# set terminal pngcairo  background "#ffffff" font "arial,10" fontscale 1.0 size 500, 300 
# set output 'image.4.png'
unset key
set label 1 "\"This picture was taken by my friend Ansel Adams.\"" at 63, 140, 0 centre norotate back nopoint offset character 0, 0, 0
set xtics border out scale 1,0.5 mirror norotate  offset character 0, 0, 0 autojustify
set ytics border out scale 1,0.5 mirror norotate  offset character 0, 0, 0 autojustify
set ztics border out scale 1,0.5 nomirror norotate  offset character 0, 0, 0 autojustify
set cbtics border out scale 1,0.5 mirror norotate  offset character 0, 0, 0 autojustify
set rtics axis out scale 1,0.5 nomirror norotate  offset character 0, 0, 0 autojustify
set title "The palette can be changed from color to gray scale" 
set xrange [ -10.0000 : 137.000 ] noreverse nowriteback
set yrange [ -10.0000 : 157.000 ] noreverse nowriteback
set palette positive nops_allcF maxcolors 0 gamma 1.5 gray
unset colorbox
plot 'blutux.rgb' binary array=(128,128) flipy format='%uchar%uchar%uchar' using ($1+$2+$3)/3 with image