def decode_to_file(image_name, num_bits, filename):
    image = sim.read_image(image_name)
    message = decode_ext(image, num_bits)
    file = open(filename,'w')
    file.write(message)
    file.close
    return message 
def decode_direct(image_name, num_bits):
    image = sim.read_image(image_name)
    message = decode_ext(image,num_bits)
    return message
def encode_direct(image_name,message,num_bits,coded_image_name):
    image = sim.read_image(image_name)
    encoded_image = encode_ext(image,message,num_bits)
    sim.write_image(encoded_image, coded_image_name)
    return None