David C. Schneider

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Mesh-based deformable image alignment (MDIA) is an algorithm that warps a template image onto a target by deforming a 2D control mesh in the image plane, using an image-based nonlinear optimization strategy. MDIA has been successfully applied to various nonrigid registration problems, deformable surface tracking and stabilization of scene-to-camera motion(More)
Several recent, high-impact ecological studies feature natural microcosms as tools for testing effects of fragmentation, metacommunity theory or links between biodiversity and ecosystem processes. These studies combine the microcosm advantages of small size, short generation times, contained structure and hierarchical spatial arrangement with advantages of(More)
We propose an algorithm for non-rigidly registering a 3D template mesh with a dense point cloud, using a morphable shape model to control the deformation of the template mesh. A cost function involving nonrigid shape as well as rigid pose is proposed. Registration is performed by minimizing a first-order approximation of the cost function in the Iterative(More)
Two methods for registering laser-scans of human heads and transforming them to a new semantically consistent topology defined by a user-provided template mesh are described. Both algorithms are stated within the Iterative Closest Point framework. The first method is based on finding landmark correspondences by iteratively registering the vicinity of a(More)
Augmenting cloth in real video is a challenging task because cloth performs complex motions and deformations and produces complex shading on the surface. Therefore, for a realistic augmentation of cloth, parameters describing both deformation as well as shading properties are needed. Furthermore, objects occluding the real surface have to be taken into(More)
Detecting habitat selection depends on the spatial scale of analysis, but multi-scale studies have been limited by the use of a few, spatially variable, hierarchical levels. We developed spatially explicit approaches to quantify selection along a continuum of scales using spatial (coarse-graining) and geostatistical (variogram) pattern analyses at multiple(More)
This paper formulates the Shape-from-Texture (SFT) problem of deriving the shape of an imaged surface from the distortion of its texture as a single-plane/multiple-view Structure-from-Motion (SFM) problem under full perspective projection. As in classical SFT formulations we approximate the surface as being piecewise planar. In contrast to many methods, our(More)
The paper addresses the task of fitting a morphable head model to a dense, unstructured and untextured point cloud. The problem is typically approached in a multi-step process, comprising of generic non-rigid registration, conversion to the model's topol-ogy and fitting of the model. Here, a direct approach is proposed where the morphable model is fitted to(More)
The paper presents an approach for reconstructing head-and-shoulder portraits of people from calibrated stereo images with a high level of geometric detail. In contrast to many existing systems, our reconstructions cover the full head, including hair. This is achieved using a global intensity-based optimization approach which is stated as a parametric warp(More)