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_lnPowerLnPowerLnPowerLnpower_ln computes the power spectrum from the real and imaginary parts of a Fourier-transformed image (see fft_imagefft_imageFftImageFftImageFftImagefft_image), i.e., the modulus of the frequencies. Additionally, the natural logarithm is applied to the result. The result image is of type 'real'"real""real""real""real""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

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

Input image in frequency domain.

ImageResultImageResultImageResultImageResultimageResultimage_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_lnPowerLnPowerLnPowerLnpower_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>:)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)set_system("no_object_result",<Result>). If necessary, an exception is raised.

Possible Predecessors

fft_imagefft_imageFftImageFftImageFftImagefft_image, fft_genericfft_genericFftGenericFftGenericFftGenericfft_generic, rft_genericrft_genericRftGenericRftGenericRftGenericrft_generic, convol_fftconvol_fftConvolFftConvolFftConvolFftconvol_fft, convol_gaborconvol_gaborConvolGaborConvolGaborConvolGaborconvol_gabor

Possible Successors

disp_imagedisp_imageDispImageDispImageDispImagedisp_image, convert_image_typeconvert_image_typeConvertImageTypeConvertImageTypeConvertImageTypeconvert_image_type, scale_imagescale_imageScaleImageScaleImageScaleImagescale_image

Alternatives

abs_imageabs_imageAbsImageAbsImageAbsImageabs_image, convert_image_typeconvert_image_typeConvertImageTypeConvertImageTypeConvertImageTypeconvert_image_type, power_realpower_realPowerRealPowerRealPowerRealpower_real, power_bytepower_bytePowerBytePowerBytePowerBytepower_byte

Module

Foundation

Operators