Fig. 2From: Improved tomographic reconstruction of large-scale real-world data by filter optimizationReconstructions of the Shepp–Logan head phantom with the SIRT-FBP method, using different discretizations of the system matrix during filter computation. In a the Joseph kernel is used, in b rays are modeled by a line, and in c rays are modeled by a strip with the same width as a detector pixelBack to article page