scanimage does not find scanner unless sudo'ed, but shows up with sane-find-scanner (Raspbian)

Solved my problem, thanks to the tutorial found here:

http://www.johndstech.com/2016/linux/raspberry-pi/geek-friday-setting-up-epson-scanning-on-raspberry-pi/

I had to create /etc/udev/rules.d/55-libsane.rules to say:

SYSFS{idVendor}=="04b8", MODE="0666", GROUP="scanner", ENV{libsane_matched}="yes"

and /etc/saned/epson2.conf to reflect the vendor and product ID:

usb <0x04b8> <0x0839>