proc read_jpg_comment {file} {
set fh [open $file r]
fconfigure $fh -encoding binary -translation binary -eofchar {}
if {[read $fh 2] != "\xFF\xD8"} { close $fh; return }
set c 0
while {$c != "\xDA"} {
while {[set c [read $fh 1]] != "\xFF" && $c != ""} {}
while {[set c [read $fh 1]] == "\xFF"} {}
binary scan [read $fh 2] cc l1 l2
set len [expr {$l1<<8|$l2}]
if {$c == "\xFE"} {
set com [read $fh [expr {$len - 2}]]
close $fh
return $com
} elseif {$c == "" || $len < 2} {
break
} else {
seek $fh [expr {$len - 2}] current
}
}
close $fh
}--AF