. Method of direct texture synthesis on arbitrary surfaces. Journal of Computer Science and Technology, 19(5): 643-649, 2004.
    [41] K. Zhou, X. Wang, Y. Y. Tong, M. Desbrun, B. N. Guo, and H. Y. Shum. Texture-montage: Seamless texturing of arbitrary surfaces from multiple images. In Proc. of Siggraph'2005, volume 21, pages 1148-1155, Los Angeles, USA, August 2005.
    [42] Cyberware inc., http://www.cyberware.com.
    [43] A. Witkin and M. Kass. Reaction-diffusion textures. Computer Graphics (Siggraph 1991), 25: 299-308, 1991.
    [44] S. P. Worley. A cellular texture basis ftmction. In Siggraph 1996, page 291-294, 1996.
    [45] A. Efros and T. Leung. Texture synthesis by non-parametric sampling. In Interna-tional Conference on Computer Vision'1999, volume 2, pages 1033-1038, Sept. 1999.
    [46] D. J. Heeger and J. R. Bergen. Pyramid-based texture analysis/synthesis. In Proc. of SIGGRAPH 1995, page 229-238, 1995.
    [47] E. Simoncelli and J. Portilla. Texture characterization via joint statistics of wavelet coefficient magnitudes. In Fifth International Conference on Image Processing (ICIP 1998), volume 1, pages 62-66, 1998.
    [48] J. Portilla and E. Simoncelli. A parametric texture model based on joint statistics of complex wavelet coefficients. International Journal of Computer Vision, 40(1): 49-70, 2000.[49] L. Y. Wei and M. Levoy. Fast texture synthesis using tree-structured vector quan-tization. In Proc. of SIGGRAPH 2000, pages 479-488, 2000.
    [50] L. Y. Wei and M. Levoy. Texture synthesis over arbitrary manifold surfaces. In Proc. of SIGGRAPH 2001, pages 355-360, 2001.
    [51] A. A. Efros and W. T. Freeman. Image quilting for texture synthesis and transfer. In Proc. of SIGGRAPH 2001, pages 341-346, Los Angeles, USA, August 2001.
    [52] L. Liang, C. Liu, Y. Q. Xu, B. N. Guo, and H. Y. Shum. Real-time texture synthesis by patch based sampling. ACM Transactions on Graphics, 20(3): 127-150, 2001.
    [53] V. Kwatra, A. Schodl, I. Essa, G. Turg, and A. Bobick. Graphcut texutures: image and video synthesis using graph cuts. In Proc. of SIGGRAPH'2003, volume 22, pages 277-286, San Diego, USA, 2003.
    [54] M. F. Cohen, J. Shade, S. Hiller, and O. Deussen. Wang tiles for image and texture generation. In Proc. of SIGGRAPH'2003, volume 22, pages 287-294, San Diego, USA, 2003.
    [55] N. Andrew and M. Alexa. Hybrid texture synthesis. In Proc. of Eurographics Sym-posium on Rendering'2003, pages 97-105, 2003.
    [56] Q. Wu and Y. Y. Zh. Feature matching and deformation for texture synthesis. In Proc. of SIGGRAPH 2004, pages 364-367, Los Angeles, USA, August 2004.
    [57] G. Turk. Texture synthesis on surfaces. In Proc. of SIGGRAPH'2001, pages 347-354, Los Angeles, CA, USA, 2001.
    [58] S. Magda and D. Kriegman. Fast texture synthesis on arbitrary meshes. In Proc. of Eurographics Symposium on Rendering'2003, pages 82-89, 2003.
    [59] C. Soler, M. P. Cani, and A. Angelidis. Hierarchical pattern mapping. In Proc. of Siggraph'2003, volume 21, pages 673-680, San Diego, USA, 2003.
    [60] J. D. Zhang, K. Zhou, L. Velho, B. N. Guo, and H. Y. Shum. Synthesis of progressively-variant textures on arbitrary surfaces. In Proc. of Siggraph'2003, vol-ume 22, pages 295-302, San Diego, USA, 2003.[61] S. Lefebvre and H. Hoppe. Parallel controllable texture synthesis. In Proc. of Sig-graph'2005, volume 21, pages 777-786, Los Angeles, USA, August 2005.
    [62] W. Matusik, M. Zwicker, and E Durand. Texture design using a simplicial com-plex of morphable textures. In Proc. of Siggraph'2005, volume 21, pages 787-794, Los Angeles, USA, August 2005.
    [63] V. Kwatra, I. Essa, A. F. Bobick, and N. Kwatra. Texture optimization for example-based synthesis. In Proc. of Siggraph'2005, volume 21, pages 795-802, Los Angeles, USA, August 2005.
    [64] L. Y. Wei. Texture synthesis byfixed neighborhood searching. PhD thesis, Standord University, 2001.
    [65] A. Schodl, R. Szeliski, D. H. Salesin, and I. Essa. Video textures. In Proc. of Sig-graph'2000, pages 489-498, New Orleans, USA, July 2000.
