CODEWITHSUNDEEP
javascriptgoogle-chromefirefoxhtml5-canvas
vbnet3d
vbnet3d

Reputation: 1151

Chrome: Tainted canvases may not be exported; Offline-only app

This question is similar, but not identical to many of the existing questions on this topic, including Tainted canvases may not be exported.

I am writing an offline-only app that has to stay that way and cannot use a local web server. Is there any way to circumvent the CORS check on the canvas in order to copy the data back to the base image.

Here is an example of the code I am trying:

var c1 = document.getElementById("tmp1");
var ctx1 = c1.getContext('2d');
var tmpImg1 = document.getElementById("tmpimg1");
ctx1.drawImage(img1, 0, 0, 150, 150);     
tmpImg1.src = c1.toDataURL();

The error message from Chrome is as follows:

Uncaught SecurityError: Failed to execute 'toDataURL' on 'HTMLCanvasElement': Tainted canvases may not be exported.

In an offline-only situation, what options are available that still have the same end result?

Upvotes: 1

Views: 5654

Answers (1)

markE
markE

Reputation: 105035

You could specify all your img.src as inline base64-encoded URLs. 

img.src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAgAAA ..."

This way all the imgs are local to your app and CORS is satisfied.

Upvotes: 2

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