js如何将base64和图片之间进行转换

js如何将图片转换成base64格式，下面web建站小编给大家详细介绍一下是转换代码！

将图片转换成base64格式

var img = "https://ipkd.cn/images/logo.png";
  
function getBase64Image(img) { 
  var canvas = document.createElement("canvas"); 
  canvas.width = img.width; 
  canvas.height = img.height; 
  var ctx = canvas.getContext("2d"); 
  ctx.drawImage(img, 0, 0, img.width, img.height); 
  var ext = img.src.substring(img.src.lastIndexOf(".")+1).toLowerCase(); 
  var dataURL = canvas.toDataURL("image/"+ext); 
  return dataURL; 
} 
  
var image = new Image(); 
image.src = img; 
image.onload = function(){ 
  var base64 = getBase64Image(image); 
  console.log(base64); 
}