power_real

power_real ( Image : ImageResult : : )

Return the power spectrum of a complex image.

power_real computes the power spectrum from the real and imaginary parts of a Fourier-transformed image (see fft_image), i.e., the modulus of the frequencies. The result image is of type 'real'. The following formula is used:

  sqrt(real part**2 + imaginary part**2) .

Parameters

`Image` (input_object)	image(-array) `->` object : complex
Input image in frequency domain.

`ImageResult` (output_object)	image(-array) `->` object : real
Power spectrum of the input image.

Example (Syntax: C)

read_image(&Image,"affe");
disp_image(Image,WindowHandle);
fft_image(Image,&FFT);
power_real(FFT,&Power);
disp_image(Power,WindowHandle);

Result

power_real returns 2 (H_MSG_TRUE) if the image is of correct type. If the input is empty the behavior can be set via set_system(::'no_object_result',<Result>:). If necessary, an exception handling is raised.

Parallelization Information

power_real is reentrant and automatically parallelized (on tuple level, domain level).

Possible Predecessors

fft_image, fft_generic, rft_generic, convol_fft, convol_gabor

Possible Successors

disp_image, convert_image_type, scale_image

Alternatives

abs_image, convert_image_type, power_byte, power_ln

Module

Foundation