Encrypting your message in images - steganography

https://github.com/alanthie/steganography

Windows:
stegano.exe encode -i img.png -e msg.txt -o out_image.png
stegano.exe decode -i out_image.png -o image_decoded.txt

Linux:
./steno decode -i out_image.png -o img_decoded.txt
./steno decode -i out_image.png -o image_decoded.txt