def METHOD_NAME(meta, mean, std):
    img = meta['img'].astype(np.float32) / 255
    mean = np.array(mean, dtype=np.float32).reshape(1, 1, 3) / 255
    std = np.array(std, dtype=np.float32).reshape(1, 1, 3) / 255
    img = (img - mean) / std
    meta['img'] = img
    return meta