client.js

// HTML
// <input type='file' onchange="angular.element(this).scope().setImage(this)" style="width:350px; padding:5px; border:1px solid; border-color:#c3c3c3 #ddd #ddd #c3c3c3;" />

// JS
$scope.maximumImageSize = 5 * 1024 * 1024;
$scope.validImageExtensions = ['jpg', 'jpeg', 'bmp', 'gif', 'png'];

$scope.setImage = function(input) {

		if (input.files && input.files[0] && input.files[0].name) {

			var name = input.files[0].name;
			var extension = name.substring(name.lastIndexOf('.') + 1);

			if (!_.contains($scope.validImageExtensions, extension)) {
				var message = i18n.get('pageProposal.imageTypeError', {'name': name, 'valids': $scope.validImageExtensions.join(', ')});

				$timeout(function() {
					modalService.showMessage(i18n.get('text.info'), message);
				});
				return;
			}

			$timeout(function() {
				$scope.imageLoading = true;
			});
			var reader = new FileReader();

			reader.onload = function (event) {
				$timeout(function() {
					var data = event.target.result
					var matches = data.match(/^data:.+\/(.+);base64,(.*)$/);
					var ext = matches[1];
					var raw = matches[2];
					var size = (String(raw).length * 3 / 4) - (String(raw).match(/=/g) || []).length;

					if (size > $scope.maximumImageSize) {
						var message = i18n.get('pageProposal.imageSizeError', {'size': (size / (1024 * 1024)), 'max': ($scope.maximumImageSize / (1024 * 1024))});

						return modalService.showMessage(i18n.get('text.warn'), message);
					}
					$scope.post.image = data;
					$scope.imageLoading = false;
				}, 1000);
			}
			reader.readAsDataURL(input.files[0]);
		}
	};

config.js

var _ = require('underscore');

module.exports.base = {
	'proposal': {
		'imageTypes': ['jpg', 'jpeg', 'bmp', 'gif', 'png'],
		'imageMaximumSize': 5 * 1024 * 1024,
		'imageThumbnailWidth': 150
	},
	'blankImage': 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAQAAAAEACAYAAABccqhmAAABFUlEQVR4nO3BMQEAAADCoPVP7WsIoAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAeAMBPAABPO1TCQAAAABJRU5ErkJggg==',
	'generateTestUsers': true
};

module.exports.production = _.extend({}, module.exports.base, {
	'generateTestUsers': false
});

module.exports.appFog = _.extend({}, module.exports.base, {
	'generateTestUsers': false
});


module.exports.build = function() {

	var config = module.exports.base;

	if (process.env.NODE_ENV == 'production') {
		return module.exports.production;
	}
	if (process.env && process.env.VCAP_APP_PORT) {
		return module.exports.appFog;
	}
	return config;
};

module.exports = module.exports.build();

process.js

exports.save = function(request, response) {

	request.assert('text').notNull().notEmpty();
	request.assert('link').notNull().notEmpty();
	request.assert('image').notNull().notEmpty();

	var errors = request.validationErrors();
	if (errors) {
		util.log('Nova proposta: parâmetros inválidos. ' + util.inspect(errors));
		return response.json(500, {'message': 'Parâmetros inválidos'});
	}
	var error = exports.validaImage(request.param('image'));
	if (error) {
		util.log('Nova proposta: imagem inválida. ' + error);
		return response.json(500, {'message': error});
	}
	var text = request.param('text');
	var link = request.param('miniUrl');
	var image = request.param('image');

	var proposal = {
		'id': utils.uid(7) + '-' + utils.uid(5) + '-' + utils.uid(7),
		'post': {
			'text': text,
			'image': image,
			'link': link
		}
	};

	util.log(util.format('Gerando miniatura para a proposta de "%s" para "%s".', email, id));

	utils.generateThumnail(image, 200, function(err, thumbnail) {
		proposal.post.thumbnail = thumbnail;

		// salva proposal no BD
	});
};

exports.validateImage = function(image) {

	if (!image) {
		return null;
	}

	var matches = image.match(/^data:.+\/(.+);base64,(.*)$/);
	var type = matches[1];
	var data = matches[2];
	var size = (String(data).length * 3 / 4) - (String(data).match(/=/g) || []).length;

	if (size > config.proposal.imageMaximumSize) {
		return util.format('Tamanho máximo da imagem é %sMB, a imagem tem %sMB.', (config.proposal.imageMaximumSize / (1024 * 1024)), (size / (1024 * 1024)));
	}
	if (!_.contains(config.proposal.imageTypes, type)) {
		return util.format('Imagem inválida. Tipo %s. Tipos válidos %s.', type, config.proposal.imageTypes.join(', '));
	}
	return null;
};

server.js

exports.image = function(request, response) {
	request.assert('id').notNull();

	var errors = request.validationErrors();
	if (errors) {
		util.log('Imagem: parâmetros inválidos. ' + util.inspect(errors));
		return response.json(500, {'message': 'Parâmetros inválidos'});
	}
	var id = request.param('id');

	repository.findOneProto('proposal', {'id': id}, function(err, proposal) {
		var imageInBase64 = config.blankImage;
		if (!err && proposal && proposal.post && proposal.post.image) {
			imageInBase64 = proposal.post.image;
		}

		var matches = imageInBase64.match(/^data:.+\/(.+);base64,(.*)$/);
		var ext = matches[1];
		var data = matches[2];

		var imageBuffer = new Buffer(data, 'base64');
		response.setHeader('Content-Type', 'image/png');
		response.setHeader('Content-Length', imageBuffer.length);
		response.end(imageBuffer, 'binary');
	});
};

utils.js

var crypto = require('crypto'),
	im = require('imagemagick');

https.globalAgent.options.secureProtocol = 'SSLv3_method';
https.globalAgent.options.rejectUnauthorized = false;

exports.generateThumnail = function(image, size, callback) {

	if (!image) {
		return callback(null, null);
	}

	var matches = image.match(/^data:.+\/(.+);base64,(.*)$/);
	var data = matches[2];

	im.resize({
		srcData: new Buffer(data, 'base64').toString('binary'),
		width: size
	}, function(err, stdout, stderr) {
		if (err) {
			return callback(err);
		}
		callback(null, 'data:image/png;base64,' + new Buffer(stdout, 'binary').toString('base64'))
	});
};

exports.md5 = function(text) {
	return exports.digest(text, 'md5', 'hex');
};

exports.sha1 = function(text) {
	return exports.digest(text, 'sha1', 'hex');
};

exports.digest = function(text, hash, mode) {
	return crypto.createHash(hash).update(text).digest(mode);
};

exports.uid = function(size) {
  return crypto.randomBytes(parseInt(size/2)).toString('hex');
};

exports.gravatarHash = function(email) {
	return exports.md5(String(email).trim().toLowerCase());
};