RosettaCodeData/Task/Bitmap-Read-an-image-through-a-pipe/Lua/bitmap-read-an-image-through-a-pipe-2.lua

local bitmap = Bitmap(0,0)
fp = io.popen("magick Lenna100.jpg ppm:-", "rb")
bitmap:loadPPM(nil, fp)

bitmap:savePPM("Lenna100.ppm") -- just as "proof"