Transforms the image of a galaxy so that the galaxy appears face-on
Either a nearest-neighbor approximations or a bilinear interpolation
may be used.
RESULT = GAL_FLAT( image, ang, inc, [, cen, /INTERP ] )
IMAGE - Image to be transformed
ANG - Angle of major axis, counterclockwise from Y-axis, degrees
For an image in standard orientation (North up, East left)
this is the Position Angle
INC - Angle of inclination of galaxy, degrees
CEN - Two element vector giving the X and Y position of galaxy center
If not supplied, then the galaxy center is assumed to coincide
with the image center
INTERP - If present, and non-zero, then bilinear interpolation will be
performed. Otherwise a nearest neighbor approximation is used.
RESULT - the transformed image, same dimensions and type as IMAGE
A set of 4 equal spaced control points are corrected for inclination
using the procedure POLYWARP. These control points are used by
POLY_2D to correct the whole image.
Written by R. S. Hill, SASC Technologies Inc., 4 December 1985
Code cleaned up a bit W. Landsman December 1992
Converted to IDL V5.0 W. Landsman September 1997