power_ln power_ln PowerLn PowerLn (Operator)
Name
power_ln power_ln PowerLn PowerLn
— Return the power spectrum of a complex image.
Signature
Description
power_ln power_ln PowerLn PowerLn PowerLn
computes the power spectrum from the real and
imaginary parts of a Fourier-transformed image (see
fft_image fft_image FftImage FftImage FftImage
), 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:
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
Image Image Image Image image
(input_object) (multichannel-)image(-array) →
object HImage HImage Hobject (complex)
Input image in frequency domain.
ImageResult ImageResult ImageResult ImageResult imageResult
(output_object) image(-array) →
object HImage HImage Hobject * (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_ln power_ln PowerLn PowerLn PowerLn
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>)
.
If necessary, an exception is raised.
Possible Predecessors
fft_image fft_image FftImage FftImage FftImage
,
fft_generic fft_generic FftGeneric FftGeneric FftGeneric
,
rft_generic rft_generic RftGeneric RftGeneric RftGeneric
,
convol_fft convol_fft ConvolFft ConvolFft ConvolFft
,
convol_gabor convol_gabor ConvolGabor ConvolGabor ConvolGabor
Possible Successors
disp_image disp_image DispImage DispImage DispImage
,
convert_image_type convert_image_type ConvertImageType ConvertImageType ConvertImageType
,
scale_image scale_image ScaleImage ScaleImage ScaleImage
Alternatives
abs_image abs_image AbsImage AbsImage AbsImage
,
convert_image_type convert_image_type ConvertImageType ConvertImageType ConvertImageType
,
power_real power_real PowerReal PowerReal PowerReal
,
power_byte power_byte PowerByte PowerByte PowerByte
See also
fft_image fft_image FftImage FftImage FftImage
,
fft_generic fft_generic FftGeneric FftGeneric FftGeneric
,
rft_generic rft_generic RftGeneric RftGeneric RftGeneric
Module
Foundation