OR A - ORientation search - 2D, using self-correlation ||

PURPOSE

Determines rotational and translational orientation between two images using self-correlation functions.

SEE ALSO

OR Q	[ORientation search - 2D, multireference, using self-correlation ||]
AP SH	[Alignment - multi-reference, exhaustive rotation & shift ||*]

USAGE

.OPERATION: OR A [rot],[xsh],[ysh],[mir],[cc]

[The optional output registers contain: [rot] - rotation angle, [xsh],[ysh] - X- and Y- shifts, [mir] is 0 when there is no mirror, and 1 when there is mirror operation necessary, [cc] - not-normalized correlation coefficient.]

.INPUT FILE: UUU001
[Enter name of the file.]

.REFERENCE FILE: GGG002
[Enter the name of the file containing the reference image; dimensions must correspond to those of the first input image.]

.REAL SPACE MASK RADIUS FOR THE INPUT AND REFERENCE IMAGES: 25,15
[The radii applied in real space to the input and reference images, respectively.]

.RADIUS OF ACF, MAXIMUM SHIFT: 20,5
[Enter the maximum radius of the self-correlation function to be used in angle determination and the maximum shift to be considered.]

.CHECK MIRRORED POSITIONS (0=NOCHECK / 1=CHECK) : 1
[Check mirrored image when using 1/2 coverage of projection space.]

NOTES

1. This command employs the same method as 'AP SH'. For details see:
   Joyeux, L. and P.A. Penczek. Efficiency of 2D alignment methods. Ultramicroscopy, 92, 33-46 (2002).
   

2. Implemented by: Paul Penczek

3. WARNING, the sub-pixel location seems to have a systematic shift error of 0.3 pixel when checked versus known image displacements.

SUBROUTINES

ORACFMSK, ORACFMSKM, FRNG, CROSRNG_MS, CROSRNG_DS, RTQ_Q, FMRS_2, CCRS_2, FINDMX_Q, FMRS_2R

CALLER

UTIL3