Journal of Applied Crystallography

Volume 46, Part 3 (June 2013)

research papers

J. Appl. Cryst. (2013). 46, 663-671    [ doi:10.1107/S0021889813006511 ]

Objective algorithm to separate signal from noise in a Poisson-distributed pixel data set

T. Straasø, D. Müter, H. O. Sørensen and J. Als-Nielsen

Abstract: A statistical method to determine the background level and separate signal from background in a Poisson-distributed background data set is described. The algorithm eliminates the pixel with the highest intensity value in an iterative manner until the sample variance equals the sample mean within the estimated uncertainties. The eliminated pixels then contain signal superimposed on the background, so the integrated signal can be obtained by summation or by a simple extension by profile fitting depending on the user's preferences. Two additional steps remove `outliers' and correct for the underestimated extension of the peak area, respectively. The algorithm can be easily modified to specific needs, and an application on crystal truncation rods is presented, dealing with a sloping background.

Keywords: background estimation; statistical analysis; image filtering; X-ray diffraction; X-ray detection; neutron diffraction; neutron detection; spot integration.

pdfdisplay filedownload file

Portable Document Format (PDF) file (214.0 kbytes)
[ doi:10.1107/S0021889813006511/rg5027sup1.pdf ]
Brief description of the program SBalgorithm

zipopen filedownload file

Zip compressed file (5.5 kbytes)
[ doi:10.1107/S0021889813006511/ ]
SBalgorithm MATLAB code


To open or display or play some files, you may need to set your browser up to use the appropriate software. See the full list of file types for an explanation of the different file types and their related mime types and, where available links to sites from where the appropriate software may be obtained.

The download button will force most browsers to prompt for a file name to store the data on your hard disk.

Where possible, images are represented by thumbnails.

 bibliographic record in  format

  Find reference:   Volume   Page   
  Search:     From   to      Advanced search

Copyright © International Union of Crystallography
IUCr Webmaster