Use Cropper

Simple, mobile-friendly, animatable, customizable perspective cropper

Mobile-friendly dragging	Programmatic animating

• Live Demo

Usage

UI

import { useCropper } from 'use-cropper'

const { ref, coords } = useCropper('/path/to/image.png')
// or, for slightly better performance:
const { ref, getCoords } = useCropper('/path/to/image.png', {lazyCoords: true})

return (
  <div>
    <canvas style={{height: '100%', width: '100%' }} ref={ref} />
  </div>
)

Correcting

• worker.ts:

  import cv from "opencv-ts"; // or importScripts to a custom opencv.js, or whatever
  import { onMessage } from 'opencv-tools/workers/correct'
  onmessage = onMessage(cv)

• MyCropper.tsx

    import { prepareWorker } from 'opencv-tools/workers/correct'
  
    const worker = new Worker('/path/to/worker.ts')
    const api = prepareWorker(worker)
  
    const img = '/image.jpg'
  
    function MyCropper() {
  
      const { ref, getCoords } = useCropper(img, {lazyCoords: true})
  
        function initialize() {
          api.postImg(img) // not necessary, but makes subsequent calls faster
        }
  
        async function correct() {
          const blob = await api.correct(img, getCoords())
          ...
        }
      }

Animating

import { fabric } from 'fabric' // optionally, for predefined easing functions

const { ref, animate } = useCropper('/path/to/image.png')

async function runAnimation() {
  if (!animate.loaded)
    return
  await animate({ tl: [0.1, 0.1], tr: [0.9, 0.1] }, { easing: fabric.util.ease.easeOutExpo })
  await new Promise(r => setTimeout(r, 200))
  await animate({ tl: [0, 0], tr: [1, 0] })
}

Hint/Animation

Optionally, you can install framer-animations to add this animation (useful as a simple guide for users)

npm i framer-animations

yarn add framer-animations

import { useCropper } from 'use-cropper'
import { useCropperAnimation } from 'use-cropper/animation'

const { ref, animate } = useCropper('/image.jpg')
const { animation, run } = useCropperAnimation(animate)

return (
  ...
  <div style={{position: 'relative'}}>
    <canvas style={{height: '100%', width: '100%' }} ref={ref} />
    {animation}
  </div>
  <button onClick={run}>Help</button>
  ...
)