jquery实现颜色拾取功能

(function ($) {
 $.fn.pickerColor=function (option) {
  var opt ={
  ck:function () {}
  },_this=this
  opt=$.extend(opt,option);
  _this.on('click',function (e) {
  var canvasObj = '';
  $('body').append(canvasObj);
  var cvs = document.getElementById("canvasPickerColor"),ctx =cvs.getContext('2d')
  cvs.height=1;cvs.width=1
  var img = new Image();
  img.src=_this.attr('src');
  var osX=e.offsetX,osY=e.offsetY
  ctx.drawImage(img,osX,osY,1,1,0,0,1,1);
  var imgData=ctx.getImageData(0,0,1,1);
  console.log(imgData)
  if(opt.ck) opt.ck(imgData.data[0]+','+imgData.data[1]+','+imgData.data[2]);
  })
 }
 })(jQuery)

$(function () {
 $('.source').pickerColor({
  ck:function (data) {
  console.log(data)
  $('.color').css('background','rgba('+data+',1)')
  }
 })
 })