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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
14.7). 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 *W*_{j} 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.

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*Petra Nass*

*1999-06-15*