Calculate the energy of a two-channel image.
energy__ calculates the local contrast (Energy) of the two input images. The energy of the resulting image is then defined as berechnet den lokalen Kontrast energy = channel1 ^2 + channel2 ^2 . 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__ is the Gabor-filtered image, transformed back into the spatial domain (see fft_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.
ImageGabor (input_object) |
image(-array) -> object : byte / real |
1st channel of input image (usually: Gabor image). |
ImageHilbert (input_object) |
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. |
fft__(Image,&FFT); gen_gabor(&Filter,1.4,0.4,1.0,1.5,512); convol_gabor__(FFT,Filter,&Gabor,&Hilbert); fft_inv__(Gabor,&GaborInv); fft_inv__(Hilbert,&HilbertInv); energy__(GaborInv,HilbertInv,&Energy);
energy__ returns TRUE if all parameters are correct. If the input is empty the behaviour can be set via set_system(::'no_object_result',<Result>:). If necessary, an exception is raised.
gen_gabor, convol_gabor__, fft_inv__