34-Issue 2

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https://diglib.eg.org/handle/10.2312/12150

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Browsing 34-Issue 2 by Subject "Categories and Subject Descriptors (according to ACMCCS)"

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    Adaptable Anatomical Models for Realistic Bone Motion Reconstruction
    (The Eurographics Association and John Wiley & Sons Ltd., 2015) Zhu, Lifeng; Hu, Xiaoyan; Kavan, Ladislav; Olga Sorkine-Hornung and Michael Wimmer
    We present a system to reconstruct subject-specific anatomy models while relying only on exterior measurements represented by point clouds. Our model combines geometry, kinematics, and skin deformations (skinning). This joint model can be adapted to different individuals without breaking its functionality, i.e., the bones and the skin remain well-articulated after the adaptation.We propose an optimization algorithm which learns the subject-specific (anthropometric) parameters from input point clouds captured using commodity depth cameras. The resulting personalized models can be used to reconstruct motion of human subjects. We validate our approach for upper and lower limbs, using both synthetic data and recordings of three different human subjects. Our reconstructed bone motion is comparable to results obtained by optical motion capture (Vicon) combined with anatomically-based inverse kinematics (OpenSIM). We demonstrate that our adapted models better preserve the joint structure than previous methods such as OpenSIM or Anatomy Transfer.
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    A Biophysically-Based Model of the Optical Properties of Skin Aging
    (The Eurographics Association and John Wiley & Sons Ltd., 2015) Iglesias-Guitian, Jose A.; Aliaga, Carlos; Jarabo, Adrian; Gutierrez, Diego; Olga Sorkine-Hornung and Michael Wimmer
    This paper presents a time-varying, multi-layered biophysically-based model of the optical properties of human skin, suitable for simulating appearance changes due to aging. We have identified the key aspects that cause such changes, both in terms of the structure of skin and its chromophore concentrations, and rely on the extensive medical and optical tissue literature for accurate data. Our model can be expressed in terms of biophysical parameters, optical parameters commonly used in graphics and rendering (such as spectral absorption and scattering coefficients), or more intuitively with higher-level parameters such as age, gender, skin care or skin type. It can be used with any rendering algorithm that uses diffusion profiles, and it allows to automatically simulate different types of skin at different stages of aging, avoiding the need for artistic input or costly capture processes. While the presented skin model is inspired on tissue optics studies, we also provided a simplified version valid for non-diagnostic applications.