energy_gaborenergy_gaborEnergyGaborenergy_gaborEnergyGaborEnergyGabor (Operator)

Name

energy_gaborenergy_gaborEnergyGaborenergy_gaborEnergyGaborEnergyGabor — Calculate the energy of a two-channel image.

Signature

energy_gabor(ImageGabor, ImageHilbert : Energy : : )

energy_gaborenergy_gaborEnergyGaborenergy_gaborEnergyGaborEnergyGabor calculates the local contrast (EnergyEnergyEnergyEnergyEnergyenergy) 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_gaborconvol_gaborConvolGaborconvol_gaborConvolGaborConvolGabor). In this case, the first channel of the image passed to energy_gaborenergy_gaborEnergyGaborenergy_gaborEnergyGaborEnergyGabor is the Gabor-filtered image, transformed back into the spatial domain (see fft_image_invfft_image_invFftImageInvfft_image_invFftImageInvFftImageInv), 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.

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

ImageGaborImageGaborImageGaborImageGaborImageGaborimageGabor (input_object) (multichannel-)image(-array) → object (byte / real)

1st channel of input image (usually: Gabor image).

ImageHilbertImageHilbertImageHilbertImageHilbertImageHilbertimageHilbert (input_object) (multichannel-)image(-array) → object (byte / real)

2nd channel of input image (usually: Hilbert image).

EnergyEnergyEnergyEnergyEnergyenergy (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_gaborenergy_gaborEnergyGaborenergy_gaborEnergyGaborEnergyGabor 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>:)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

gen_gaborgen_gaborGenGaborgen_gaborGenGaborGenGabor, convol_gaborconvol_gaborConvolGaborconvol_gaborConvolGaborConvolGabor, fft_image_invfft_image_invFftImageInvfft_image_invFftImageInvFftImageInv

Module

Foundation

Operators