How to Capture or Export HTML5 Canvas to GIF/JPG/PNG Images and PDF Documents in Browser Using Javascript Full Project For Beginners

 

var canvas = document.getElementById("mycanvas");
var img    = canvas.toDataURL("image/png");

with the value in IMG you can write it out as a new Image like so:

document.write('<img src="'+img+'"/>');

 

 

HTML5 provides Canvas.toDataURL(mimetype) which is implemented in Opera, Firefox, and Safari 4 beta. There are a number of security restrictions, however (mostly to do with drawing content from another origin onto the canvas).

So you don’t need an additional library.

e.g.

 <canvas id=canvas width=200 height=200></canvas>
 <script>
      window.onload = function() {
          var canvas = document.getElementById("canvas");
          var context = canvas.getContext("2d");
          context.fillStyle = "green";
          context.fillRect(50, 50, 100, 100);
          // no argument defaults to image/png; image/jpeg, etc also work on some
          // implementations -- image/png is the only one that must be supported per spec.
          window.location = canvas.toDataURL("image/png");
      }
 </script>

Theoretically this should create and then navigate to an image with a green square in the middle of it, but I haven’t tested.

 

 

In order to get the canvas as an image, you should do the following:

var canvas = document.getElementById("mycanvas");
var image = canvas.toDataURL("image/png");

You can use this to write the image to the page:

document.write('<img src="'+image+'"/>');

Where “image/png” is a mime type (png is the only one that must be supported). If you would like an array of the supported types you can do something along the lines of this:

var imageMimes = ['image/png', 'image/bmp', 'image/gif', 'image/jpeg', 'image/tiff']; //Extend as necessary 
var acceptedMimes = new Array();
for(i = ; i < imageMimes.length; i++) {
    if(canvas.toDataURL(imageMimes[i]).search(imageMimes[i])>=) {
        acceptedMimes[acceptedMimes.length] = imageMimes[i];
    }
}

You only need to run this once per page – it should never change through a page’s lifecycle.

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If you wish to make the user download the file as it is saved you can do the following:

var canvas = document.getElementById("mycanvas");
var image = canvas.toDataURL("image/png").replace("image/png", "image/octet-stream"); //Convert image to 'octet-stream' (Just a download, really)
window.location.href = image;

 

 

function exportCanvasAsPNG(id, fileName) {

    var canvasElement = document.getElementById(id);

    var MIME_TYPE = "image/png";

    var imgURL = canvasElement.toDataURL(MIME_TYPE);

    var dlLink = document.createElement('a');
    dlLink.download = fileName;
    dlLink.href = imgURL;
    dlLink.dataset.downloadurl = [MIME_TYPE, dlLink.download, dlLink.href].join(':');

    document.body.appendChild(dlLink);
    dlLink.click();
    document.body.removeChild(dlLink);
}

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