如何将dataurl转换回图像并显示在画布上

我有3幅油画。我从canvas1裁剪一个区域并将其显示在画布2上。然后我想将Canvas2图像转换为一个URL,看看是否可以将该URL转换回一个图像。我想把它展示在画布C4上。谢谢你的帮助。

// image is drawn here , I want this image to be converted to a dataURL 
//then back to image and display it in canvas c4
var c2 =  document.getElementById("area_c2");

 var ctx = c.getContext("2d");
 var ctx2 = c2.getContext("2d");
 image_src.width = c2.width;
 image_src.height = c2.height;

ctx2.drawImage(image_src, 0, 0,image_src.width, image_src.height);




 var c4 =  document.getElementById("area_c4");
 var ctx4 = c4.getContext("2d");

 var dataURL = c2.toDataURL();

 var myImg = new Image;

 myImg.src = dataURL;

 myImg.width = c4.width;
 myImg.height = c4.height;

 ctx4.drawImage(myImg, 0, 0, image_src.width, image_src.height); //Image //is not displayed here , I want the image to take the size of the canvas


  <canvas  id ="area_c2" style="width:300px;height:300px;border:3px solid 
  black;z-index:1"  >
  </canvas>


 <canvas id ="area_c4" style="width:300px;height:300px;border:3px solid 
   black;z-index:1;background:red">
 </canvas>