How to compress image size in JavaScript?

Question

I am trying to compress image size using JavaScript. but it returns canvas error. below is my code.

 var reader = new FileReader();
        reader.readAsDat         


        

Answer 1

You might have to resize the canvas size

refer the following example here

function resizeImg(base, width, height) {
    var canvas = document.createElement("canvas");
    canvas.width = width;
    canvas.height = height;
    var context = canvas.getContext("2d");
    var deferred = $.Deferred();
    $("").attr("src", "data:image/gif;base," + base).load(function() {
        context.scale(width/this.width,  height/this.height);
        context.drawImage(this, 0, 0); 
        deferred.resolve($("").attr("src", canvas.toDataURL()));               
    });
    return deferred.promise();    
}