Adaptive shape from focus with an error estimation in light microscopy

Light microscopy enlarges the viewing angle while decreasing the depth of focus. This leads to mainly blurred images if the specimen being observed consists of significant height changes. In computer vision, solving this problem is known as 'shape from focus'. Algorithms exist that perform both the calculation of a sharp image and the recovery of the three dimensional structure of the specimen. In this paper, three classic approaches for detecting sharp image regions are evaluated. Three new so called focus measures are introduced and are compared to the classic approaches. A new adaptive reconstruction scheme for calculating range images as well as sharp images is presented. Experimental results on synthetic and real data demonstrate the performance of the proposed algorithm.