utils.py

def to_bin(data):
    """Convert `data` to binary format as string"""
    if isinstance(data, str):
        return ''.join([ format(ord(i), "08b") for i in data ])
    elif isinstance(data, bytes):
        return ''.join([ format(i, "08b") for i in data ])
    elif isinstance(data, np.ndarray):
        return [ format(i, "08b") for i in data ]
    elif isinstance(data, int) or isinstance(data, np.uint8):
        return format(data, "08b")
    else:
        raise TypeError("Type not supported.")
def decode(image_name,txt=None):
    msg=""
    BGRimage = cv2.imread(image_name)
    image = cv2.cvtColor(BGRimage, cv2.COLOR_BGR2RGB)   
    binary_data = ""
    for row in image:
        for pixel in row:
            r, g, b = to_bin(pixel)
            binary_data += r[-1]
            binary_data += g[-1]
            binary_data += b[-1]
    all_bytes = [ binary_data[i: i+8] for i in range(0, len(binary_data), 8) ]
    decoded_data = ""
    for byte in all_bytes:
        decoded_data += chr(int(byte, 2))
        if decoded_data[-5:] == "=====":
            break
    this = decoded_data[:-5].split("#####",1)[0]
    this = eval(this)
    enc_in=this
    return this,msg

def encode(image_name, secret_data,txt=None):
    msg=""
    BGRimage = cv2.imread(image_name)
    image = cv2.cvtColor(BGRimage, cv2.COLOR_BGR2RGB)    
    n_bytes = image.shape[0] * image.shape[1] * 3 // 8
    print("[*] Maximum bytes to encode:", n_bytes)
    secret_data1=secret_data
    while True:
        if len(secret_data1)+5 < (n_bytes):
            secret_data1 = f'{secret_data1}#####'
        elif len(secret_data1)+5 >= (n_bytes):
            break    
    secret_data = secret_data1    
    if len(secret_data) > n_bytes:
        msg ="Watermark is too large for Image Size"
        return image_name,msg
    secret_data += "====="
    data_index = 0
    binary_secret_data = to_bin(secret_data)
    data_len = len(binary_secret_data)
    for row in image:
        for pixel in row:
            r, g, b = to_bin(pixel)
            if data_index < data_len:
                pixel[0] = int(r[:-1] + binary_secret_data[data_index], 2)
                data_index += 1
            if data_index < data_len:
                pixel[1] = int(g[:-1] + binary_secret_data[data_index], 2)
                data_index += 1
            if data_index < data_len:
                pixel[2] = int(b[:-1] + binary_secret_data[data_index], 2)
                data_index += 1
            if data_index >= data_len:
                break
    return image,msg