Resize
gm convert -strip -resize $RESIZE -define jpeg:preserve-settings $INPUT $TMPIMG
Watermark
gm convert -size $(gm identify -format %wx%h $TMPIMG) xc:none -pointsize 12 -font helvetica -gravity southeast -fill "#000" -draw "text 10,10 '$TEXT'" -fill "#fff" -draw "text 11,10 '$TEXT'" png:-