1.1.0 • Published 6 years ago
roya v1.1.0
Roya
Roya is a small low-level image comparison library.
Inspired by pixelmatch with more bells and whistles.
Installation
using yarn
yarn add roya
using npm
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 |
---|---|
options | result |
---|---|
undefined | |
{ threshold: 0.5 } | |
{ highlightColor: [255, 255, 0] } | |
{ highlightFade: false } | |
{ transparent: true, highlightFade: false } | |
{ overlapse: true, transparent: true } | |
{ method: 'rgb', highlightFade: false } | |
{ method: 'rgbTuned', highlightFade: false } | |
{ method: 'yiq', highlightFade: false } | |
{ method: 'yiqTuned', highlightFade: false } |
Usage
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.