This program use the least significant bits of the Red and Green channel of a png file to hide or read a message.
To write a message in a picture :
./main.py -f images/rgb.png -t "this is a very secret message I don't want anybody to see"
To read a message from a picture :
./main.py --filename hidden.png --mode read
the hidden message will be saved in hidden.txt
This program works with all kind of png files (greyscale, greyscale+alpha, rgb, rgba, palette or not).