Merge pull request #29 from serratus/upc-barcode

UPC-A, UPC-E and EAN-8 support and further improving overall robustness. Closes #24

README.md

@@ -7,10 +7,11 @@ quaggaJS
 
 QuaggaJS is a barcode-scanner entirely written in JavaScript supporting real-
 time localization and decoding of various types of barcodes such as __EAN__,
-__CODE128__, __CODE39__ and __CODABAR__. The library is also capable of using `getUserMedia`
-to get direct access to the user's camera stream. Although the code relies on
-heavy image-processing even recent smartphones are capable of locating and
-decoding barcodes in real-time.
+__CODE 128__, __CODE 39__, __EAN 8__, __UPC-A__, __UPC-C__ and  __CODABAR__.
+The library is also capable of using `getUserMedia` to get direct access to
+the user's camera stream. Although the code relies on heavy image-processing
+even recent smartphones are capable of locating and decoding barcodes in
+real-time.
 
 Try some [examples](http://serratus.github.io/quaggaJS/examples) and check out
 the blog post ([How barcode-localization works in QuaggaJS][oberhofer_co_how])
@@ -292,6 +293,14 @@ work.
 
 ## <a name="changelog">Changelog</a>
 
+### 2015-04-30
+- Features
+  - Added support for [UPC-A and UPC-E][upc_wiki] barcodes
+  - Added support for [EAN-8][ean_8_wiki] barcodes
+- Improvements
+  - Added extended configuration to the live-video example
+  - Releasing resources when calling ``Quagga.stop()``
+
 ### 2015-04-25
 - Improvements
   - Added extended configuration to the file-input example

dist/quagga.js

@@ -1240,23 +1240,50 @@ define(
             throw BarcodeReader.PatternNotFoundException;
         };
 
-        EANReader.prototype._decode = function() {
-            var startInfo,
-                self = this,
-                code = null, 
-                result = [],
-                i,
-                codeFrequency = 0x0,
-                decodedCodes = [];
+        EANReader.prototype._findStart = function() {
+            var self = this,
+                leadingWhitespaceStart,
+                offset = self._nextSet(self._row),
+                startInfo;
 
-            try {
-                startInfo = self._findPattern(self.START_PATTERN);
-                code = {
-                    code : startInfo.code,
-                    start : startInfo.start,
-                    end : startInfo.end
+            while(!startInfo) {
+                startInfo = self._findPattern(self.START_PATTERN, offset);
+                leadingWhitespaceStart = startInfo.start - (startInfo.end - startInfo.start);
+                if (leadingWhitespaceStart >= 0) {
+                    if (self._matchRange(leadingWhitespaceStart, startInfo.start, 0)) {
+                        return startInfo;
+                    }
+                }
+                offset = startInfo.end;
+                startInfo = null;
+            }
         };
-                decodedCodes.push(code);
+
+        EANReader.prototype._verifyTrailingWhitespace = function(endInfo) {
+            var self = this,
+                trailingWhitespaceEnd;
+
+            trailingWhitespaceEnd = endInfo.end + (endInfo.end - endInfo.start);
+            if (trailingWhitespaceEnd < self._row.length) {
+                if (self._matchRange(endInfo.end, trailingWhitespaceEnd, 0)) {
+                    return endInfo;
+                }
+            }
+            return null;
+        };
+
+        EANReader.prototype._findEnd = function(offset, isWhite) {
+            var self = this,
+                endInfo = self._findPattern(self.STOP_PATTERN, offset, isWhite, false);
+
+            return self._verifyTrailingWhitespace(endInfo);
+        };
+
+        EANReader.prototype._decodePayload = function(code, result, decodedCodes) {
+            var i,
+                self = this,
+                codeFrequency = 0x0;
+
             for ( i = 0; i < 6; i++) {
                 code = self._decodeCode(code.end);
                 if (code.code >= self.CODE_G_START) {
@@ -1276,7 +1303,7 @@ define(
                 }
             }
 
-                code = self._findPattern(self.MIDDLE_PATTERN, code.end, true);
+            code = self._findPattern(self.MIDDLE_PATTERN, code.end, true, false);
             if (code === null) {
                 return null;
             }
@@ -1288,7 +1315,30 @@ define(
                 result.push(code.code);
             }
 
