dialog "bmp",16
picload refstr
repeat winx*winy
pget x,y
r=rval
g=gval
b=bval
;明るさ＝Ｒ×0.30＋Ｇ×0.59＋Ｂ×0.11
a=((r*30)+(g*59)+(b*11))/100
color a,a,a
pset x,y
x++
if x=winx:y++:x=0
loop
stop