module Ev3dev

You should install ImageMagick and its Ruby binding gem RMagick. robot@ev3dev:~$ sudo apt-get update robot@ev3dev:~$ sudo apt-get install ruby-rmagick (or ~$ sudo gem install rmagick -N -V)

www.ev3dev.org/docs/tutorials/using-ev3-lcd/ LCD Mode : 178 x 128 pixel

LineLength: 24 bytes (192 bits)
Geometry  : 1 (1 bit per pixel)
Type      : PACKED PIXELS
Visual    : MONO01 (0: white, 1: black)

Frame Buffer directory: /dev/fb0 Frame Buffer size : 24 * 128 = 3072 bytes 178 bits in a line (192 bits) and 128 rows are actually displayed

image_file must be 192 x 128 pixel .mono format (raw bi-level bitmap in least-significant-byte(LSB) first order) www.imagemagick.org/script/formats.php