Operator Reference
energy_gabor (Operator)
energy_gabor
— Calculate the energy of a two-channel image.
Signature
energy_gabor(ImageGabor, ImageHilbert : Energy : : )
Description
energy_gabor
calculates the local contrast
(Energy
) of the two input images. The energy of the
resulting image is then defined as
Often the calculation of the energy is preceded by the convolution
of an image with a Gabor filter and the Hilbert transform of the
Gabor filter (see convol_gabor
). In this case, the
first channel of the image passed to energy_gabor
is the
Gabor-filtered image, transformed back into the spatial domain (see
fft_image_inv
), and the second channel the result of the
convolution with the Hilbert transform, also transformed back into
the spatial domain. The local energy is a measure for the local
contrast of structures (e.g., edges and lines) in the image.
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
ImageGabor
(input_object) (multichannel-)image(-array) →
object (byte / real)
1st channel of input image (usually: Gabor image).
ImageHilbert
(input_object) (multichannel-)image(-array) →
object (byte / real)
2nd channel of input image (usually: Hilbert image).
Energy
(output_object) image(-array) →
object (real)
Image containing the local energy.
Example (C)
fft_image(Image,&FFT); gen_gabor(&Filter,1.4,0.4,1.0,1.5,512); convol_gabor(FFT,Filter,&Gabor,&Hilbert); fft_image_inv(Gabor,&GaborInv); fft_image_inv(Hilbert,&HilbertInv); energy_gabor(GaborInv,HilbertInv,&Energy);
Result
energy_gabor
returns 2 (
H_MSG_TRUE)
if all parameters are correct.
If the input is empty the behavior can be set via
set_system(::'no_object_result',<Result>:)
. If
necessary, an exception is raised.
Possible Predecessors
gen_gabor
,
convol_gabor
,
fft_image_inv
Module
Foundation