From Wikipedia, steganography is the practice of concealing a file, message, image, or video within another file, message, image, or video. This simple tool allows embedding a text message into a .PGM Image file, using reversed bit encoding.
To compile with gcc
user@domain:~# gcc image.c main.c -o csteganograph
To encode a text message, use syntax:
user@domain:~# ./csteganograph encode <text-message-to-encode> <input-image-filename.pgm> <output-image-filename.pgm>
For example, to encode "This is the secret message (not really)" into file balloons.pgm, use:
user@domain:~# ./csteganograph encode "This is the secret message (not really)" balloons.pgm balloons-encoded.pgm
To decode an image and show the hidden message, use:
user@domain:~# ./csteganograph decode <encoded-image-filename.pgm>