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，通过采用基于生成辐射模型的通用数学框架，从代表有利位置和/或分辨率的任意组合的场景测量中重建密集的3D物体形状。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。首先要探索的两个例子包括使用薄透镜建模从不同视点和/或焦距获得的未聚焦相机图像，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。该框架将具有足够的通用性，可以应用于红外、声学和SAR等最初研究之外的几种相关传感器模式。此外，拥有统一的模型可以自由地生成灵活的数据捕获和融合方案，在不同的视点和传感器设置特性下捕获不止一组，而是多组测量数据。并且利用收集到的全部数据推断出反射率和几何形状的估计值，相对于在不可能“隔离单个线索”的情况下可能获得的估计值而言，这些估计值的质量更高。例如，对于相机来说，在捕捉不同焦距的图像时，可能无法固定视点（隔离焦点），或者由于镜头的光圈有限（隔离视点），可能无法捕捉到完美清晰的图像。消除这一限制可以使内窥镜检查、管道和裂缝检查、牙印以及环境监测等应用成为可能。

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.