Name

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GAL_FLAT

Purpose

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Transforms the image of a galaxy so that the galaxy appears face-on

Explanation

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Either a nearest-neighbor approximations or a bilinear interpolation
may be used.

Calling Sequence

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RESULT = GAL_FLAT( image, ang, inc, [, cen, /INTERP ] )

Inputs

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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

Optional Inputs

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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

Input Keywords

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INTERP - If present, and non-zero, then bilinear interpolation will be
performed. Otherwise a nearest neighbor approximation is used.

Outputs

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RESULT - the transformed image, same dimensions and type as IMAGE

Method

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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.

Revision History

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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