    [66] Y. Dobashi, T. Yamamoto, and T. Nishita. Real-time rendering of aerodynamic sound using sound textures based on computational fluid dynamics. In Proc. of SIGGRAPH'2003 (Also ACM Trans. Graphics), volume 22, pages 732-740, San Diego, USA, 2003.
    [67] Y. Li, T. Wang, and H. Y. Shum. Motion texture: a two-level statistical model for character motion synthesis. In Proc. of Siggraph'2002, volume 21, pages 465-472, 2002.
    [68] K. S. Bhat, S. M. Seitz, J. K. Hodgins, and P. K. Khosla. Flow-based video synthesis and editing. In Proc. of Siggraph'2004, pages 360-360, Los Angeles, USA, August 2004.
    [69] F. Tang, Y. T. Ying, J. Wang, and Q. SH. Peng. A novel texture synthesis based algorithm for object removal in photographs. In The 9th Asian Conference of Com-puter Science(Springer Lecture Notes on Computer Science), pages 248-258, Thailand, August.
    [70] J. Sun, L. Yuan, J. Y. Jia, and H. Y. Shum. Image completion with structure prop-agation. In Proc. of Siggraph'2005, volume 21, pages 861-868, Los Angeles, USA, August 2005.[71] M. Lounsbery. Multiresolution Analysis for Surfaces of Arbitrary Topological Type. PhD thesis, University of Washington, 1994.
    [72] D. Dobkin and D. Kirkpatrick. A linear algorithm for determining the separation of convex polyhedra. Journal of Algorithms, 6: 381-392, 185.
    [73] A. W. E Lee, W. Sweldens, P. Schr6der, L. Cowsar, and D. Dobkin. Maps: Mul-tiresolution adaptive parameterization of surfaces. In Proc. of Siggraph'98), pages 95-104. ACM Siggraph, 1998.
    [74] M Ashikhmin. Synthesizing natural textures. In ACM Symposium on Interactive 3D Graphics, page 217-226, March 2003.
    [75] Y. T. Jia, SH. M. Hu, and R. R. Martin. Video completion using tracking and frag-ment merging. The Visual Computer (Also Pacific Graphics 2005), 21: 601-610, 2005.
    [76] X. Tong. Synthesis of bidirectional texture functions on arbitrary surfaces. In Proc. of Siggraph'2002, pages 665-672, San Antonio, Texas, 2002.
    [77] Y. X. Liu and W. C. Lin. Deformable texture: the irregular-regular-irregular cycle. Technical Report CMU-RI-TR-03-26, Robotics Institute, Carnegie Mellon Univer- sity, Pittsburgh, PA, 2003.
    [78] Y. X. Liu, W. C. Lin, and J. Hays. Near regular texture analysis and manipulation. ACM Transactions on Graphics, 23(3): 368-376, 2004.
    [79] H. Fang and J. Hart. Textureshop: texture synthesis as a photograph editing tool. ACM Transactions on Graphics, 23(3): 354-359, 2004.
    [80] S. Zelinka, H. Fang, M. Garland, and J. C. Hart. Interactive material replacement in photographs. In Graphics Interface 2005, pages 227-232, Victoria, USA, May 9-11 2005.
    [81] B. K. Horn. Height and gradient from shading. International Journal of Computer Vision, 5(1): 37-75, 1990.
    [82] B. M. OH, M. Chen, J. Dorsey, and E Durand. Image-based modeling and photo editing. In Proc. of SIGGRAPH 2001, pages 433-442, Los Angeles, California, USA, August 2001. ISBN 1-58113-374-X.[83] Y. Tsin, Y. Liu, and V. Ramesh. Texture replacement in real images. In IEEE Con-ference on Computer Vision and Pattern Recognition 2001, pages 539-544, Kauai Mar-riott, Hawah', USA, July 2001.
    [84] A. Agarwala, A. Hertzmann, D. H. Salesin, and S. M. Seitzl. Keyframe-based tracking for rotoscoping and animation. ACM Transactions on Graphics, 23(3): 584-591, 2004. ISSN 0730-0301.
    [85] D. B. Bradshaw. Motion estimation and compensation of video sequences using affine transforms. PhD thesis, University of Cambridge, 1999.
    [86] J. Wang, Y. Q. Xu, H. Y. Shum, and M. E Cohen. Video tooning. ACM Transactions on Gaphics, 23(3): 574-583, 2004. ISSN 0730-0301.
    [87] T. Welsh, M. Ashikhmin, and K. Mueller. Transferring color to greyscale images. ACM Transactions on Gaphics, 21(3): 277-280, 2002.
    [88] S. S. Beauchemin and J. L. Barron. The computation of optical flow. ACM Com-puting Surveys, 27(3): 433-467, 1995.
