RC - Real Convolution ||

PURPOSE

Computes convolution product between picture and specified matrix (point spread function (PSF)) in real space. PSF is assumed square/cubic.   Example.

USAGE

.OPERATION: RC

.INPUT FILE: PIC001
[Enter name of image/volume to be convoluted.]

.OUTPUT FILE: PIC002
[Enter name of image/volume where convoluted values are placed.]

.PSF INPUT FILE: PSF001 / * / #
[Enter (1) Name of file where PSF matrix is found,
(2) '*' to indicate that PSF matrix is typed in and not saved,
(3) '#' to indicate that PSF is typed in and is saved.]

If 'PSF INPUT FILE' is an existing PSF file, SPIDER will read in the SPIDER image format PSF file and print out its values:

.PSF IN USE

-0.1 -0.1 -0.2 -0.1 -0.1
-0.1 -0.1 -0.3 -0.1 -0.1
-0.1 -0.1 3.0 -0.1 -0.1
-0.1 -0.1 -0.3 -0.1 -0.1
-0.1 -0.1 -0.2 -0.1 -0.1

[The convolution product between PIC001 and PSF001 is then computed and written into PIC002.]

If 'PSF INPUT FILE' is '*', SPIDER will read in the PSF values:

.PSF WIDTH: 5
[Enter linear size of PSF matrix. Number must be odd. See notes regarding range.

Enter matrix, with <PSF WIDTH> numbers per line]

.ROW(1): -0.1 -0.1 -0.2 -0.1 -0.1


.ROW(1): -0.1 -0.1 -0.3 -0.1 -0.1


.ROW(1): -0.1 -0.1 3.0 -0.1 -0.1


.ROW(1): -0.1 -0.1 -0.3 -0.1 -0.1


.ROW(1): -0.1 -0.1 -0.2 -0.1 -0.1

[SPIDER will then normalize the PSF and print out the PSF IN EFFECT. Then the convolution product between PIC001 and PSF001 is then computed and written into PIC002.]

If 'PSF INPUT FILE' is '#', SPIDER will read in the name of the

PSF output file and the PSF values:

.PSF OUTPUT FILE: PSF002
[Enter name of file where PSF matrix is to be saved.]

.PSF WIDTH: 5
[Enter linear size of PSF matrix. Number must be odd. See notes regarding range.

Enter matrix, with <PSF WIDTH> numbers per line]

.ROW(1): -0.1 -0.1 -0.2 -0.1 -0.1


.ROW(1): -0.1 -0.1 -0.3 -0.1 -0.1


.ROW(1): -0.1 -0.1 3.0 -0.1 -0.1


.ROW(1): -0.1 -0.1 -0.3 -0.1 -0.1


.ROW(1): -0.1 -0.1 -0.2 -0.1 -0.1

[SPIDER will then normalize the PSF and print out the PSF IN EFFECT. Then the convolution product between PIC001 and PSF001 is then computed and written into PIC002.]

NOTES

1. If PSF has "box" form (i.e., all coefficients of matrix have equal value), use box convolution ('BC') instead.

2. Fourier convolution, 'CN', is the method of choice for large PSFs (with PSFs as large as the image!).

3. 'RC' has been rarely used since it was first written. It is possible that bugs have developed over the years.

SUBROUTINES

RCONV, RCNV3_P, RCNV2_P

CALLER

UTIL3