COMPAR/WAVE

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:

$$W_j > \mbox{N\_Sigma}.\sigma_j$$

where $\sigma_j$ 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.