How to add watermark to 300 photos in 150 seconds ?

Mass edited all photos quickly and easily using “Image Magic” program in terminal (Aka command prompt)

sudo apt-get install imagemagick

Copy all photos into a folder , and resized them by this command:

mogrify -resize 65% *.jpg

Then add the watermark to all of photos using this command :

mogrify -font /usr/share/fonts/truetype/msttcorefonts/Arial_Black.ttf pointsize 22 -verbose -draw “gravity south fill black text 0,33 ‘Focused On The Unfocused’ fill white text 1,32 ‘Focused On The Unfocused’ ” *.jpg

Note that you should give the program the address to font file on your system , (I have marked it in green) to find the Arial font’s address on my ubuntu system I used this command :
locate Arial*.*

source: http://blog.shevin.info