save html5 canvas element to file using webos

Question

here img variable is extracted from using Open Source Png Generation code here ..
http://www.xarg.org/2010/03/generate-client-side-png-files-using-javascript/ that is a

Answer 1

data is a string which starts with data:image/png;base64, and the rest is the data in base64.

1. Remove data:image/png;base64, from data
2. Convert it from base64 to binary
3. Save that binary buffer to file

Code

var buff = new Buffer(data.substr('data:image/png;base64,'.length), 'base64');
...
fs.write(id, buff, 0, buff.length, 0, function(...