RT C - RoTate - image, around arbitrary center, for small files

PURPOSE

Rotates an image counter-clockwise around a center specified by the user. (Negative angles: clockwise. Note that the notions "clockwise" and "counter-clockwise" refer to the mirrored x-y system used for image display). The background rotated into the image field is the average of the input image.

SEE ALSO

RT	[RoTate - image or volume, use average as background]
RT 3	[RoTate - volume, slow]
RT 3A	[RoTate - volume, arbitrary center, quadratic interpolation]
RT 3D	[RoTate - volume, fast, quadratic interpolation]
RT 90	[RoTate - image or volume, by 90, 180, or 270 degrees]
RT B	[RoTate - image or volume, supply Background]
RT M	[RoTate - image or volume, use minimum as background]
RT SQ	[Rotate and Shift - image, Quadratic interpolation ||]

USAGE

.OPERATION: RT C

.INPUT1 FILE: H_PIC001
[Enter the name of the file to be rotated.]

.OUTPUT FILE: H_IMG046
[Enter the name of the file where the rotated image is to be kept.]

.ROTATION ANGLE: 90.0
[Enter the rotation angle in degrees.]

[PIC001 will then be rotated 90 degrees, and the rotated image put in ROT001.]

.X-SHIFT:
[Enter the desired X location of the rotational center relative to the center of the image]

.Y-SHIFT:
[Enter the desired Y location of the rotational center]

NOTES

1. The rotation angle can be specified by reference to a register: '-X10' will input the rotation angle (with inverted sign) found in a previous 'OR X10' operation. Whether or not the sign has to be inverted follows from the order of argument files in 'OR'.

SUBROUTINES

ROT32

CALLER

UTIL3