# set terminal pngcairo  background "#ffffff" font "arial,10" fontscale 1.0 size 500, 300 
# set output 'image2.5.png'
set title "Simple extension of a two dimensional image into three dimensions" 
set xrange [ -10.0000 : 137.000 ] noreverse nowriteback
set yrange [ -10.0000 : 157.000 ] noreverse nowriteback
set cbrange [ 0.00000 : 255.000 ] noreverse nowriteback
splot 'blutux.rgb' binary array=(128,128) flip=y format='%uchar%uchar%uchar' using ($1+$2+$3)/3 with image