power_lnpower_lnpower_lnPowerLnPowerLn (Operator)

Name

power_lnpower_lnpower_lnPowerLnPowerLn — Return the power spectrum of a complex image.

Signature

Description

power_lnpower_lnpower_lnPowerLnPowerLn computes the power spectrum from the real and imaginary parts of a Fourier-transformed image (see fft_imagefft_imagefft_imageFftImageFftImage), 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". The following formula is used:

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

Parallelization

• 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 domain level.

Parameters

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

Possible Predecessors

fft_imagefft_imagefft_imageFftImageFftImage, fft_genericfft_genericfft_genericFftGenericFftGeneric, rft_genericrft_genericrft_genericRftGenericRftGeneric, convol_fftconvol_fftconvol_fftConvolFftConvolFft, convol_gaborconvol_gaborconvol_gaborConvolGaborConvolGabor

Possible Successors

disp_imagedisp_imagedisp_imageDispImageDispImage, convert_image_typeconvert_image_typeconvert_image_typeConvertImageTypeConvertImageType, scale_imagescale_imagescale_imageScaleImageScaleImage

Alternatives

abs_imageabs_imageabs_imageAbsImageAbsImage, convert_image_typeconvert_image_typeconvert_image_typeConvertImageTypeConvertImageType, power_realpower_realpower_realPowerRealPowerReal, power_bytepower_bytepower_bytePowerBytePowerByte

See also

fft_imagefft_imagefft_imageFftImageFftImage, fft_genericfft_genericfft_genericFftGenericFftGeneric, rft_genericrft_genericrft_genericRftGenericRftGeneric

Module

Foundation