JSFiddle - React, Tailwind, and code Playground
by AlexJsh02
HTML
<script src="https://code.jquery.com/jquery-1.12.0.min.js"></script>
<div style="display:none;">
<img id="logo_source"...
JavaScript
// canvas
var logo = document.getElementById("logo");
var ctx = logo.getContext("2d");
var img = new Image();
img.src = $("#logo_source").attr("src");
img.onload = function(){
//logo.width = img.width;
//logo.height = img.height;
ctx.drawImage(img, 0, 0);
// create hidden canvas (using image dimensions)
//var canvas = document.createElement("canvas");
//canvas.width = logo.offsetWidth;
//canvas.height = logo.offsetHeight;
//var context = canvas.getContext("2d");
//ctx.drawImage(imgElement,0,0);
//var map = ctx.getImageData(0,0,img.width,img.height);
//var imdata = map.data;
// convert image to grayscale
//var r,g,b,avg;
//for(var p = 0, len = imdata.length; p < len; p+=4) {
//r = imdata[p]
//g = imdata[p+1];
//b = imdata[p+2];
// alpha channel (p+3) is ignored
//avg = Math.floor((r+g+b)/3);
//imdata[p] = imdata[p+1] = imdata[p+2] = avg;
//}
//context.putImageData(map,0,0);
// overlay filled rectangle using lighter composition
//context.globalCompositeOperation = "lighter";
//context.globalAlpha = 0.5;
//context.fillStyle="red";
//context.fillRect(0,0,canvas.width,canvas.height);
};