Extension of the shape from focus method for reconstruction of high-resolution images

Shape from focus (SFF) estimates the depth profile of a 3D object using a sequence of observations. Due to the finite depth of field of real aperture cameras and the 3D nature of the object, none of the observations is completely in focus. However, in many applications, it is important to examine finer image details of the underlying object in conjunction with the depth map. We propose an extension to the traditional SFF method to optimally estimate a high-resolution image of the 3D object, given the low-resolution observations and the depth map derived from traditional SFF. Using the observation stack, we show that it is possible to achieve significant improvement in resolution. We also analyze the special case of region of interest superresolution and show analytically that an optional interframe separation exists for which the quality of the estimated high-resolution image is the best.