在javascript或jQuery中将img src转换为输入文件

Question

How do I convert from a img src to a input of type file?

I'm using webcamjs and it gives me a data_uri for an image src that looks like this

 Webcam.snap(function(data_uri) { document.getElementById('my_result_front').innerHTML = '<img id="webcamImageToCropFront" src="' + data_uri + '"/>'; }); 

and now I need to convert the image source into a file that I can pass to my form like this

 const data = new FormData(); data.append('file', document.querySelector('#id-file').files[0]); 

where #id-file is a input of type file like this

 <input type="file" id="id-file" name="id-file" accept=".jpeg,.jpg,.png"> 

Answer 1

Try using a base 64 convert like this post: CONVERT Image url to Base64

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);
  var dataURL = canvas.toDataURL("image/png");
  return dataURL.replace(/^data:image\/(png|jpg);base64,/, "");
}

var base64 = getBase64Image(document.getElementById("webcamImageToCropFront"));

Then pass your base64 string to the form as it contains all of the image data!

Hope that helps.