-                code = self._findPattern(self.STOP_PATTERN, code.end);
+            return code;
+        };
+
+        EANReader.prototype._decode = function() {
+            var startInfo,
+                self = this,
+                code = null, 
+                result = [],
+                decodedCodes = [];
+
+            try {
+                startInfo = self._findStart();
+                code = {
+                    code : startInfo.code,
+                    start : startInfo.start,
+                    end : startInfo.end
+                };
+                decodedCodes.push(code);
+                code = self._decodePayload(code, result, decodedCodes);
+                code = self._findEnd(code.end, false);
+                if (!code){
+                    return null;
+                }
+
                 decodedCodes.push(code);
 
                 // Checksum
@@ -1459,6 +1509,17 @@ define('input_stream',["image_loader"], function(ImageLoader) {
             }
         };
 
+        that.clearEventHandlers = function() {
+            _eventNames.forEach(function(eventName) {
+                var handlers = _eventHandlers[eventName];
+                if (handlers && handlers.length > 0) {
+                    handlers.forEach(function(handler) {
+                        video.removeEventListener(eventName, handler);
+                    });
+                }
+            });
+        };
+
         that.trigger = function(eventName, args) {
             var j,
                 handlers = _eventHandlers[eventName];
@@ -6384,23 +6445,23 @@ define('bresenham',[],function() {
             extrema = [],
             currentDir,
             dir,
-            threshold = (max - min) / 8,
+            threshold = (max - min) / 12,
             rThreshold = -threshold,
             i,
             j;
 
         // 1. find extrema
-        currentDir = line[0] > center ? Slope.DIR.DOWN : Slope.DIR.UP;
+        currentDir = line[0] > center ? Slope.DIR.UP : Slope.DIR.DOWN;
         extrema.push({
             pos : 0,
             val : line[0]
         });
         for ( i = 0; i < line.length - 1; i++) {
             slope = (line[i + 1] - line[i]);
-            if (slope < rThreshold) {
-                dir = Slope.DIR.UP;
-            } else if (slope > threshold) {
+            if (slope < rThreshold && line[i + 1] < (center*1.5)) {
                 dir = Slope.DIR.DOWN;
+            } else if (slope > threshold && line[i + 1] > (center*0.5)) {
+                dir = Slope.DIR.UP;
             } else {
                 dir = currentDir;
             }
@@ -6995,14 +7056,221 @@ define(
 /* jshint undef: true, unused: true, browser:true, devel: true */
 /* global define */
 
