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topolar stsdas.analysis.fourier



topolar -- Convert from real and imaginary parts to amplitude and phase.


topolar input ampl phase


This task takes a pair of images, real and imaginary parts of a Fourier transform, and converts them to the amplitude and phase. As with other tasks in the fourier package, the names of the real and imaginary parts are produced by appending "r" and "i" respectively to the name specified by the parameter input. For each pixel, the amplitude is the square root of the sum of the squares of the real and imaginary parts, and the phase is the arctangent: ATAN2 (imaginary, real). The phase is in radians within the interval (-pi,+pi).


input = "" [file name]
Name of the input image.

The letters "r" and "i" will be appended to the name to form the names of the images for real and imaginary parts respectively. It is an error if either the real or imaginary part does not exist.

ampl = "" [file name]
Name of the output image for the amplitude.
phase = "" [file name]
Name of the output image for the phase.


1. Converts real part x00w6601rr.d0h and imaginary part x00w6601ri.d0h to amplitude a.hhh and phase ph.hhh.

     fo> topolar x00w6601r.d0h a.hhh ph.hhh




Type "help fourier option=sys" for a higher-level description of the fourier package.

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