For more api, see here
const fs = require('fs');
const gm = require('gm');
gm('id.jpg')
.toBuffer('JPG', function (err, buffer) {
if (err) return console.error(err);
var base64data = new Buffer(buffer).toString('base64');
// Do whatever you want with the buffer, like a SOAPY and Fun request
console.log('base64data', base64data);
})
.thumb(350,350, 'thumbnail.jpg', 100, () => console.log('Tumbnail ready'))
.resize(110, 110)//max width
// Write resized image
.write('./resized.png', function (err) {
if (!err) console.log('done');
});