COMPAR/WAVE Imag_1 Imag_2 [N_Scal] [N_Sigma] [T_Cor] [T_Snr] [Disp] [Init]
Compares two images in the wavelet space (see section
). At each scale the signal to noise ratio and the
correlation is calculated. The results are stored in tables
T_Cor and Tab_Snr (the default names for the two tables are
``cmp_correl.tbl'' and ``cmp_snr.tbl''). N_Scal defines the
number of scales for the wavelet transform (default is 3).
N_Sigma is a parameter which allows us to select the wavelet
coefficients which are taken into account in the comparison. Only the
wavelet coefficients 
of the first image who verifies the
following relation are taken into account:
where 
is the standard deviation of the scale j.
The default value is 0, this means that all the wavelet coefficients are used.
If Disp equal to Y (yes), the results are plotted in two graphics
window (Y is the default value) by calling the two procedures PLOT/COR
and PLOT/SNR. If Init equal to Y, the tables
T_Cor and Tab_Snr are initialized, and if Init equal to N,
columns are added to the tables. That allows us to compare several images
to a reference image.