Discussion List Archives

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Image Headers in cif.

 	Jim Pflugrath has asked what his header would look like if it were
 to be presented as a cif.  I give one possibilty below.  The names are, of
 course, arbitrary at this stage, but they are the names that might
 plausibly be found in a cif dictionary for images.  As with all cif names,
 they tend to suggest the nature of the data item that they define, though 
 this is not a requirement. 
 
 data_sample  # Every data block starts with 'data_'.  The name 'sample' is 
 # 		user assigned 
 #
 # Any text that follows the # sign on a given line is a comment and is not
 # part of the cif itself.  This convention is particularly useful for 
 # documenting samples like this.
 # It does, however, require the use of line feeds to delimit the lines
 #
 _image_size_dimension 	2
 _image_size_first_dim	3076
 _image_size_second_dim	3076
 _image_size_third_dim	?	# This field is not necessary in this case
 #		but is included to show how undefined fields can be handled
 _image_data_type	usi	# 'usi' is a code defined in the dictionary
 #		that stands for 'unsigned short integer'
 _image_data_endian	big
 _image_compression_type siemens_1
 loop_
 _image_compression_table
 	  324
	  455
 	12312
 #	etc. etc.
 # The block ends with end-of-file or the 'data_' name of a new data block.
 
 	I am not sure what all the numbers in the above example mean as I 
 have not yet had direct experience with image data.  It is possible that 
 there may be better ways of presenting this information in cif format, 
 but this example will give the general idea.
 
 			David Brown
 
 
 *****************************************************
 Dr.I.D.Brown
 Brockhouse Institute for Materials Research, 
 McMaster University, Hamilton, Ontario, Canada
 1-(905)-525-9140 ext 24710
 *****************************************************

Reply to: [list | sender only]
International Union of Crystallography

Scientific Union Member of the International Science Council (admitted 1947). Member of CODATA, the ISC Committee on Data. Partner with UNESCO, the United Nations Educational, Scientific and Cultural Organization in the International Year of Crystallography 2014.

International Science Council Scientific Freedom Policy

The IUCr observes the basic policy of non-discrimination and affirms the right and freedom of scientists to associate in international scientific activity without regard to such factors as ethnic origin, religion, citizenship, language, political stance, gender, sex or age, in accordance with the Statutes of the International Council for Science.

Useful links