i, j, x1, y1, x2, y2 = string.find(result, "(%d+),%s*(%d+),%s*(%d+),%s*(%d+)")

-- copy image

w, h = img.width, img.height
pixels = {}
for y = 0, h-1 do
  for x = 0, w-1 do
    pixels[y*w+x+1] = img.getInt(x, y)
  end
end

-- paint rectangle

x1, y1 = x1-1, y1-1 -- paint AROUND the found image

for y = y1, y2 do
  pixels[y*w+x1+1] = 0xFF0000
  pixels[y*w+x2+1] = 0xFF0000
end

for x = x1, x2 do
  pixels[y1*w+x+1] = 0xFF0000
  pixels[y2*w+x+1] = 0xFF0000
end