Pngblob is software for graphics encryption.
Pngblob can turn any file to png image using any png image as key its purpose is to protect any file. Here is sources codes for this application, to create this i use Qtcreator as IDE and QT libraries as frontend. If you prefer pngblob can generate unique random graphics encryption key for you. If you do not want generated key then you can use some image as a key.
->png: this button select file to encrypt
png-->: this button select encrypted secret file for decryption
key: this button generates png image to use as personal encryption key, file name is key.png this generated image key can be exchanged with your friends, then they can read your files. Without key nobody can open encrypted files.
exit: exit app.