convert tmp/mkgrid.40680.croppx.gif -fill black -draw "line 0,0 0,928" -draw "line 50,0 50,928" -draw "line 100,0 100,928" -draw "line 150,0 150,928" -draw "line 200,0 200,928" -draw "line 250,0 250,928" -draw "line 300,0 300,928" -draw "line 350,0 350,928" -draw "line 400,0 400,928" -draw "line 450,0 450,928" -draw "line 500,0 500,928" -draw "line 0,0 534,0" -draw "line 0,50 534,50" -draw "line 0,100 534,100" -draw "line 0,150 534,150" -draw "line 0,200 534,200" -draw "line 0,250 534,250" -draw "line 0,300 534,300" -draw "line 0,350 534,350" -draw "line 0,400 534,400" -draw "line 0,450 534,450" -draw "line 0,500 534,500" -draw "line 0,550 534,550" -draw "line 0,600 534,600" -draw "line 0,650 534,650" -draw "line 0,700 534,700" -draw "line 0,750 534,750" -draw "line 0,800 534,800" -draw "line 0,850 534,850" -draw "line 0,900 534,900" mkgrid.jpg