please Use Jupyter Notebook
filetype is .ipynb

this can encoring text to image. at ./image_incording/image_encording.ipynb, edit before_image_path and save_image_path. and type text what you want to lay over at image. then, encorded image will saved.

for decording, open ./image_incording/image_decording.ipynb you can decording.

when you encording, the text is changed to ascii code and ascii code will change the pixel's blue value. when decording, it works inverse.