Perubahan warna imej yang dilukis pada elemen kanvas HTML5

function display(img1, red, gr, bl) { //func to change color of image    
var canvas1 = document.createElement('canvas');//canvas element initialisation

canvas1.width = img.width;//canvas width initialisation    
canvas1.height = img.height; //canvas height initialisation

var ctx1 = canvas1.getContext('2d');    
ctx1.drawImage(img, 0, 0);

var myImg =ctx1.getImageData(0, 0, canvas1.width, canvas1.height);
for (var t=0;t< myImg.data.length;t+=4) {        
   myImg.data[t]= red | myImg.data[t];        
   myImg.data[t+1]= gr | myImg.data[t+1];        
   myImg.data[t+2]= bl | myImg.data[t+2];    
}
ctx1.putImageData(myImg,0,0); // Image data is adjusted according to context    
return c;
},