> collections.  However to enable image content based queries to be made
> using SRW the draft specifications were extended where necessary
> (notably the CQL language).

Why?

Just use XCQL and change the encoding type of the <term> field from
string to base64 as per the recommended XSI type and send the image in the
query.

eg:
<query>
  <index>artiste.imageBinary</index>
  <relation> Relevance </relation>
  <term xsi:type="base64">A8205sakjaf1fjaskd...</term>
</query>

Rob

--
      ,'/:.          Rob Sanderson ([log in to unmask])
    ,'-/::::.        http://www.o-r-g.org/~azaroth/
  ,'--/::(@)::.      Special Collections and Archives, extension 3142
,'---/::::::::::.    Twin Cathedrals:  telnet: liverpool.o-r-g.org 7777
____/:::::::::::::.              WWW:  http://liverpool.o-r-g.org:8000/
I L L U M I N A T I