/usr/include/strigi/ is in libstreamanalyzer-dev 0.7.8-1ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/strigi/analysisresult.h
/usr/include/strigi/analyzerconfiguration.h
/usr/include/strigi/analyzerplugin.h
/usr/include/strigi/classproperties.h
/usr/include/strigi/diranalyzer.h
/usr/include/strigi/fieldproperties.h
/usr/include/strigi/fieldpropertiesdb.h
/usr/include/strigi/fieldtypes.h
/usr/include/strigi/filelister.h
/usr/include/strigi/indexeddocument.h
/usr/include/strigi/indexmanager.h
/usr/include/strigi/indexplugin.h
/usr/include/strigi/indexpluginloader.h
/usr/include/strigi/indexreader.h
/usr/include/strigi/indexwriter.h
/usr/include/strigi/query.h
/usr/include/strigi/queryparser.h
/usr/include/strigi/streamanalyzer.h
/usr/include/strigi/streamanalyzerfactory.h
/usr/include/strigi/streamendanalyzer.h
/usr/include/strigi/streameventanalyzer.h
/usr/include/strigi/streamlineanalyzer.h
/usr/include/strigi/streamsaxanalyzer.h
/usr/include/strigi/streamthroughanalyzer.h
/usr/include/strigi/strigi_thread.h
/usr/include/strigi/variant.h