How can I get an images data in base64 from a file input without FileReader() in Javascript?

问题

Is there a way to get the image data without FileReader()?

I'm looking for an older non-browser specific way to do it in javascript.

来源：https://stackoverflow.com/questions/20007106/how-can-i-get-an-images-data-in-base64-from-a-file-input-without-filereader-in