IMAGENCIF: AN INITIATIVE TO STANDARDISE IMAGE FORMATS. A P Hammersley,ESRF, BP 220, 38043 Grenoble Cedex, France

A working group, self-named as "imageNCIF", has been formed to extend the CIF concept to cover the storage of area detector data. It has developed out of discussions which took place at a computing workshop held at the Brookhaven National Laboratory in March 1995 [1]. The principle goals are to provide a header that describes the data and may contain auxiliary information needed by analysis software, and to produce a simple efficient storage format.

E-mail discussions have led to the conclusion that a true CIF (ASCII-text based) format is not appropriate for raw area detector data, simply because of the quantity of data involved (Mbytes for an image and maybe Gbytes for a data-set). A CIF-compatible format is developing, where a binary file would consist of a text header followed by the data. The header section would conform to all normal CIF rules except, perhaps, for the manner in which "lines" of text were separated. The image data would follow in a binary section. Items such as the size of the binary data and the manner in which individual elements were stored would be described in the header section through additional CIF data names. A simple utility program would be provided to extract the CIF-compatible section from the binary file, and output a true CIF.

[1] R Sweet, "A Workshop on Graphical User Interfaces for Synchrotron Protein Crystallography", Synchrotron Radiation News, Vol. 8, No. 5, pp 6-7 (1995).