To get the image data URL of the canvas, we can use the toDataURL() method of the canvas object which converts the canvas drawing into a 64 bit encoded PNG URL. If you'd like for the image data URL to be in the jpeg format, you can pass image/jpeg as the first argument in the toDataURL() method. If you'd like to control the image quality for a jpeg image, you can pass in a number from 0 to 1 as the second argument to the toDataURL() method.
Note: The toDataURL() method requires that any images drawn onto the canvas are hosted on a web server with the same domain as the code executing it. If this condition is not met, a SECURITY_ERR exception is thrown.