<!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>Classification of images</TITLE> <META NAME="description" CONTENT="Classification of images"> <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="node381.html"> <LINK REL="previous" HREF="node379.html"> <LINK REL="up" HREF="node378.html"> <LINK REL="next" HREF="node381.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html6186" HREF="node381.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html6183" HREF="node378.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html6177" HREF="node379.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html6185" 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="tex2html6187" HREF="node381.html">An example of a</A> <B> Up:</B> <A NAME="tex2html6184" HREF="node378.html">Classification of Images</A> <B> Previous:</B> <A NAME="tex2html6178" HREF="node379.html">Creation of the Classification</A> <BR> <BR> <!--End of Navigation Panel--> <H2><A NAME="SECTION002242000000000000000"> Classification of images</A> </H2> The classification process (command CLASSIFY/IMAGE) tags each frame with one or more character strings supplied by the user that classify the image in a unique way and will be stored into columns of the OST. For instance scientific exposures observed in SUSI using the filter number 639 may be described` with the two strings ``SCI" and ``FILT_639". The practical problem is however that the very large number of different possible optical elements mounted on instruments like EMMI/SUSI is not fixed in advance; for example, filters may be added or changed. Clearly, one do not want to write classification rules for all filter numbers or all combinations of grisms and gratings. <BR> We have for those reasons introduced the concept of ``<I>Wild Card Replacement Character</I>"; This character & may be used to build the output classification string in the following way: <I>substring</I>&<I>n</I> will be built by finding the <I>n-th</I> occurrence of the <IMG WIDTH="40" HEIGHT="54" ALIGN="BOTTOM" BORDER="0" SRC="img897.gif" ALT="$\ast$"> character in the classification rule, reading the content of the corresponding column and appending it to <I>substring</I>. <BR> <DIV ALIGN="CENTER"><A NAME="17428"> </A> <TABLE> <CAPTION><STRONG>Table 15.5:</STRONG> MIDAS session for classifying SUSI exposures</CAPTION> <TR><TD> <DIV ALIGN="CENTER"> <TABLE CELLPADDING=3 BORDER="1"> <TR><TD ALIGN="LEFT">Midas 001> CREATE/CRULE susi_ost BIAS</TD> </TR> <TR><TD ALIGN="LEFT"><TT> <FONT SIZE="-2">.. The Table Editor is invoked .. </TT></FONT></TD> </TR> <TR><TD ALIGN="LEFT">Midas 002> READ/DESCR susi_ost.tbl BIAS</TD> </TR> <TR><TD ALIGN="LEFT"><B><FONT SIZE="-2"> :IDENT.EQ."*BIAS*".AND.:EXPTIME.LE.1</FONT></B></TD> </TR> <TR><TD ALIGN="LEFT">Midas 003> CREATE/CRULE susi_ost FF</TD> </TR> <TR><TD ALIGN="LEFT"><TT> <FONT SIZE="-2">.. The Table Editor is invoked .. </TT></FONT></TD> </TR> <TR><TD ALIGN="LEFT">Midas 004> READ/DESCR susi_ost.tbl FF</TD> </TR> <TR><TD ALIGN="LEFT"><B> <FONT SIZE="-2">:IDENT.EQ."FF*"</B> </FONT></TD> </TR> <TR><TD ALIGN="LEFT">Midas 005> CREATE/CRULE susi_ost SCI</TD> </TR> <TR><TD ALIGN="LEFT"><TT> <FONT SIZE="-2">.. The Table Editor is invoked .. </TT></FONT></TD> </TR> <TR><TD ALIGN="LEFT">Midas 006> READ/DESCR susi_ost.tbl SCI</TD> </TR> <TR><TD ALIGN="LEFT"><B> <FONT SIZE="-2">:IDENT.NE."*BIAS*".AND.:IDENT.NE."*FF*"</B> </FONT></TD> </TR> <TR><TD ALIGN="LEFT">Midas 007> CLASSIFY/IMAGE susi_ost BIAS EXPTYPE BIAS</TD> </TR> <TR><TD ALIGN="LEFT">Midas 008> CLASSIFY/IMAGE susi_ost FF EXPTYPE FF</TD> </TR> <TR><TD ALIGN="LEFT">Midas 009> CLASSIFY/IMAGE susi_ost SCI EXPTYPE SCI</TD> </TR> <TR><TD ALIGN="LEFT">Midas 010> CREATE/CRULE susi_ost OPATH</TD> </TR> <TR><TD ALIGN="LEFT"><TT> <FONT SIZE="-2">.. The Table Editor is invoked .. </TT></FONT></TD> </TR> <TR><TD ALIGN="LEFT">Midas 011> READ/DESCR susi_ost.tbl OPATH</TD> </TR> <TR><TD ALIGN="LEFT"><B> <FONT SIZE="-2">:FILTER_NO.EQ."#*".AND.:FILTER_TYPE.EQ."FILTER*"</B> </FONT></TD> </TR> <TR><TD ALIGN="LEFT">Midas 012> CLASSIFY/IMAGE susi_ost OPATH OPATH FILT_&1</TD> </TR> </TABLE></DIV> <A NAME="midasproc"> </A></TD></TR> </TABLE> </DIV> <BR> <P> Suppose you have created the classification rule WFIB for flagging all exposures obtained in the blue arm of EMMI using the wide-field imaging mode. Now you want to flag these exposures with a character string containing the filter number that has been used. <BR> The corresponding descriptor WFIB of the OST may in natural language be: ``frame exposed in the blue arm using any filter and no grating" The translated selected criterion looks as follows: <BR><BLOCKQUOTE> <TT>:FILTB_ID.EQ."*".AND.:FILTB_TYP.EQ."FILTER*".AND.:GRATB_ID.EQ.""</TT></BLOCKQUOTE> <P> The command <BLOCKQUOTE> <TT>CLASSIFY/IMAGE ntt WFIB :OPATH FB&1</TT></BLOCKQUOTE>will flag all files in the OST ntt which satisfy this selection criterion and will store in the column :OPATH the character string obtained by appending the contents of column :FILTB_ID to the string FB. The classification given in the column :OPATH is obviously more convenient to use than the original selection criteria. <BR> <TT>Note: <BR> This implementation of the sofware expects, for the association process, that the type of the exposures is stored in a column labeled :EXPTYPE and that frames classified as scientific exposures are flagged with the string SCI.</TT> <P> <HR> <!--Navigation Panel--> <A NAME="tex2html6186" HREF="node381.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html6183" HREF="node378.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html6177" HREF="node379.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html6185" 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="tex2html6187" HREF="node381.html">An example of a</A> <B> Up:</B> <A NAME="tex2html6184" HREF="node378.html">Classification of Images</A> <B> Previous:</B> <A NAME="tex2html6178" HREF="node379.html">Creation of the Classification</A> <!--End of Navigation Panel--> <ADDRESS> <I>Petra Nass</I> <BR><I>1999-06-15</I> </ADDRESS> </BODY> </HTML>