set term pngc enh font "Times,10" size 480,480
set out "raw.png"
set border lc rgb "gray30"
unset key
set xtics 129,2
set ytics 31,2
set grid  front
x0=128; x1=150; y0=29.5; y1=46.2
set object rect from x0,y0 to x1,y1 fs noborder fc rgb "web-blue" behind 

plot [x0:x1] [y0:y1] "world_50m.txt" w filledc lc rgb "khaki"

! display raw.png