Powder Toy image plotting with QRTZ

function qrtz(filename)
elemtype = 'qrtz'
local f=io.open(filename,'rb')
f:seek('set',20)
local width=string.byte(f:read(1))+string.byte(f:read(1))*256+string.byte(f:read(1))*65536+string.byte(f:read(1))*16777216
local height=string.byte(f:read(1))+string.byte(f:read(1))*256+string.byte(f:read(1))*65536+string.byte(f:read(1))*16777216
f:seek('set',50)
local red,green,blue=0,0,0
for j=0,height-1 do
 for i=0,width-1 do
  blue,green,red=string.byte(f:read(1)),string.byte(f:read(1)),string.byte(f:read(1))
  if i<612 and height-j<380 then
   tpt.create(i,height-j,elemtype)
   tpt.set_property('tmp',((red+green+blue)*.013071895),i,height-j)
 tpt.set_property('life',((red+green+blue)*.013071895),i,height-j) -- No, life doesn't affect the color unless you change the element, but now you can change the element :)
  end
 end
 for i=1,width%4 do f:read(1) end
end
f:close()
end