AC NS - Self Correlation - Normalized ||

(10/08/00)

PURPOSE

Computes the self-correlation function of an image/volume by using the Fourier transform relationship.   Example.

SEE ALSO

AC N [Auto Correlation - Normalized ||]
AC S [Self Correlation ||]
AC MS [Auto Correlation - Masked and normalized ||]
CC [Cross Correlation ||]
CC N [Cross Correlation - Normalized ||]
CN [Convolution ||]
CN N [Convolution - Normalized ||]
FT [Fourier Transform ||]

USAGE

.OPERATION: AC NS

.INPUT FILE: PIC001
[Enter the name of the image/volume to be self-correlated.]

.OUTPUT FILE: ACF001
[Enter name of the file which will contain the self-correlation coefficients.]

NOTES

  1. On completion of this operation, the output file will contain the self-correlation function.
    The origin is at (INT(NX/2) + 1, INT(NY/2) + 1, INT(NZ/2) + 1).
    The SCF is not normalized.

  2. The type of input data can be either real or Fourier.

  3. The self-correlation function is defined in "Correlation functions revisited", M. van Heel, M. Schatz, E. Orlova. Ultramicroscopy, 46, (1992) 307-316; as inverse Fourier transform of the square root of the modulus of the Fourier transform of the input image.

SUBROUTINES

FMRS_2, FMRS_2R, FFTMCF, FMRS_1, FMRS_3, FMRS_3R, ACRS_2S, ACRS_3S

CALLER

CORR1

© Copyright Notice /       Enquiries: spider@wadsworth.org