Accurate reconstruction of 3D geometrical shape from a set of calibrated 2D
multiview images is an active yet challenging task in computer vision. The existing
multiview stereo methods usually perform poorly in recovering deeply concave and thinly
protruding structures, and suffer from several common problems like slow convergence,
sensitivity to initial conditions, and high memory requirements. To address these issues,
we propose a two-phase optimization method for generalized reprojection error minimization
(TwGREM), where a generalized framework of reprojection error is proposed to integrate
stereo and silhouette cues into a unified energy function. For the minimization of the
function, we first introduce a convex relaxation on 3D volumetric grids which can be
efficiently solved using variable splitting and Chambolle projection. Then, the resulting
surface is parameterized as a triangle mesh and refined using surface evolution to obtain
a high-quality 3D reconstruction. Our comparative experiments with several
state-of-the-art methods show that the performance of TwGREM based 3D reconstruction is
among the highest with respect to accuracy and efficiency, especially for data with smooth
texture and sparsely sampled viewpoints.