liu521-v2/watermark_demo

DCT and LSB watermark algorithm

Digital image encryption ---- invisible watermark

Introduction

Invisible watermark contains two algorithms: significant Bit(LSB) and Discrete Cosine Transform(DCT) refer guofei9987 , importantly , the DCT algorithm needs the carrier image size should 16 times greater than watermark, or it doesn't work.

Requirements

These scripts need python 3.6+ and the following libraries:

numpy==1.19.5
opencv-python==4.5.1.48
PyWavelets==1.1.1

You can easy to install these libraries by :

pip install -r requirements.txt

Running

First of all, you need satisfy the environment requirements, then run

python main.py --ori_filename <carrier image path> --wm_filename <watermark path>

you can get a image include watermark, the default path under***./img/***.

Encode

Above-mentioned is the most convenient way encode, but formally, you need to run this

python main.py --ori_filename <carrier image path> --wm_filename <watermark path> --coder encoder

For example

python main.py --ori_filename ./img/carrier.png  --wm_filename ./img/watermark.png --coder encoder

In addition, you can use -wm_method to choose DCT algorithm (default) or LSB algorithm to encode the watermark, you can just run like this

python main.py --ori_filename ./img/carrier.png  --wm_filename ./img/watermark.png --coder encoder --wm_method LSB

Furthermore,it also support the usual attack method to destroy image,you need to run this

python main.py --ori_filename ./img/carrier.png  --wm_filename ./img/watermark.png --coder encoder --att_method saltnoise

The all attack methods you can look up in ./src/attack.py, and the watermarked image will be saved under the path *./img/.

Decode

Above all, you need to confirm the watermarked image is encoded by which algorithm, then you can run like this

python main.py --wm_filename ./img/watermark.png --ori_wm_filename ./img/ori_wm.png --coder decoder 

As you see, the all algorithms needs the watermark image to decode, because the watermark size we don't know.