-define('barcode_decoder',["bresenham", "image_debug", 'code_128_reader', 'ean_reader', 'code_39_reader', 'codabar_reader'], function(Bresenham, ImageDebug, Code128Reader, EANReader, Code39Reader, CodabarReader) {
+define(
+    'upc_reader',[
+        "./ean_reader"
+    ],
+    function(EANReader) {
+        
+
+        function UPCReader() {
+            EANReader.call(this);
+        }
+
+        UPCReader.prototype = Object.create(EANReader.prototype);
+        UPCReader.prototype.constructor = UPCReader;
+
+        UPCReader.prototype._decode = function() {
+            var result = EANReader.prototype._decode.call(this);
+
+            if (result && result.code && result.code.length === 13 && result.code.charAt(0) === "0") {
+
+                result.code = result.code.substring(1);
+                return result;
+            }
+            return null;
+        };
+
+        return (UPCReader);
+    }
+);
+/* jshint undef: true, unused: true, browser:true, devel: true */
+/* global define */
+
+define(
+    'ean_8_reader',[
+        "./ean_reader"
+    ],
+    function(EANReader) {
+        
+
+        function EAN8Reader() {
+            EANReader.call(this);
+        }
+
+        EAN8Reader.prototype = Object.create(EANReader.prototype);
+        EAN8Reader.prototype.constructor = EAN8Reader;
+
+        EAN8Reader.prototype._decodePayload = function(code, result, decodedCodes) {
+            var i,
+                self = this;
+
+            for ( i = 0; i < 4; i++) {
+                code = self._decodeCode(code.end);
+                result.push(code.code);
+                decodedCodes.push(code);
+            }
+
+            code = self._findPattern(self.MIDDLE_PATTERN, code.end, true);
+            if (code === null) {
+                return null;
+            }
+            decodedCodes.push(code);
+
+            for ( i = 0; i < 4; i++) {
+                code = self._decodeCode(code.end, self.CODE_G_START);
+                decodedCodes.push(code);
+                result.push(code.code);
+            }
+
+            return code;
+        };
+
+        return (EAN8Reader);
+    }
+);
+/* jshint undef: true, unused: true, browser:true, devel: true */
+/* global define */
+
+define(
+    'upc_e_reader',[
+        "./ean_reader"
+    ],
+    function(EANReader) {
+        
+
+        function UPCEReader() {
+            EANReader.call(this);
+        }
+
+        var properties = {
+            CODE_FREQUENCY : {value: [
+                [ 56, 52, 50, 49, 44, 38, 35, 42, 41, 37 ],
+                [7, 11, 13, 14, 19, 25, 28, 21, 22, 26]]},
+            STOP_PATTERN: { value: [1 / 6 * 7, 1 / 6 * 7, 1 / 6 * 7, 1 / 6 * 7, 1 / 6 * 7, 1 / 6 * 7]}
+        };
+
+        UPCEReader.prototype = Object.create(EANReader.prototype, properties);
+        UPCEReader.prototype.constructor = UPCEReader;
+
+        UPCEReader.prototype._decodePayload = function(code, result, decodedCodes) {
+            var i,
+                self = this,
+                codeFrequency = 0x0;
+
+            for ( i = 0; i < 6; i++) {
+                code = self._decodeCode(code.end);
+                if (code.code >= self.CODE_G_START) {
+                    code.code = code.code - self.CODE_G_START;
+                    codeFrequency |= 1 << (5 - i);
+                } else {
+                    codeFrequency |= 0 << (5 - i);
+                }
+                result.push(code.code);
+                decodedCodes.push(code);
+            }
+            self._determineParity(codeFrequency, result);
+
+            return code;
+        };
+
+        UPCEReader.prototype._determineParity = function(codeFrequency, result) {
+            var self =this,
+                i,
+                nrSystem;
+
+            for (nrSystem = 0; nrSystem < self.CODE_FREQUENCY.length; nrSystem++){
+                for ( i = 0; i < self.CODE_FREQUENCY[nrSystem].length; i++) {
+                    if (codeFrequency === self.CODE_FREQUENCY[nrSystem][i]) {
+                        result.unshift(nrSystem);
+                        result.push(i);
+                        return;
+                    }
+                }
+            }
+        };
+
+        UPCEReader.prototype._convertToUPCA = function(result) {
+            var upca = [result[0]],
+                lastDigit = result[result.length - 2];
+
+            if (lastDigit <= 2) {
+                upca = upca.concat(result.slice(1, 3))
+                    .concat([lastDigit, 0, 0, 0, 0])
+                    .concat(result.slice(3, 6));
+            } else if (lastDigit === 3) {
+                upca = upca.concat(result.slice(1, 4))
+                    .concat([0 ,0, 0, 0, 0])
+                    .concat(result.slice(4,6));
+            } else if (lastDigit === 4) {
+                upca = upca.concat(result.slice(1, 5))
+                    .concat([0, 0, 0, 0, 0, result[5]]);
+            } else {
+                upca = upca.concat(result.slice(1, 6))
+                    .concat([0, 0, 0, 0, lastDigit]);
+            }
+
+            upca.push(result[result.length - 1]);
+            return upca;
+        };
+
+        UPCEReader.prototype._checksum = function(result) {
+            return EANReader.prototype._checksum.call(this, this._convertToUPCA(result));
+        };
+
+        UPCEReader.prototype._findEnd = function(offset, isWhite) {
+            isWhite = true;
+            return EANReader.prototype._findEnd.call(this, offset, isWhite);
+        };
+
+        UPCEReader.prototype._verifyTrailingWhitespace = function(endInfo) {
+            var self = this,
+                trailingWhitespaceEnd;
+
+            trailingWhitespaceEnd = endInfo.end + ((endInfo.end - endInfo.start)/2);
+            if (trailingWhitespaceEnd < self._row.length) {
+                if (self._matchRange(endInfo.end, trailingWhitespaceEnd, 0)) {
+                    return endInfo;
+                }
+            }
+        };
+
+        return (UPCEReader);
+    }
+);
+/* jshint undef: true, unused: true, browser:true, devel: true */
+/* global define */
+
+define('barcode_decoder',[
+    "bresenham",
+    "image_debug",
+    'code_128_reader',
+    'ean_reader',
+    'code_39_reader',
+    'codabar_reader',
+    'upc_reader',
+    'ean_8_reader',
+    'upc_e_reader'
+], function(
+    Bresenham,
+    ImageDebug,
+    Code128Reader,
+    EANReader,
+    Code39Reader,
+    CodabarReader,
+    UPCReader,
+    EAN8Reader,
+    UPCEReader) {
     
