This was written in Python2.7
Python3 Version
python encode.py --image <image file> --watermark <watermark file> --result <result file>
python decode.py --original <original image file> --image <image file> --result <result file>
Use --alpha to change the alpha (default 5.0).
original image
watermark
python encode.py --image ori.png --watermark watermark.png --result res.png
result
python decode.py --original ori.png --image res.png --result extract.png
watermark