Estimating body shape of dressed humans

The paper presents a method to estimate the detailed 3D body shape of a person even if heavy or loose clothing is worn. The approach is based on a space of human shapes, learned from a large database of registered body scans. Together with this database we use as input a 3D scan or model of the person wearing clothes and apply a fitting method, based on ICP (iterated closest point) registration and Laplacian mesh deformation. The statistical model of human body shapes enforces that the model stays within the space of human shapes. The method therefore allows us to compute the most likely shape and pose of the subject, even if it is heavily occluded or body parts are not visible. Several experiments demonstrate the applicability and accuracy of our approach to recover occluded or missing body parts from 3D laser scans.     

Hologram reconstruction corrected for measurements through layers with different refractive indices in digital in-line holographic microscopy

Digital in-line holographic microscopy (DIHM) using point sources has been shown to be a versatile technique, especially for three-dimensional tracking of particles or microorganisms. However, the spherical source wave is altered when measurements are performed through layers with different refractive indices, such as water cuvettes. The situations where a layer of medium with a refractive index different than that of the predominant surrounding propagation medium (usually air) is situated behind or in front of the plane to be reconstructed are analyzed in detail, and a general approach for reconstruction under such circumstances is developed. The proposed refractive index correction is tested experimentally and compared to conventional reconstruction algorithms. Using 3D traces of swimming algal spores, the influence on the velocity calculation is also shown.     

Growth of copper and vanadium on a thin Al2O3-film on Ni3Al(111)

The growth of different metals on thin Al₂O₃-films on Ni₃Al(111) was investigated using scanning tunneling microscopy (STM). These thin alumna films are well ordered showing two superstructures, which appear in the STM images at different bias voltages. These superstructures, with periodicities of 2.6 and 4.5 nm, respectively, are shown here to govern the nucleation of the deposited metals. Copper clusters grow on these nucleation centers only at room temperature. Higher temperatures lead to an increase of the cluster size and the loss of order. In turn, vanadium forms ordered cluster arrays at room and higher temperature. Due to the stronger metal–oxide interaction compared to copper vanadium forms smaller clusters at low and high coverages, which do not show any ripening after annealing. Based on these observations, Al₂O₃-films on Ni₃Al(111) prove to be an interesting template for the fabrication of periodic cluster arrays.     

A system for articulated tracking incorporating a clothing model

In this paper an approach for motion capture of dressed people is presented. A cloth draping method is incorporated in a silhouette based motion capture system. This leads to a simultaneous estimation of pose, joint angles, cloth draping parameters and wind forces. An error functional is formalized to minimize the involved parameters simultaneously. This allows for reconstruction of the underlying kinematic structure, even though it is covered with fabrics. Finally, a quantitative error analysis is performed. Pose results are compared with results obtained from a commercially available marker based tracking system. The deviations have a magnitude of three degrees which indicates a reasonably stable approach.     

Digital in-line soft x-ray holography with element contrast

Digital in-line soft x-ray holography (DIXH) was used to image immobilized polystyrene and iron oxide particles and to distinguish them based on their different x-ray absorption cross sections in the vicinity of the carbon K-absorption edge. The element-specific information from the resonant DIXH images was correlated with high-resolution scanning electron microscopy (SEM) pictures. We also present DIXH images of a cell nucleus and compare the contrast obtained for nuclear components with the appearance in optical microscopy.     

Tuning the Cell Adhesion on Biofunctionalized Nanoporous Organic Frameworks

The ability to control the structure and surface chemistry of biomaterials on a molecular level is crucial for optimizing their performance. Here, a novel type of nanoporous organic framework that is suited for the fabrication of thin films is described. These surface‐grafted gels (SURGELs) are prepared and functionalized using two orthogonal, metal‐free click chemistries. The SURGELs are shown to be cytocompatible and to efficiently mediate adhesion of osteoblast‐like cells. This process can be further enhanced by surface modification. In addition, the use of light‐triggered reactions in combination with photomasks allows a patterned functionalization of the substrates. The potential to vary and exactly adjust the parameters within the SURGEL polymer network (including porosity and exact network topology on the nanometer scale as well as addressable functional groups) combined with the ability to functionalize their surfaces with any clickable biomolecule of choice in any desired pattern allow the targeted design of novel SURGEL‐based biomaterials for applications in nanomedicine, tissue engineering scaffolds, wound dressing,and medical implants.     

Estimating layout of cluttered indoor scenes using trajectory-based priors

Given a surveillance video of a moving person, we present a novel method of estimating layout of a cluttered indoor scene. We propose an idea that trajectories of a moving person can be used to generate features to segment an indoor scene into different areas of interest. We assume a static uncalibrated camera. Using pixel-level color and perspective cues of the scene, each pixel is assigned to a particular class either a sitting place, the ground floor, or the static background areas like walls and ceiling. The pixel-level cues are locally integrated along global topological order of classes, such as sitting objects and background areas are above ground floor into a conditional random field by an ordering constraint. The proposed method yields very accurate segmentation results on challenging real world scenes. We focus on videos with people walking in the scene and show the effectiveness of our approach through quantitative and qualitative results. The proposed estimation method shows better estimation results as compared to the state of the art scene layout estimation methods. We are able to correctly segment 90.3% of background, 89.4% of sitting areas and 74.7% of the ground floor.