     
     var readers = {
         code_128_reader: Code128Reader,
         ean_reader: EANReader,
+        ean_8_reader: EAN8Reader,
         code_39_reader: Code39Reader,
-        codabar_reader: CodabarReader
+        codabar_reader: CodabarReader,
+        upc_reader: UPCReader,
+        upc_e_reader: UPCEReader
     };
     var BarcodeDecoder = {
         create : function(config, inputImageWrapper) {
@@ -7090,18 +7358,25 @@ define('barcode_decoder',["bresenham", "image_debug", 'code_128_reader', 'ean_re
              * @param {Number} angle 
              */
             function getExtendedLine(line, angle, ext) {
+                function extendLine(amount) {
                     var extension = {
-                        y : ext * Math.sin(angle),
-                        x : ext * Math.cos(angle)
+                        y : amount * Math.sin(angle),
+                        x : amount * Math.cos(angle)
                     };
 
                     line[0].y -= extension.y;
                     line[0].x -= extension.x;
                     line[1].y += extension.y;
                     line[1].x += extension.x;
+                }
 
                 // check if inside image
-                if (!inputImageWrapper.inImageWithBorder(line[0], 0) || !inputImageWrapper.inImageWithBorder(line[1], 0)) {
+                extendLine(ext);
+                while (ext > 1 && !inputImageWrapper.inImageWithBorder(line[0], 0) || !inputImageWrapper.inImageWithBorder(line[1], 0)) {
+                    ext -= Math.floor(ext/2);
+                    extendLine(-ext);
+                }
+                if (ext <= 1) {
                     return null;
                 }
                 return line;
@@ -7181,6 +7456,12 @@ define('barcode_decoder',["bresenham", "image_debug", 'code_128_reader', 'ean_re
                 return result;
             }
 
+            function getLineLength(line) {
+                return Math.sqrt(
+                    Math.pow(Math.abs(line[1].y - line[0].y), 2) +
+                    Math.pow(Math.abs(line[1].x - line[0].x), 2));
+            }
+
             /**
              * With the help of the configured readers (Code128 or EAN) this function tries to detect a 
              * valid barcode pattern within the given area.
@@ -7191,15 +7472,17 @@ define('barcode_decoder',["bresenham", "image_debug", 'code_128_reader', 'ean_re
                 var line,
                     lineAngle,
                     ctx = _canvas.ctx.overlay,
-                    result;
+                    result,
+                    lineLength;
 
                 if (config.drawBoundingBox && ctx) {
                     ImageDebug.drawPath(box, {x: 0, y: 1}, ctx, {color: "blue", lineWidth: 2});
                 }
 
                 line = getLine(box);
+                lineLength = getLineLength(line);
                 lineAngle = Math.atan2(line[1].y - line[0].y, line[1].x - line[0].x);
-                line = getExtendedLine(line, lineAngle, 10);
+                line = getExtendedLine(line, lineAngle, Math.floor(lineLength*0.1));
                 if(line === null){
                     return null;
                 }
@@ -7531,7 +7814,8 @@ define('events',[],function() {
 
 define('camera_access',["html_utils"], function(HtmlUtils) {
     
-    var streamRef;
+    var streamRef,
+        loadedDataHandler;
     
