find /otrs_attachment_files/2013/10/15/ -type f \( -name "*.png" -o -name "*.jpg" \) -exec cp -ar {} /root/otrs_test_filebackup \;
rsync -am --include='*.png' --include='*.jpg' --include='*/' --exclude='*' /otrs_attachment_files/2013/10/15/ /root/otrs_test_filebackup
find ... | cpio -p TARGETDIR
if you don't have cpio, many archieving tools including tar and pax (likely available) can be used, but that would actually create a temorary archieve with a possibly large performance hit
cd TARGETDIR ; find ... | tar -c -f- | tar -x -f-
some versions of xargs can replace tokens several times ( and you can add -P for parallel processing ) but this spawns one command per file
find ... | xargs -J% cp % TARGETDIR/%
likewise in shell scripting (yes the double-double quotes work)
find ... | while read path
do mkdir -p "`dirname "TARGETDIR/$path"`"
cp "$path" "TARGETDIR/$path"
done