Application of signal separation to diffraction image compression and serial crystallography

We present here a methodology for real-time analysis of diffraction images acquired at a high frame rate (925 Hz) and its application to macromolecular serial crystallography at ESRF. We introduce a new signal-separation algorithm, able to distinguish the amorphous (or powder diffraction) component from the diffraction signal originating from single crystals. It relies on the ability to work efficiently in azimuthal space and is implemented in <i>pyFAI</i>, the fast azimuthal integration library. Two applications are built upon this separation algorithm: a lossy compression algorithm and a peak-picking algorithm. The performances of both are assessed by comparing data quality after reduction with <i>XDS</i> and <i>CrystFEL</i>.