title: Modify the array RGBA Javascript
body: <p>Here is my JS function :   </p>
  
  <pre><code>UTIF._imgLoaded = function(e) {
      var page = UTIF.decode(e.target.response)[0], rgba = UTIF.toRGBA8(page), w=page.width, h=page.height;
  
      var string = rgba.join();
      console.log("rgba : ", rgba);
  
      var ind = UTIF._xhrs.indexOf(e.target), img = UTIF._imgs[ind];
      UTIF._xhrs.splice(ind,1);  UTIF._imgs.splice(ind,1);
      var cnv = document.createElement("canvas");  cnv.width=w;  cnv.height=h;
      var ctx = cnv.getContext("2d"), imgd = ctx.createImageData(w,h);
      for(var i=0; i&lt;rgba.length; i++) 
          imgd.data[i]=rgba[i];
      ctx.putImageData(imgd,0,0);
      var attr = ["style","class","id"];
      for(var i=0; i&lt;attr.length; i++) 
          cnv.setAttribute(attr[i], img.getAttribute(attr[i]));
      img.parentNode.replaceChild(cnv,img);
  
      var c = new Color(r, g, b, a);
      console.log(c);
      function changeColor(x, y, c) {
          rgba[(x * 4) + (y * (w * 4))] = c.r;
          rgba[(x * 4) + (y * (w * 4)) + 1] = c.g;
          rgba[(x * 4) + (y * (w * 4)) + 2] = c.b;
          rgba[(x * 4) + (y * (w * 4)) + 3] = c.a;
  
          console.log("Change :");
      }
  
      changeColor();
  
      document.getElementById("myText").innerHTML = string;
  }
  </code></pre>
  
  <p>I get a Uint8Array() RGBA of image, here is console.log of this : 
  <a href="https://i.stack.imgur.com/Ee9v0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Ee9v0.png" alt="enter image description here"></a></p>
  
  <p>Here is image with rgba array as a string in HTML:<a href="https://i.stack.imgur.com/flsln.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/flsln.png" alt="enter image description here"></a></p>
  
  <p>I try to change rgba of image by <code>changeColor()</code> function. I get in console.log error = "Color is not defined ". Thanks for help!</p>