    [89] J. B. Shi and C. Tomasi. Good features to track. In IEEE Conference on Computer Vision and Pattern Recognition (CVPR'94), pages 593-600, Seattle, USA, June 1994.
    [90] H. L. Jin, P. Favaro, and S. Soatto. Real-time feature tracking and outlier rejec-tion with changes in illumination. In The Eighth IEEE International Conference on Computer Vision, pages 684--689, Vancouver, Canada, July 2001.
    [91] S. Baker, I. Matthews, J. Xiao, R. Gross, T. Kanade, and T. Ishikawa. Real-time non-rigid driver head tracking for driver mental state estimation. In 11th World Congress on Intelligent Transportation Systems, 2004.
    [92] Y. Altunbasak and A. M. Tekalp. Closed-form connectivity-preserving solutions for motion compensation using 2-D meshes. IEEE Transactions on Image Processing, 6(9): 1255-1269, 1997.
    [93] Y. Y. Chuang, A. Agarwala, B. Curless, D. H. Salesin, and R. Szeliski. Video mat-ting of complex scenes. ACM Transactions on Gaphics, 21(3):243-248, 2002. ISSN 0730-0301.[94] Y. Boykov and M. P. Jolly. Interactive graph cuts for optimal boundary and region segmentation of objects in n-d images. In The Eighth IEEE International Conference on Computer Vision, pages 105-112, Vancouver, Canada, July 2001.
    [95] Y. Li, J. Sun, C. K. Tang, and H. Y. Shum. Lazy snapping. ACM Transactions on Gaphics, 23(3): 303-308, 2004. ISSN 0730-0301.
    [96] Y. Boykov and V. Kolmogorov. An experimental comparison of min-cut/max-flow algorithms for energy minimization in vision. IEEE Transactions on Pattern Analysis and Machine Intelligence, 26(9): 1124-1137, 2004.
    [97] Y. W. Guo, J. Wang, X. Zeng, H. Q. Sun, and Q. SH. Peng. Image and video re-texturing. In Proc. Computer Animation and Social Agents (Also Journal of Computer Animation and Virtual Worlds), volume 16, pages 451-461, Hong Kong, Oct. 19-21 2005.
    [98] A. Hertzmann, N. Oliver, and S. M. Seitz. Curve analogies. In Proc. 13th Euro-graphics Workshop on Rendering, 2002.
    [99] A. Hertzmann. Painterly rendering with curved brush strokes of multiple sizes.In Proc. Siggrpaph'98, pages 453-460, 1998.
    [100] J. Hamel and T. Strothotte. Capturing and re-using rendition styles for non-photorealsitic rendering. Computer Graphics Forum (Eurographics'99), 18(3):173-182, 1999.
    [101] A. Hertzmann, C. E. Jacobs, N. Oliver, and D. H. Curless, B. Salesin. Image analo-gies. In Proc. Siggrpaph'2001, pages 327-340, 2001.
    [102] P. M. Jodoin, E. Epstein, M. Granger-Piche, and V. Ostromoukhov. Hatching by example: A statistical approach. In Proc. Int' l Symp. Non-Photorealistic Animation and Rendering (NPAR 2002), Annecy, France, June 3-5 2002.
    [103] R. D. Kalnins. Wysiwyg npr: Drawing strokes directly on 3d models. ACM Trans. Graphics (Siggraph'2002), 21(3): 755-762, 2002.
    [104] W. T. Freeman, J. B. Tenenbaum, and E. C. Pasztor. An example-based approach to style translation for line drawings. ACM Trans. Graphics, 22(1): 33-46, 2003.[105] B. Wang, W. P. Wang, H. P. Yang, and J. G. Sun. Efficient example-based painting and synthesis of 2d directional texture. IEEE Trans. Visualization and Computer Graphics (TVCG), 10(3): 266-277, 2004.
    [106] M. A. Ruzon and C. Tomasi. Color edge detection with the compass operator. In Proc. of IEEE Conf. CVPR03, pages 160-166, June 1999.
    [107] B. A. Maxwell and S. J. Brubaker. Texture edge detection using compass operator. In Proc. of BMVC 2003, 2003.
    [108] M. Kass, A. Witkin, and D. Terzolpoulos. Snakes: Active contour models. Interna-tional Journal of Computer Vision (IJCV), 2: 321-331,1988.
    [109] D. Comaniciu and P. Meer. Mean shift: A robust approach toward feature space analysis. IEEE Trans. Pattern Analysis and Machine Intelligence (IPAMI), 24(5):603- 619, 2002.
    [110] T. Sederberg and S. Parry. Free-form deformation of solid geometric models. Com-puter Graphics (Siggraph'86), 20(4):151-160, 1986.
    [111] J. C. Carr, R. K. Beatson, J. B. Cherrie, T. J. Mitchell, W. R. Fright, B. C. McCallum, and T. R. Evans. Reconstruction and representation of 3d objects with radial basis functions. In Proc. Siggrpaph'2001, pages 67-76, 2001.

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