A library for encoding arbitrary data into images, a tecnique also known as steganography.

This is the foundation for the seagul cli application.

Basic example

Encode

Read an image and resave it with some verses encoded into it, using the last 2 bits on the blue channel of each pixel to encode them

let encode_result = super::ImageEncoder::from("source.png")
    .set_use_n_lsb(2)
    .set_use_channel(RgbChannel::Blue)
    .encode_data(
        b"
        Midway upon the journey of our life
        I found myself within a forest dark,
        For the straightforward pathway had been lost.
        Ah me! how hard a thing it is to say
        What was this forest savage, rough, and stern,
        Which in the very thought renews the fear.
        So bitter is it, death is little more;
        But of the good to treat, which there I found,
        Speak will I of the other things I saw there.
        I cannot well repeat how there I entered,
        So full was I of slumber at the moment
        In which I had abandoned the true way.",
    );

assert!(encode_result.is_ok(), "Encoding failed");

encode_result
    .unwrap()
    .save("encoded.png", ImageFormat::Png)
    .expect("Could not create output file");

Decode

let decoded = ImageDecoder::from("encoded.png")
    .set_use_n_lsb(2)
    .set_use_channel(RgbChannel::Blue)
    .until_marker(Some(b"way.")) // <- If you know how the message ends
    .decode();

assert!(decoded.is_ok());

let decoded = decoded.unwrap().as_raw();

println!("Raw decoded:\n{}", decoded_string);

Supported formats

While almost every major image format is supported as input, at the moment only PNG and BMP are supported as output formats. JPEG and other formats support is planned.