Everybody knows the site Gravatar : http://en.gravatar.com/

Basically with some email address is possible to upload a Picture which will be stored in multiple resolutions and generate a MD5 Hash that can be referenced to show/display with specific width and height.

http://emn178.github.io/online-tools/sha256.html

I wonder if there is a way to call a function to resize and uploaded JPG to be saved for example in High, Medium, Small , Very Small  and Icon resolution to be used to display the picture of lets said the authenticated user. 

This will be used as Icon for all their Forms. or when they participate in some approval process, who knows like a Digital Sigature stamped when they click approve.

Any ideas ???