Abstract
Direct volume rendering is one of the most effective ways to visualize volume data sets, which employs intuitive 2D images to display internal structures in 3D space. However, opaque features always occlude other parts of the volume, and make some features of interest invisible in the final rendered images. Although a class of highly transparent transfer functions are capable of revealing all features at once, it is still laborious and time-consuming to specify appropriate transfer functions to reduce occlusions on less important structures and highlight features of interest, even for experts. Thus, the research on simpler volume visualization techniques which do not rely on complex transfer functions has been a hotspot in many practical applications. In this paper, an occlusion-free feature exploration approach that consists of modifying the traditional volume rendering integral is proposed, which can achieve better visibility of all internal features of interest with simple linear transfer functions. During the ray casting, a modulation parameter is derived to reduce the contributions of previous samples along the viewing ray, whenever the accumulated opacity value is close to overflow. In addition, several relevant functions are introduced to refine the modulation parameter and highlight the features of interest identified according to the attributes such as scalar, gradient module, occurrence and depth. Thereby, the proposed approach is capable of generating informative rendered images and enhancing the visual perception of features of interest without resorting to complex transfer functions.
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References
Bruckner S, Difference Gröller ME (2009) Instant Volume Visualization using Maximum Intensity Accumulation[J]. Computer Graphics Forum 28(3):775–782
Bruckner S, Grimm S, Kanitsar A, et al. (2006) Illustrative Context-Preserving Exploration of Volume Data[J]. IEEE Trans. Vis. Comput. Graph. 12(6):1559–1569
Cheuk Y, Varshney A, Jaja J (2012) Hierarchical Exploration of Volumes Using Multilevel Segmentation of the Intensity-Gradient Histograms[J]. IEEE Trans. Vis. Comput. Graph. 18(12):2355–2363
Correa C, Kwan-Liu M (2008) Size-based Transfer Functions: A New Volume Exploration Technique[J]. IEEE Trans. Vis. Comput. Graph. 14(6):1380–1387
Correa C, Ma K (2011) Visibility Histograms and Visibility-Driven Transfer Functions[J]. IEEE Trans. Vis. Comput. Graph. 17(2):192–204
Diaz J, Vazquez P (2010) Depth-enhanced maximum intensity projection[C]. IEEE Volume Graphics:93–100
Haidacher M, Bruckner S, Groller ME (2011) Volume Analysis using Multimodal Surface Similarity[J]. IEEE Trans. Vis. Comput. Graph. 17(12):1969–1978
Haidacher M, Patel D, Bruckner S, et al. (2010) Volume Visualization based on Statistical Transfer-Function Spaces[C]. IEEE Pacific Visualization Symposium:17–24
Hanqi G, Ningyu M, Xiaoru Y (2011) WYSIWYG (What You See is What You Get) Volume Visualization[J]. IEEE Trans. Vis. Comput. Graph. 17(12):2106–2114
Heidrich W, McCool M, Stevens J (1995) Interactive Maximum Projection Volume Rendering[C]. IEEE Visualization:11–18
Kindlmann G, Whitaker R, Tasdizen T, et al. (2003) Curvature-based Transfer Functions for Direct Volume Rendering: Methods and Applications[C]. IEEE Visualization:513–520
Kniss J, Kindlmann G, Hansen C (2002) Multidimensional Transfer Functions for Interactive Volume Rendering[J]. IEEE Trans. Vis. Comput. Graph. 8(3):270–285
Levoy M (1988) Display of Surfaces from Volume Data[J]. IEEE Comput. Graph. Appl. 8(3):29–37
Liang R, Wu Y, Dong F, Gordon C (2012) Accumulation of Local Maximum Intensity for Feature Enhanced Volume Rendering[J]. Vis. Comput. 28(6-8):625–633
Max N (1995) Optical Models for Direct Volume Rendering[J]. IEEE Trans. Vis. Comput. Graph. 1(2):99–108
Prassni JS, Ropinski T, Mensmann J, et al. (2010) Shape-based Transfer Functions for Volume Visualization[C]. IEEE Pacific Visualization Symposium:9–16
Roettger S, Bauer M, Stamminger M (2005) Spatialized Transfer Functions[C]. Eurographics/IEEE VGTC Symposium on Visualization:271–278
Ropinski T, Prassni JS, Steinicke F, et al (2008) Stroke-based Transfer Function Design[C]. IEEE International Symposium on Volume and Point-Based Graphics:41–48
Ruiz M, Bardera A, Boada I, et al. (2011) Automatic Transfer Functions Based on Informational Divergence[J]. IEEE Trans. Vis. Comput. Graph. 17(12):1932–1941
Schreiner S, Jr. Galloway RL (1993) A Fast Maximum-Intensity Projection Algorithm for Generating Magnetic Resonance Angiograms[J]. IEEE Trans. Med. Imaging 12(1):50–57
Sereda P, Bartroli AV, Serlie IWO, et al. (2006) Visualization of Boundaries in Volumetric Data Sets using LH Histograms[J]. IEEE Trans. Vis. Comput. Graph. 28(3):208–218
Yingcai W, Huamin Q (2007) Interactive Transfer Function Design Based on Editing Direct Volume Rendered Images[J]. IEEE Trans. Vis. Comput. Graph. 13(5):1027–1040
Yunhai W, Wei C, Jian Z, et al. (2011) Efficient Volume Exploration Using the Gaussian Mixture Model[J]. IEEE Trans. Vis. Comput. Graph. 17(11):1560–1573
Zhiguang Z, Yubo T, Hai L, et al. (2011) Shape-enhanced Maximum Intensity Projection[J]. Vis. Comput. 27(6-8):677–686
Acknowledgments
The authors would like to thank the anonymous reviewers for their valuable comments. This work was supported by NFS of China Project (No.61303133, 61100084), Zhejiang Science & Technology Plan of China (No.2014C31057), 863 Program Project (No.2012AA12A404) and the Open Project Program of the State Key Lab of CAD&CG (Grant No. A1417), Zhejiang University. The data sets are courtesy of VoreenPub, The Visible Human Project, General Electric, and Philips Research.
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Zhou, Z., Tao, Y., Lin, H. et al. Occlusion-free feature exploration for volume visualization. Multimed Tools Appl 74, 10243–10258 (2015). https://doi.org/10.1007/s11042-014-2162-4
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DOI: https://doi.org/10.1007/s11042-014-2162-4