How to generate a collage image like shown

Question

How to generate a collage image like show below. I would appreciate if you can let me know if there are any online tools or apps which do this. Thanks!

Answer 1

Use ImageMagick montage like this to get your montage 10 images wide and with all images abutted together with no space between:

montage -geometry +0+0 -tile 10x *.jpg result.jpg

My images repeat because I didn't bother finding 1,000 unique faces :-)