@antv/vis-steg

✨ Features

- Information Encoding and Decoding: A javascript library for embedding information within visualization images.
The decoding algorithm just relys on the encoded image.
- String and Bits Array Transformation: Converting a string to a bits array and vice versa using UTF8 encoding and decoding.

- QR Code for Error Correction: Add QR code as error correction code before encoding and after decoding.

📦 Installation

``bash
$ npm install
`

🔨 Getting Started

Basic use

- Information Encoding

`ts
import { LSBSteg } from './src';

const testLSBSteg = new LSBSteg();
const secretInfo = 'hello';
testLSBSteg.writeLSB({
imgBitmapData: imgBitmapData,
imgHeight: img.height,
imgWidth: img.width,
secretInfo,
});
`

- Information Decoding

`ts
import { LSBSteg } from './src';

const testLSBSteg = new LSBSteg();
const decodeSecret = testLSBSteg.readLSB({
imgBitmapData: imgBitmapData,
imgHeight: img.height,
imgWidth: img.width,
});
`

with QR Code ECC

- Information Encoding

`ts
import { LSBSteg } from './src';

const testLSBSteg = new LSBSteg();
const secretInfo = 'hello';
testLSBSteg.writeLSB({
imgBitmapData: imgBitmapData,
imgHeight: img.height,
imgWidth: img.width,
secretInfo,
encMode: 'QRcode',
QRSize: 200,
mxMsgLen: 130
});
`

- Information Decoding

`ts
import { LSBSteg } from './src';

const testLSBSteg = new LSBSteg();
const decodeSecret = testLSBSteg.readLSB({
imgBitmapData: imgBitmapData,
imgHeight: img.height,
imgWidth: img.width,
decMode: 'QRcode'
});
`

:cookie: Demo

> ### LSB Encode Process
>
> - ### Input
>
> `
> - RGB (or gray) Image
> - Secret String
> - Encode Mode
> - Options
> `
>
> - ### Process
>
> 1. Adjust RGB (or gray) image to RGBA form.
> 2. Add a head string for further check.
> 3. Convert the head string, secret string length and secret string to bits array, and merge them together.
> 4. Embed the bits array into the container image. The replacing is from the least bit to the highest bit.

> ### LSB Decode Process
>
> - ### Input
>
> `
> - RGBA Image
> - Decode Mode
> ``
>
> - ### Process
>
> 1. Read the head string for decoding check.
> 2. Read the secret string length (64 bits).
> 3. Read the secret string bits array and convert it to string.

License

MIT