The Graz Application for Tomographic Reconstruction (Graptor) is a software tool developed to allow for efficient, high quality tomographic reconstruction from Radon-transform data. It originates from a project concerning Scanning Transmission Electron Tomography of the Institute of Mathematics and Scientific Computing at the University of Graz together with the Institute for Electron Microscopy and Nanoanalysis and the Centre for Electron Microscopy at Graz University of Technology, though it is not limited to such applications. A special feature of this toolbox is the coupling in multi-channel tomography (originally developed for joint HAADF-EDX reconstruction), yielding superior reconstruction quality for data sets with complementing information. The reconstruction algorithm bases on an iterative procedure that minimizes the Tikhonov functional associated with the tomographic reconstruction problem and multi-channel total generalized variation regularization. The code features a powerful OpenCL/GPU implementation, resulting in high reconstruction speed, and a Graphical User Interface allowing for easy use. Highlights: High quality tomography reconstructions. Easy to use graphical user interface. Fast reconstruction due to custom OpenCL/GPU-implementation. Preprocessing options to ensure data fits the framework.

Partially supported by the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 823717 ESTEEM3.