Flutter Steganograph

---

Flutter Steganograph is a digital image encoding package that embeds a message (text or image) into a cover image/text using the least significant bit (LSB) technique with minimal alteration to the original cover image/text.

Installation 🛸

Add flutter_steganograph to your pubspec.yaml:

dependencies:
  flutter_steganograph: ^0.1.0

Usage 📦

Importing the Package

import 'package:flutter_steganograph/flutter_steganograph.dart';

Embed a secret text into a cover text ♟️

Embeds a secret text inside a cover text using zero-width characters. Returns a string with the secret message embedded inside cover text, invisible to normal readers.

import 'package:flutter_steganograph/src/flutter_steganograph.dart';

final steganograph = Steganograph();

String embeddedText = steganograph.embedTextInText(
    coverText: 'cover text sample', 
    secretMessage: 'super secret text to hide',
    );
print(embeddedText);

Extract the secret text from cover text ♖

Extracts a text message embedded in a text using zero-width characters. Returns the extracted secret message. If no secret message is found, returns a message indicating this.

import 'package:flutter_steganograph/src/flutter_steganograph.dart';

final steganograph = Steganograph();

String secretText = steganograph.extractTextFromText(
    encodedText: 'cover text sample',
    );
print(secretText);

Embed a text into an image 🔩

Embeds a text string into an image. Optional saveImage argument to download embedded image to gallery. Returns the encoded bytes -> Uint8List.

import 'package:image/image.dart' as dImage;
import 'package:flutter_steganograph/src/flutter_steganograph.dart';

final steganograph = Steganograph();
final coverImage = dImage.decodePng(File('/cover_image.png').readAsBytesSync())!;

final embeddedTextImage = steganograph.embedText(
    image: coverImage, 
    text: 'super secret text',
    saveImage: true
    );
// to covert to material image
Image.memory(embeddedTextImage);

Extract the secret text from the encoded image 🔬

Extracts a secret text string from an encoded image. Returns the extracted secret String

import 'package:image/image.dart' as dImage;
import 'package:flutter_steganograph/src/flutter_steganograph.dart';

final steganograph = Steganograph();
final encodedImage = dImage.decodePng(File('/encoded_image.png').readAsBytesSync())!;
int secretLength = secretText.length;

String secretText = steganograph.extractText(
    image: encodedImage, 
    length: secretLength,
    );

Embed a secret Image inside a cover image 🖼️

Embed/encode a secret image inside a cover image. secret image dimensions are smaller than cover image dimensions. Returns the embedded bytes -> Uint8List of encoded image.

import 'package:image/image.dart' as dImage;
import 'package:flutter_steganograph/src/flutter_steganograph.dart';

final steganograph = Steganograph();
final coverImage = dImage.decodePng(File('/cover_image.png').readAsBytesSync())!;
final secretImage = dImage.decodePng(File('/secret_image.png').readAsBytesSync())!;

Uint8List embeddedImage = steganograph.embedImage(
        coverImage: coverImage,
        secretImage: secretImage,
      );
//to covert to material image
Image.memory(embeddedImage);

Extract the secret Image from an encoded image 🧮

decode a secret image from the encoded image. Returns the embedded bytes -> Uint8List of secret image.

import 'package:image/image.dart' as dImage;
import 'package:flutter_steganograph/src/flutter_steganograph.dart';

final steganograph = Steganograph();
final encodedImage = dImage.decodePng(File('/encodedImage_image.png').readAsBytesSync())!;
int secretImageHeight;
int secretImageWith;

Uint8List extractedImage = steganograph.extractImage(
        embeddedImage: encodedImage!,
        secretWidth: secretImageHeight,
        secretHeight: secretImageHeight,
      );
//to covert to material image
Image.memory(extractedImage);

Coming soon

encryption 🔒 of secret text and image

Contribution

Feel free to open pull requests that improve the quality of images or performance of the library. Any bugs should be submitted to Issues