<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="x-ua-compatible" content="ie=edge">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<title>Cropper.js</title>
<link rel="stylesheet" href="../css/cropper.css">
<style>
.container {
margin: 20px auto;
max-width: 640px;
}
img {
max-width: 100%;
}
.cropper-view-box,
.cropper-face {
background-color: black;
opacity: 1;
}
</style>
</head>
<body>
<div class="container">
<h1>Mask an image (Redaction)</h1>
<h3>Image</h3>
<div>
<img id="image" src="../images/picture.jpg" alt="Picture">
</div>
<h3>Result</h3>
<p><button type="button" id="button">Mask</button></p>
<div id="result"></div>
</div>
<script src="../js/cropper.js"></script>
<script>
function getMaskedCanvas(sourceCanvas, sourceImage, cropper) {
var canvas = document.createElement('canvas');
var context = canvas.getContext('2d');
var maskWidth = cropper.getData().width;
var maskHeight = cropper.getData().height;
var maskTop = cropper.getData().y;
var maskLeft = cropper.getData().x;
var imageWidth = cropper.getImageData().naturalWidth;
var imageHeight = cropper.getImageData().naturalHeight;
var imageLeft = cropper.getImageData().left;
var imageTop = cropper.getImageData().top;
var imageAspect = cropper.getImageData().aspectRatio;
canvas.width = imageWidth;
canvas.height = imageHeight;
// Debug
console.log('Image Width: ' + imageWidth + ' Image Height: ' + imageHeight + ' Image Aspect Ratio: ' + imageAspect );
console.log('Image Left: ' + imageLeft + ' Image Top: ' + imageTop );
console.log('Mask Width: ' + maskWidth + ' Mask Height: ' + maskHeight + ' Mask Left: ' + maskLeft + ' Mask Top: ' + maskTop);
context.imageSmoothingEnabled = true;
context.drawImage(image, 0, 0, imageWidth, imageHeight);
context.fillRect(maskLeft, maskTop, maskWidth, maskHeight);
return canvas;
}
window.addEventListener('DOMContentLoaded', function () {
var image = document.getElementById('image');
var button = document.getElementById('button');
var result = document.getElementById('result');
var croppable = false;
var cropper = new Cropper(image, {
viewMode: 0,
guides: true,
center: true,
highlight: true,
cropBoxMovable: true,
cropBoxResizable: true,
ready: function () {
croppable = true;
},
});
button.onclick = function () {
var croppedCanvas;
var maskedCanvas;
var maskedImage;
if (!croppable) {
return;
}
// Crop
croppedCanvas = cropper.getCroppedCanvas();
// Mask
maskedCanvas = getMaskedCanvas(croppedCanvas, image, cropper);
// Show
maskedImage = document.createElement('img');
maskedImage.src = maskedCanvas.toDataURL();
result.innerHTML = '';
result.appendChild(maskedImage);
};
});
</script>
</body>
</html>
