周期噪音攻击 - Githubissues

将最低三位用周期噪音代替后水印就失效了，大致代码如下：

from blind_watermark import WaterMark
import numpy as np
import imageio.v2 as imageio
import random

seed = 13
random.seed( seed )
np.random.seed( 13 )

orig_image_path = './wm1.jpg'
orig_embed_image_path = './wm1.embed.jpg'
attack_embed_image_path = './wm1.embed_attack.jpg'

bwm1 = WaterMark(password_img=1, password_wm=1)
bwm1.read_img( orig_image_path )
wm = '@guofei9987 开源万岁！'
bwm1.read_wm(wm, mode='str')
bwm1.embed( orig_embed_image_path )
len_wm = len(bwm1.wm_bit)
print('Put down the length of wm_bit {len_wm}'.format(len_wm=len_wm))

def extract_watermark( image_path ):
    bwm1 = WaterMark(password_img=1, password_wm=1)
    wm_extract = bwm1.extract(image_path, wm_shape=len_wm, mode='str')
    return wm_extract

def periodic_noise( shape ):
    ans = np.zeros( shape, dtype='float64' )
    ans = ans.reshape( ( ans.size, ) )

    loops = 10
    for idx in range( loops ):
        dat = np.arange( ans.size, dtype='float64' )
        dat = 0.025 * (idx+1+random.random()*0.0345) * dat * dat + random.random()*6.28
        ans += np.sin( dat )

    ans = np.abs( ans.reshape( shape ) )
    ans /= np.amax( ans )
    return ans

def lsb_attack( image_path, bit = 3, output_path = None ):
    image = 1.0 * np.asarray( imageio.imread( image_path ) )
    max_peak = 2**bit

    image /= max_peak
    image = 1.0 * np.asarray( image, dtype='uint8' ) + periodic_noise( image.shape )
    #image = 1.0 * np.asarray( image, dtype='uint8' )
    image *= max_peak
    image = np.asarray( image, dtype='uint8' )

    if output_path is not None:
        imageio.imwrite( output_path, image )

    return image

lsb_attack( orig_embed_image_path, 3,  attack_embed_image_path )

print( 'before attack: ', extract_watermark('./wm1.embed.jpg') )
print( 'after attack: ', extract_watermark(attack_embed_image_path) )

输出为：


Welcome to use blind-watermark, version = 0.4.1
Make sure the version is the same when encode and decode
Your star means a lot: https://github.com/guofei9987/blind_watermark
This message only show once. To close it: `blind_watermark.bw_notes.close()`

Put down the length of wm_bit 215
before attack:  @guofei9987 开源万岁！
after attack:  @gTOne�8902 开�P�(�岁o��

测试图片选择分辨率为 2048x2048 以尽量方便水印隐藏： https://github.com/fengwang/blind_watermark/blob/master/examples/pic/wm1.jpg

guofei9987 / blind_watermark

周期噪音攻击 #88