https://github.com/mouafa/roya

🔎 Find diff between two images
https://github.com/mouafa/roya

diff matching regression

Last synced: 4 months ago
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🔎 Find diff between two images

• Host: GitHub
• URL: https://github.com/mouafa/roya
• Owner: mouafa
• Created: 2018-08-31T20:19:48.000Z (over 6 years ago)
• Default Branch: master
• Last Pushed: 2019-02-21T13:58:39.000Z (almost 6 years ago)
• Last Synced: 2024-10-22T05:17:13.617Z (4 months ago)
• Topics: diff, matching, regression
• Language: JavaScript
• Homepage: https://www.npmjs.com/package/malal
• Size: 130 KB
• Stars: 1
• Watchers: 0
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        


Roya is a small low-level image comparison library.

[![npm version](https://badge.fury.io/js/roya.svg)](https://badge.fury.io/js/roya)

[![Coverage Status](https://coveralls.io/repos/github/mouafa/roya/badge.svg?branch=master)](https://coveralls.io/github/mouafa/roya?branch=master)

[![Build Status](https://api.travis-ci.org/mouafa/roya.svg?branch=master)](https://travis-ci.org/mouafa/roya#)

Inspired by [pixelmatch](https://github.com/mapbox/pixelmatch) with more bells and whistles.

## Installation

using yarn

```bash

yarn add roya

```

using npm

```bash

npm i -S roya

```

### API

```

roya(img1, img2, [, options])

```

`img1`, `img2` — Image data of type `Buffer` of the images to compare

`options` Optional object options with the following properties:

| Property       | Description                                                                                                    | Default     |

| -------------- | -------------------------------------------------------------------------------------------------------------- | ----------- |

| threshold      | Matching threshold, ranges from 0 to 1. Smaller values make the comparison more sensitive                      | 0.1         |

| highlightFade  | Highlight color intensity will depend on the pixel ditance value                                               | true        |

| highlightColor | The used highlight color, should be an array of [R,G,B] values                                                 | [255, 0, 0] |

| transparent    | Whether to keep the original image ot to use a blank convas to highlight the diff                              | false       |

| overlapse      | Whether to use the highlight color or use the changing pixel itself                                            | false       |

| method         | Matching and diffing method to be used, should be one of the available methods, rgb, rgbTuned, yiq or yiqTuned | 'rgb'       |

**P.S.** rgb method is the fastest but it might not be the best for your usecase, try the others method and pick the right one for you.

### Example:

| img1                            | img2                            |

| ------------------------------- | ------------------------------- |

| ![](testdrive/fixture/img1.png) | ![](testdrive/fixture/img2.png) |

| options                                        | result                                           |

| ---------------------------------------------- | ------------------------------------------------ |

| `undefined`                                    | ![](testdrive/fixture/diff_default.png)          |

| `{ threshold: 0.5 }`                           | ![](testdrive/fixture/diff_higher_threshold.png) |

| `{ highlightColor: [255, 255, 0] }`            | ![](testdrive/fixture/diff_yellow.png)           |

| `{ highlightFade: false }`                     | ![](testdrive/fixture/diff_solid.png)            |

| `{ transparent: true, highlightFade: false }`  | ![](testdrive/fixture/diff_transparent.png)      |

| `{ overlapse: true, transparent: true }`       | ![](testdrive/fixture/diff_overlapse.png)        |

|                                                |

| `{ method: 'rgb', highlightFade: false }`      | ![](testdrive/fixture/diff_method_rgb.png)       |

| `{ method: 'rgbTuned', highlightFade: false }` | ![](testdrive/fixture/diff_method_rgbTuned.png)  |

| `{ method: 'yiq', highlightFade: false }`      | ![](testdrive/fixture/diff_method_yiq.png)       |

| `{ method: 'yiqTuned', highlightFade: false }` | ![](testdrive/fixture/diff_method_yiqTuned.png)  |

## Usage

```js

const fs = require('fs')

const PNG = require('pngjs').PNG

const roya = require('roya')

var img1 = fs

  .createReadStream('img1.png')

  .pipe(new PNG())

  .on('parsed', parsed)

var img2 = fs

  .createReadStream('img2.png')

  .pipe(new PNG())

  .on('parsed', parsed)

let done = 0

function parsed() {

  done++

  if (done < 2) return

  const out = roya(img1.data, img2.data)

  const diff = new PNG({ width: img1.width, height: img1.height })

  diff.data = out.data

  diff

    .pack()

    .pipe(fs.createWriteStream('diff.png'))

    .on('finish', () => console.log('done'))

}

```

**P.S.** image dimensions must be equal.