A Focal Cue for Metric Measurement of 3D Surfaces

This paper finds a method for computing the best-focused location from an image and using it as a dimensional cue for acquisition of a 3D scene surface. In some situations in 3D vision, an object cannot be reconstructed into a 3D model with metric dimensions. Rather, it can only be reconstructed into a 3D structure up to a similarity transformation. To upgrade the 3D model from a similarity transformation to a Euclidean transformation, we propose a method based on the best-focused locations. By analyzing the blur distribution in an image, this method finds the best-focused locations from an image, which provides an additional cue for upgrading the reconstructed 3D structure. Hence, we can obtain not only the object´s shape, but also the dimensions and sizes of surface features