power_bytepower_bytePowerBytepower_bytePowerBytePowerByte (Operator)

Name

power_bytepower_bytePowerBytepower_bytePowerBytePowerByte — Return the power spectrum of a complex image.

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

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

Please note, that resulting gray values that exceed the value of 255 are clipped at 255 because of the resulting image type 'byte'"byte""byte""byte""byte""byte".

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 channel level.
Automatically parallelized on domain level.

Parameters

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

Input image in frequency domain.

PowerBytePowerBytePowerBytePowerBytePowerBytepowerByte (output_object) image(-array) → object (byte)

Power spectrum of the input image.

Example (C)

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

Result

power_bytepower_bytePowerBytepower_bytePowerBytePowerByte 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>)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_imageFftImagefft_imageFftImageFftImage, fft_genericfft_genericFftGenericfft_genericFftGenericFftGeneric, rft_genericrft_genericRftGenericrft_genericRftGenericRftGeneric, convol_fftconvol_fftConvolFftconvol_fftConvolFftConvolFft, convol_gaborconvol_gaborConvolGaborconvol_gaborConvolGaborConvolGabor

Possible Successors

disp_imagedisp_imageDispImagedisp_imageDispImageDispImage

Alternatives

abs_imageabs_imageAbsImageabs_imageAbsImageAbsImage, convert_image_typeconvert_image_typeConvertImageTypeconvert_image_typeConvertImageTypeConvertImageType, power_realpower_realPowerRealpower_realPowerRealPowerReal, power_lnpower_lnPowerLnpower_lnPowerLnPowerLn

Module

Foundation

Operators