Good question, we don't have a facility to support this directly at the moment, but it could be added.
If you are not in a hurry, you can save your image to microSD and then use jevois command fileget from the host to get that file. If you are in a hurry (need low latency), you should transmit the image over the USB video link, which is the default (UVC protocol).
The file transfer stuff is largely undocumented at this stage, though, as it has been reserved for internal use by the JeVois Inventor only.
The basic protocol is as follows:
host sends: fileget /path/to/file
jevois replies: JEVOIS_FILEGET N\n<raw data>
where N is the file size (written out as an ascii string). The raw data sent has exactly that size, then we switch back to command-line interpreter mode.
See here for the jevois side: http://jevois.org/doc/Serial_8C_source.html function fileGet()
and in the inventor we implement the host side: https://github.com/jevois/jevois-inventor/blob/master/Serial.C look for JobFileGet (line 335 and beyond, at the time of this writing).
note that the \n after the size value could be a \r\n depending on user preferences, so the receiver should be able to tolerate that.