Image Plotting in Script Module

local f=io.open(filename,'rb')
f:seek('set',18)
local y=string.byte(f:read(1))+string.byte(f:read(1))*256+string.byte(f:read(1))*65536+string.byte(f:read(1))*16777216
local x=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',54)
local r,g,b=0,0,0
for j=0,x-1 do
 for i=0,y-1 do
  b,g,r=string.byte(f:read(1)),string.byte(f:read(1)),string.byte(f:read(1))
  if i<612 and x-j<380 and(not(r==0 and g==0 and b==0)) then
   tpt.create(i,x-j,elemtype)
   tpt.set_property('dcolour',r*65536+g*256+b+16777216*255,i,x-j)
   tpt.set_property(proptype,(r + g + b),i,x-j)
   if scale > 0  then
    tpt.set_property(proptype,(r + g + b) * scale,i,x-j)
end
end
  end
 end
 for i=1,y%4 do f:read(1) end
f:close()