This is the zSnapshot - Screenshot Plugin Thread
zSnapshot is a plugin to take and save screenshots with cross browser support.
The Screenshots resolution and aspect ratio can be chosen independent of the active screen,
they can get watermarked with images or text, and with krpano 1.20.1 or newer it is possible
to save high-resolution images.
zSnapshot does not provides an user interface or sharing functionality.
It is targeted at programmers wanting to implement their own user interface
without worrying about browser compatibility, canvas elements, blobs and file saving.
The screenshot format, proportion and pixel sizes can be limited or set to exact values.
There are no dependecies (jquery or other scripts) to include,
so zSnapshot is very simple and easy to use.
more infos below in this thread or on the plugin page :
https://krpano.com/plugins/userplugins/zsnapshot