在firefox上将图像转换为base64 javascript

Question

I need to convert image that are in a webpage to base64 over greasemonkey or firefox .xpi extension. How can i do it? I know that i have btoa() function, but i only can use it with strings, not with images. Little help here. Thanks.

Answer 1

You could use the canvas element and draw the image using drawImage() onto it, then use toDataURL() to get the base64 encoded image.

see: https://developer.mozilla.org/en/html/canvas