jscanify/README.md
2023-05-08 17:51:13 -04:00

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<p align="center">
<img src="docs/images/logo-full.png" height="100">
</p>
<p align="center">
<a href="https://github.com/ColonelParrot/jscanify/blob/master/LICENSE"><img src="https://img.shields.io/github/license/ColonelParrot/jscanify.svg"></a>
<a href="https://GitHub.com/ColonelParrot/jscanify/releases/"><img src="https://img.shields.io/github/release/ColonelParrot/jscanify.svg"></a>
<a href="https://npmjs.com/package/jscanify"><img src="https://badgen.net/npm/v/jscanify"></a>
</p>
<p align="center">
<a href="https://nodei.co/npm/jscanify/"><img src="https://nodei.co/npm/jscanify.png"></a>
</p>
<p align="center">
Open-source pure Javascript implemented mobile document scanner. Powered with <a href="https://docs.opencv.org/3.4/d5/d10/tutorial_js_root.html">opencv.js</a><br/><br/>
Available on <a href="https://www.npmjs.com/package/jscanify">npm</a> or via <a href="https://www.jsdelivr.com/package/gh/ColonelParrot/jscanify">cdn</a>
</p>
**Features**:
- paper detection & highlighting
- paper scanning with distortion correction
| Image Highlighting | Scanned Result |
| ------------------------------------------------- | ----------------------------------------------- |
| <img src="docs/images/highlight-paper1.png"> | <img src="docs/images/scanned-paper1.png"> |
| <img src="docs/images/highlight-paper2.png"> | <img src="docs/images/scanned-paper2.png"> |
## Quickstart
### Import
npm:
```js
$ npm i jscanify
import jscanify from 'jscanify'
```
cdn:
```html
<script src="https://docs.opencv.org/4.7.0/opencv.js" async></script>
<!-- warning: loading OpenCV can take some time. Load asynchronously -->
<script src="https://cdn.jsdelivr.net/gh/ColonelParrot/jscanify@master/src/jscanify.min.js"></script>
```
> **Note**: jscanify on NodeJS is slightly different. See [wiki: use on NodeJS](https://github.com/ColonelParrot/jscanify/wiki#use-on-nodejs).
### Highlight Paper in Image
```html
<img src="/path/to/your/image.png" id="image" />
```
```js
const scanner = new jscanify();
image.onload = function () {
const highlightedCanvas = scanner.highlightPaper(image);
document.body.appendChild(highlightedCanvas);
};
```
### Extract Paper
```js
const scanner = new jscanify();
const paperWidth = 500;
const paperHeight = 1000;
image.onload = function () {
scanner.extractPaper(image, paperWidth, paperHeight, (resultCanvas) => {
document.body.appendChild(resultCanvas);
});
};
```
### Highlighting Paper in User Camera
The following code continuously reads from the user's camera and highlights the paper:
```html
<video id="video"></video>
<canvas id="canvas"></canvas> <!-- original video -->
<canvas id="result"></canvas> <!-- highlighted video -->
```
```js
const scanner = new jscanify();
const canvasCtx = canvas.getContext("2d");
const resultCtx = result.getContext("2d");
navigator.mediaDevices.getUserMedia({ video: true }).then((stream) => {
video.srcObject = stream;
video.onloadedmetadata = () => {
video.play();
setInterval(() => {
canvasCtx.drawImage(video, 0, 0);
const resultCanvas = scanner.highlightPaper(canvas);
resultCtx.drawImage(resultCanvas, 0, 0);
}, 10);
};
});
```
To export the paper to a PDF, see [here](https://stackoverflow.com/questions/23681325/convert-canvas-to-pdf)
### Notes
- for optimal paper detection, the paper should be placed on a flat surface with a solid background color
- we recommend wrapping your code using `jscanify` in a window `load` event listener to ensure OpenCV is loaded