encode image file by base64

decode-base64.js

var fs = require('fs');

if (process.argv.length < 3) {
	throw new Error('Input file name');
}

var f = process.argv[2];

fs.readFile(f, 'utf8', function (err, data) {
	if (err) {
		throw err;
	}

	var decodedImage = new Buffer(data, 'base64');

	fs.writeFile('decoded-' + f, decodedImage, 'binary', function (err) {});
});

encode-base64.js

var fs = require('fs');
 
if (process.argv.length < 3) {
	throw new Error('Input file name');
}
 
var f = process.argv[2];
 
fs.readFile(f, function (err, data) {
	if (err) {
		throw err;
	}
 
	var base64Image = new Buffer(data).toString('base64');
	
	fs.writeFile('encoded-' + f, base64Image, 'binary', function (err) {});
});