Hawk: the image reconstruction package for coherent X‐ray diffractive imaging

The past few years have seen a tremendous growth in the field of coherent X-ray diffractive imaging, in large part due to X-ray free-electron lasers which provide a peak brilliance billions of times higher than that of synchrotrons. However, this rapid development in terms of hardware has not been matched on the software side. The release of Hawk is intended to close this gap. To the authors' knowledge Hawk is the first publicly available and fully open source software program for reconstructing images from continuous diffraction patterns. The software handles all steps leading from a raw diffraction pattern to a reconstructed two-dimensional image including geometry determination, background correction, masking and phasing. It also includes preliminary three-dimensional support and support for graphics processing units using the Compute Unified Device Architecture, which speeds up processing by orders of magnitude compared to a single central processing unit. Hawk implements numerous algorithms and is easily extended. This, in combination with its open-source licence, provides a platform for other groups to test, develop and distribute their own algorithms. Hawk is available under the GNU General Public License from http://xray.bmc.uu.se/hawk.

[1]  D. R. Luke Relaxed Averaged Alternating Reflections for Diffraction Imaging , 2004, math/0405208.

[2]  J R Fienup,et al.  Reconstruction of an object from the modulus of its Fourier transform. , 1978, Optics letters.

[3]  Veit Elser Phase retrieval by iterated projections. , 2003, Journal of the Optical Society of America. A, Optics, image science, and vision.

[4]  David M. Beazley,et al.  Automated scientific software scripting with SWIG , 2003, Future Gener. Comput. Syst..

[5]  J R Fienup,et al.  Phase retrieval algorithms: a comparison. , 1982, Applied optics.

[6]  M. Fink,et al.  Imaging Processes and Coherence in Physics , 1980 .

[7]  S. Marchesini,et al.  High-resolution ab initio three-dimensional x-ray diffraction microscopy. , 2005, Journal of the Optical Society of America. A, Optics, image science, and vision.

[8]  J. Kirz,et al.  Biological imaging by soft x-ray diffraction microscopy , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[9]  D. Sayre Some implications of a theorem due to Shannon , 1952 .

[10]  Heinz H. Bauschke,et al.  Hybrid projection-reflection method for phase retrieval. , 2003, Journal of the Optical Society of America. A, Optics, image science, and vision.

[11]  Richard A. London,et al.  Femtosecond time-delay X-ray holography , 2007, Nature.

[12]  W. H. Benner,et al.  Femtosecond diffractive imaging with a soft-X-ray free-electron laser , 2006, physics/0610044.

[13]  D. Garzella,et al.  Single-shot diffractive imaging with a table-top femtosecond soft x-ray laser-harmonics source. , 2009, Physical review letters.

[14]  Heinz H. Bauschke,et al.  A strongly convergent reflection method for finding the projection onto the intersection of two closed convex sets in a Hilbert space , 2006, J. Approx. Theory.

[15]  G. Oszlányi,et al.  Ab initio structure solution by charge flipping. II. Use of weak reflections. , 2005, Acta crystallographica. Section A, Foundations of crystallography.

[16]  J. Miao,et al.  Extending the methodology of X-ray crystallography to allow imaging of micrometre-sized non-crystalline specimens , 1999, Nature.

[17]  Steven G. Johnson,et al.  The Design and Implementation of FFTW3 , 2005, Proceedings of the IEEE.

[18]  S. Marchesini,et al.  X-ray image reconstruction from a diffraction pattern alone , 2003, physics/0306174.

[19]  R. Gerchberg A practical algorithm for the determination of phase from image and diffraction plane pictures , 1972 .

[20]  S. Marchesini,et al.  Ultrafast single-shot diffraction imaging of nanoscale dynamics , 2008 .

[21]  G. Oszlányi,et al.  Ab initio structure solution by charge flipping. , 2003, Acta crystallographica. Section A, Foundations of crystallography.