Using steganography for SHAREWARE
There are two main files here, encode.sh and recover.sh They use Image Magick to interpret raw bytes of data into a png and back.
The only 'gotcha' is the file needs to padded to the byte size of the pixel resolution you want. I use truncate for that in encode.sh.
DOOM logo copyright iD software.
Steganography code from this Image Magick thread. https://legacy.imagemagick.org/discourse-server/viewtopic.php?t=30958