<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <!--Converted with LaTeX2HTML 98.1p1 release (March 2nd, 1998) originally by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds * revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan * with significant contributions from: Jens Lippmann, Marek Rouchal, Martin Wilck and others --> <HTML> <HEAD> <TITLE>COMPAR/WAVE</TITLE> <META NAME="description" CONTENT="COMPAR/WAVE"> <META NAME="keywords" CONTENT="vol2"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> <LINK REL="STYLESHEET" HREF="vol2.css"> <LINK REL="next" HREF="node361.html"> <LINK REL="previous" HREF="node359.html"> <LINK REL="up" HREF="node346.html"> <LINK REL="next" HREF="node361.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html5947" HREF="node361.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html5944" HREF="node346.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html5938" HREF="node359.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html5946" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="icons.gif/contents_motif.gif"></A> <BR> <B> Next:</B> <A NAME="tex2html5948" HREF="node361.html">PLOT/SNR</A> <B> Up:</B> <A NAME="tex2html5945" HREF="node346.html">Commands Description</A> <B> Previous:</B> <A NAME="tex2html5939" HREF="node359.html">FILTER/WAVE</A> <BR> <BR> <!--End of Navigation Panel--> <H3><A NAME="SECTION0020921400000000000000"> COMPAR/WAVE</A> </H3> <DIV ALIGN="CENTER"> COMPAR/WAVE Imag_1 Imag_2 [N_Scal] [N_Sigma] [T_Cor] [T_Snr] [Disp] [Init] </DIV> Compares two images in the wavelet space (see section <A HREF="node334.html#sec_comp">14.7</A>). At each scale the signal to noise ratio and the correlation is calculated. The results are stored in tables <EM>T_Cor</EM> and <EM>Tab_Snr</EM> (the default names for the two tables are ``cmp_correl.tbl'' and ``cmp_snr.tbl''). <EM>N_Scal</EM> defines the number of scales for the wavelet transform (default is 3). <EM>N_Sigma</EM> is a parameter which allows us to select the wavelet coefficients which are taken into account in the comparison. Only the wavelet coefficients <I>W</I><SUB><I>j</I></SUB> of the first image who verifies the following relation are taken into account: <BR><P></P> <DIV ALIGN="CENTER"> <!-- MATH: \begin{displaymath} W_j > \mbox{N\_Sigma}.\sigma_j \end{displaymath} --> <IMG WIDTH="165" HEIGHT="41" SRC="img885.gif" ALT="\begin{displaymath}W_j > \mbox{N\_Sigma}.\sigma_j\end{displaymath}"> </DIV> <BR CLEAR="ALL"> <P></P> where <IMG WIDTH="28" HEIGHT="39" ALIGN="MIDDLE" BORDER="0" SRC="img886.gif" ALT="$\sigma_j$"> is the standard deviation of the scale <I>j</I>. The default value is 0, this means that all the wavelet coefficients are used. If <EM>Disp</EM> 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 <EM>Init</EM> equal to <I>Y</I>, the tables <EM>T_Cor</EM> and <EM>Tab_Snr</EM> are initialized, and if <EM>Init</EM> equal to N, columns are added to the tables. That allows us to compare several images to a reference image. <P> <HR> <!--Navigation Panel--> <A NAME="tex2html5947" HREF="node361.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html5944" HREF="node346.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html5938" HREF="node359.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html5946" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="icons.gif/contents_motif.gif"></A> <BR> <B> Next:</B> <A NAME="tex2html5948" HREF="node361.html">PLOT/SNR</A> <B> Up:</B> <A NAME="tex2html5945" HREF="node346.html">Commands Description</A> <B> Previous:</B> <A NAME="tex2html5939" HREF="node359.html">FILTER/WAVE</A> <!--End of Navigation Panel--> <ADDRESS> <I>Petra Nass</I> <BR><I>1999-06-15</I> </ADDRESS> </BODY> </HTML>