Add timestamp to photo using ImageMagick

rem dptnt.com/2009/04/how-to-add-date-time-stamp-to-jpeg-photos-using-free-software/
 
@ECHO OFF
SETLOCAL
FOR /R %%G IN (*.jpg) DO CALL :process "%%G"
GOTO :end
 
:process
 SET _inname=%1
 identify -format %%w %_inname% >dttmpfile
 set /p width=<dttmpfile
 Set /a pointsize=%width%/50
rem  echo ZZ >> dttempfile
 DEL dttmpfile
 ECHO Processing %_inname% ...
 convert %_inname% -gravity SouthEast -font Arial -pointsize %pointsize% -fill orange -annotate +%pointsize%+%pointsize% "%%[exif:DateTimeOriginal]" %_inname%
 EXIT /B
:end