get("#348") -- rgb functions

function stringRepImage(img)
  local x, y, w, h = 0, 0, img.width, img.height -- full image

  local tbl = {}
  for yy=y, y+h-1 do
    if yy > y then table.insert(tbl, ".") end
    for xx=x, x+w-1 do
      local pix = img.getInt(xx, yy)
      local b = math.floor(bright(rgb(pix))*25+0.5)
      table.insert(tbl, string.char(string.byte("A")+b))
    end
  end
  return table.concat(tbl)
end

Began life as a copy of #382