CIF: Small: Geometric, Variational Algorithms for Radiometric-Based Shape Reconstruction

研究人员将开发一类新的变分几何逆算法，通过采用基于生成性辐射测量模型的通用数学框架，从表示有利位置和/或分辨率的任意组合的场景测量中重建对象的密集3D形状。在CAD模型不可用或不可能的情况下，从原始传感器数据重建形状是图形3D渲染和分析的必要步骤。要初步探索的两个例子包括使用薄透镜模型从不同视角和/或焦距拍摄的未聚焦相机图像，以及从具有不同天线位置和/或波长的附近物体反射的雷达信号。该框架将足够通用，以适用于最初研究的几种相关传感器模式，包括红外、声学和合成孔径雷达。此外，具有统一的模型提供了生成灵活的数据捕获和融合方案的自由，其中在不同的视点和传感器设置特征下捕获不是一个而是多个测量集合，并且使用整个收集的数据集合来推断相对于在不可能获得单一线索的情况下可能获得的更高质量的反射率和几何估计。例如，对于相机，在捕获不同焦点的图像时可能无法固定视点(隔离焦点)，或者由于镜头的有限光圈(隔离视点)而无法捕获完全清晰的图像。消除这一限制可以应用于内窥镜检查、管道和缝隙检查、牙齿印模以及环境监测。

The investigator will develop a new class of variational geometric inverse algorithms for reconstructing dense 3D shape of objects from measurements of a scene representing an arbitrary combination of vantage points and/or resolution by employing a common mathematical framework based on generative radiometric models. Reconstruction of shape from raw sensor data is a necessary step for graphical 3D rendering and analysis in scenarios where CAD models are unavailable or impossible. Two examples to be initially explored include unfocussed camera images from different viewpoints and/or focal lengths using thin-lens modelling, and radar signals reflected from nearby objects with different antenna locations and/or wavelengths.The framework will be general enough to apply to several related sensor modalities beyond those initially investigated, ranging from infrared, acoustics, and SAR. Furthermore, having a unified model affords the freedom to generate flexible data capture and fusion schemes where not one, but multiple sets of measurements are captured under different viewpoint and sensor setting characteristics, and use the entire set of collected data to infer an estimate of reflectance and geometry that is of superior quality relative to what may be obtained in scenarios where "isolating a single cue" is not possible. For instance, with cameras, it may be impossible to fix the viewpoint while capturing images of different focus (isolating focus), or to capture perfectly sharp images because of the finite aperture of the lens (isolating viewpoint). Removing this constraint can enable applications to endoscopy, inspection of pipes and crevices, dental impressions, as well as environmental monitoring.