摘要 |
According to one embodiment, an apparatus for determining the gradients of the surface normals of an object includes a receiving unit, establishing unit, determining unit, and selecting unit. The receiving unit is configured to receive data of three 2D images of the object, wherein each image is taken under illumination from a different direction. The establishing unit is configured to establish which pixels of the image are in shadow such that there is only data available from two images from these pixels. The determining unit is configured to determine a range of possible solutions for the gradient of the surface normal of a shadowed pixel using the data available for the two images. The selecting unit is configured to select a solution for the gradient using the integrability of the gradient field over an area of the object as a constraint and minimizing a cost function. |