Fig. 4From: Improved tomographic reconstruction of large-scale real-world data by filter optimizationSIRT-FBP reconstructions of the Shepp–Logan head phantom using a, b the BTF approach and c the FTB approach. In a and c the backprojection operation is performed using a grid as large as the field-of-view, while in b a grid that is four times larger than the field-of-view is usedBack to article page