To crop an image using HTML5 Canvas, we can add six additional arguments to the drawImage() method, sourceX, sourceY,sourceWidth, sourceHeight, destWidth and destHeight. These arguments define the location and size of a rectangle that we want to cut out of an image.
Reference: www.whatwg.org
Code Editor
var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
var imageObj = new Image();
imageObj.onload = function() {
// draw cropped image
var sourceX = 150;
var sourceY = 0;
var sourceWidth = 150;
var sourceHeight = 150;
var destWidth = sourceWidth;
var destHeight = sourceHeight;
var destX = canvas.width / 2 - destWidth / 2;
var destY = canvas.height / 2 - destHeight / 2;
context.drawImage(imageObj, sourceX, sourceY, sourceWidth, sourceHeight, destX, destY, destWidth, destHeight);
};
imageObj.src = 'http://www.html5canvastutorials.com/demos/assets/darth-vader.jpg';
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