power_lnpower_lnPowerLnPowerLnpower_ln (Operator)

Name

power_lnpower_lnPowerLnPowerLnpower_ln — Return the power spectrum of a complex image.

Signature

power_ln(Image : ImageResult : : )

Description

power_lnpower_lnPowerLnPowerLnpower_ln computes the power spectrum from the real and imaginary parts of a Fourier-transformed image (see fft_imagefft_imageFftImageFftImagefft_image), i.e., the modulus of the frequencies. Additionally, the natural logarithm is applied to the result. The result image is of type real. The following formula is used:

Execution Information

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Automatically parallelized on tuple level.
Automatically parallelized on channel level.
Automatically parallelized on domain level.

Parameters

ImageImageImageimageimage (input_object) (multichannel-)image(-array) → object (complex)

Input image in frequency domain.

ImageResultImageResultImageResultimageResultimage_result (output_object) image(-array) → object (real)

Power spectrum of the input image.

Example (C)

read_image(&Image,"monkey");
disp_image(Image,WindowHandle);
fft_image(Image,&FFT);
power_ln(FFT,&Power);
disp_image(Power,WindowHandle);

Result

power_lnpower_lnPowerLnPowerLnpower_ln 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 is raised.