Resize image using Graphicsmagick and upload using S3

imageResize.js

gm(request(url))
    .resize("80^", "80^")
    .stream(function (err, stdout, stderr) {
        var chunks = [];
        stdout.on('data', function (chunk) {
            chunks.push(chunk);
        });
        stdout.on('end', function () {
            var image = Buffer.concat(chunks);
            var options = {
                Bucket: "bucketName",
                Key: "filename.png",
                Body: image,
                ACL: "public-read",
                ContentLength: image.length,
                ContentType: "image/png"
            };
            s3bucket.putObject(options, function (err, res) {
                console.log(res);
            });
        });
    });