Node.js和OpenCV

Question

我在从npm opencv软件包中获取面部跟踪和检测时遇到麻烦。 我目前正试图在每个面上绘制一个圆圈。

我在错误下面列出了该错误以及下面的文件。 我不确定它是否只是一个有约束力的问题，如果是这样，我应该采取什么步骤来解决它。

通过brew FYI安装了OpenCV（2.4.8.2）-我猜可能是版本问题

错误：

/Users/gwilliams2/Sites/facetracking/node_modules/opencv/lib/opencv.js:29
      var face_cascade = new cv.CascadeClassifier(classifier);
                         ^
TypeError: Error loading file
    at Matrix.matrix.detectObject (/Users/gwilliams2/Sites/facetracking/node_modules/opencv/lib/opencv.js:29:23)
    at /Users/gwilliams2/Sites/facetracking/server.js:170:8
    at Socket.<anonymous> (/Users/gwilliams2/Sites/facetracking/server.js:161:11)
    at Socket.EventEmitter.emit [as $emit] (events.js:95:17)
    at SocketNamespace.handlePacket (/Users/gwilliams2/Sites/facetracking/node_modules/socket.io/lib/namespace.js:335:22)
    at Manager.onClientMessage (/Users/gwilliams2/Sites/facetracking/node_modules/socket.io/lib/manager.js:488:38)
    at WebSocket.Transport.onMessage (/Users/gwilliams2/Sites/facetracking/node_modules/socket.io/lib/transport.js:387:20)
    at Parser.<anonymous> (/Users/gwilliams2/Sites/facetracking/node_modules/socket.io/lib/transports/websocket/hybi-16.js:39:10)
    at Parser.EventEmitter.emit (events.js:95:17)
    at finish (/Users/gwilliams2/Sites/facetracking/node_modules/socket.io/lib/transports/websocket/hybi-16.js:288:16)

client.js

var APP = {

    // setup the web socket
    socket: io.connect('http://gaz.local:3000'),
    video: null,
    canvas: null,
    imgData: null,

    init: function (){

        // get elements
        APP.video = $('#myVideo')[0];
        APP.canvas = $('#myCanvas')[0];

        // start app
        APP.main();

    },

    main: function(){

      // if we can get a webcam
      if(APP.hasGetUserMedia()){

          navigator.webkitGetUserMedia(
                  {video:true, audio:false},
                  APP.videoSuccess,
                  APP.videoError
              );

      } else {

          alert('Sorry, you do not have webcam access');
      }

    },

    hasGetUserMedia: function (){

      return !!(navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia);

    },

    videoSuccess: function (stream){

      // set the video to stream
      APP.video.src = window.URL.createObjectURL(stream);

      // set canvas size
      APP.canvas.width = APP.video.width;
      APP.canvas.height = APP.video.height;

      // draw video
      var i = 0;
      setTimeout(function(){

        // darw the image to the canvas
        APP.canvas.getContext('2d').drawImage(APP.video, 0, 0);

        APP.imgData = APP.canvas.toDataURL('image/jpeg');
        APP.imgData = APP.imgData.replace('data:image/jpeg;base64,', '');

        // send the file in json format to the server
        var jsonData = JSON.stringify({imgData: APP.imgData, count: i});
        APP.socket.emit('update', jsonData);

        // APP.socket.on('put_down', function (data) {
        //   console.log(data);
        // });


        // update the counter
        i++;

      }, 50);

    },

    videoError: function (err){
      alert('Error: ' + err);
    },

};

$(function (){ APP.init(); });

Server.js

/*
    Setup a server, RTC and face tracking

    Install opencv
        brew install opencv
    NPM
        https://www.npmjs.org/package/fs
        https://www.npmjs.org/package/http
        https://www.npmjs.org/package/express
        https://www.npmjs.org/package/socket.io
        https://www.npmjs.org/package/opencv
*/
var APP = {

    // include some scripts
    server: null,
    port: 3000,
    express: require('express'),
    app: null,
    mdb: require('mongodb'),
    dbUrl: 'mongodb://127.0.0.1:27017/test',
    db: null,
    io: null,
    cv: require('opencv'),
    fs: require("fs"),

    init: function (){

        // connect stuff up
        APP.app = APP.express();
        APP.server = require('http').createServer(APP.app).listen(APP.port, '0.0.0.0');
        APP.io = require('socket.io').listen(APP.server);

        // http routing
        APP.routing();

        // connect the websocket
        APP.io.on('connection', function (socket){

            console.log('Server started on port ' + APP.port);
            APP.main(socket);

        });

    },

    // open the db
    openDB: function (){

        APP.mdb.connect(APP.dbURL, function(err, db){

            if(err)
                throw err;

            APP.db = db;

        });

    },

    // close the db
    closeDB: function (){

        APP.db.close();

    },

    // insert a file to the db
    dbInsert: function (col, data){

        // open the db
        APP.openDB();

        var collection = APP.db.collection(col);
        collection.insert(data, function(err, docs){
            if(err){
                console.warn(err.message);
            } else {
                console.log('Successfully inserted record');
            }
        });

        // close the db
        APP.closeDB();

    },

    // insert a file to the db
    dbUpdate: function (col, crit, data){

        // open the db
        APP.openDB();

        var collection = APP.db.collection(col);
        collection.update(crit, {$set: {hi: 'there'}}, {w:1}, function (){
            if(err){
                console.warn(err.message);
            } else {
                console.log('Successfully updated record');
            }
        });

        // close the db
        APP.closeDB();

    },

    // find a file in the db
    dbFind: function (col){

        // open the db
        APP.openDB();

        var collection = APP.db.collection(col);
        collection.find().toArray(function(err, results) {
            console.dir(results);
        });

        // close the db
        APP.closeDB();

    },

    // routing files
    routing: function (){

        // set directory to use for files prefixed with /library
        APP.app.use('/library', APP.express.static(__dirname + '/library'));

        // index page
        APP.app.get('/*', function (req, res){

            // get query
            // console.log(req.query);

            // get file
            res.sendfile(__dirname + '/' + req.route.params);

        });

    },

    main: function (socket){

        //  APP.io.sockets.emit('put_down', {'fingers': 's'});
        socket.on('update', function (data) {

            // console.log(data);

            // get the data
            data = JSON.parse(data);

            // create the file
            var filename = 'file' + data.count + '.jpg';
            APP.fs.writeFile(filename, data.imgData, 'base64', function(err) {
                if(err)
                    console.log(err);
            });

            // open file with open cv
            APP.cv.readImage(filename, function(err, im){

                // handle errors
                if(err)
                    return err;

                console.log(im);

                // /Users/gwilliams2/Sites/facetracking/node_modules/opencv/data/haarcascade_frontalface_default.xml
                im.detectObject('./haarcascade_frontalface_default.xml', {}, function(err, faces){
                    for (var i=0;i<faces.length; i++){
                        var x = faces[i];
                        im.ellipse(x.x + x.width/2, x.y + x.height/2, x.width/2, x.height/2);
                    }

                    im.save('./out.png');   
                });

            });

        });

    }

};

// run the script
APP.init();

Answer 1

解决了，首先，我已错误地链接到xml文件，因为路径不正确，如上面的注释中所建议。 然后，我注意到打开文件的缓冲区已关闭。 由于所有内容都是异步的，因此服务器中用于分析文件的代码需要嵌套在文件保存回调中。