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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 Wj of the first image who verifies the following relation are taken into account:

\begin{displaymath}W_j > \mbox{N\_Sigma}.\sigma_j\end{displaymath}

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.


next up previous contents
Next: PLOT/SNR Up: Commands Description Previous: FILTER/WAVE
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1999-06-15