-- a jittering filter implemented in lua

edge_duplicate=1 -- set edge wrap behavior to use nearest valid sample

function jitter(amount)
  local x,y
  var2=var1
  for y = 0, height-1 do
    for x = 0, width-1 do
      local nx,ny
      local r,g,b,a
      nx=x+(math.random()-0.5)*amount
      ny=y+(math.random()-0.5)*amount
      r,g,b,a=get_rgba(nx,ny)
      set_rgba(x,y, r,g,b,a)
    end
    progress(y/height)
  end
end

jitter(10)