     /**
      * Wraps browser-specific getUserMedia
@@ -7547,17 +7831,7 @@ define('camera_access',["html_utils"], function(HtmlUtils) {
         }, failure);
     }
 
-    /**
-     * Tries to attach the camera-stream to a given video-element
-     * and calls the callback function when the content is ready
-     * @param {Object} constraints
-     * @param {Object} video
-     * @param {Object} callback
-     */
-    function initCamera(constraints, video, callback) {
-        getUserMedia(constraints, function(src) {
-            video.src = src;
-            video.addEventListener('loadeddata', function() {
+    function loadedData(video, callback) {
         var attempts = 10;
 
         function checkVideo() {
@@ -7573,9 +7847,24 @@ define('camera_access',["html_utils"], function(HtmlUtils) {
             }
             attempts--;
         }
-
         checkVideo();
-            }, false);
+    }
+
+    /**
+     * Tries to attach the camera-stream to a given video-element
+     * and calls the callback function when the content is ready
+     * @param {Object} constraints
+     * @param {Object} video
+     * @param {Object} callback
+     */
+    function initCamera(constraints, video, callback) {
+        getUserMedia(constraints, function(src) {
+            video.src = src;
+            if (loadedDataHandler) {
+                video.removeEventListener("loadeddata", loadedDataHandler, false);
+            }
+            loadedDataHandler = loadedData.bind(null, video, callback);
+            video.addEventListener('loadeddata', loadedDataHandler, false);
             video.play();
         }, function(e) {
             console.log(e);
@@ -8064,8 +8353,14 @@ function(Code128Reader,
         },
         stop : function() {
             _stopped = true;
+            _workerPool.forEach(function(workerThread) {
+                workerThread.worker.terminate();
+                console.log("Worker terminated!");
+            });
+            _workerPool.length = 0;
             if (_config.inputStream.type === "LiveStream") {
                 CameraAccess.release();
+                _inputStream.clearEventHandlers();
             }
         },
         pause: function() {

example/camera_example.html

@@ -0,0 +1,83 @@
+<!DOCTYPE html>
+<html lang="en">
+    <head>
+        <meta charset="utf-8" />
+        <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />
+
+        <title>Camera</title>
+        <script type="text/javascript">
+            navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;
+            window.URL = window.URL || window.webkitURL || window.mozURL || window.msURL;
+
+            function getUserMedia(constraints, success, failure) {
+                navigator.getUserMedia(constraints, function(stream) {
+                    var videoSrc = (window.URL && window.URL.createObjectURL(stream)) || stream;
+                    success.apply(null, [videoSrc]);
+                }, failure);
+            }
+
+
+            function initCamera(constraints, video, callback) {
+                getUserMedia(constraints, function (src) {
+                    video.src = src;
+                    video.addEventListener('loadeddata', function() {
+                        var attempts = 10;
+
+                        function checkVideo() {
+                            if (attempts > 0) {
+                                if (video.videoWidth > 0 && video.videoHeight > 0) {
+                                    console.log(video.videoWidth + "px x " + video.videoHeight + "px");
+                                    video.play();
+                                    callback();
+                                } else {
+                                    window.setTimeout(checkVideo, 100);
+                                }
+                            } else {
+                                callback('Unable to play video stream.');
+                            }
+                            attempts--;
+                        }
+
+                        checkVideo();
+                    }, false);
+                }, function(e) {
+                    console.log(e);
+                });
+            }
+
+            function copyToCanvas(video, ctx) {
+                ( function frame() {
+                    ctx.drawImage(video, 0, 0);
+                    window.requestAnimationFrame(frame);
+                }());
+            }
+
+            window.addEventListener('load', function() {
+                var constraints = {
+                            video: {
+                                mandatory: {
+                                    minWidth: 1280,
+                                    minHeight: 720
+                                }
+                            }
+                        },
+                        video = document.createElement('video'),
+                        canvas = document.createElement('canvas');
+
+                document.body.appendChild(video);
+                document.body.appendChild(canvas);
+
+                initCamera(constraints, video, function() {
+                    canvas.setAttribute('width', video.videoWidth);
+                    canvas.setAttribute('height', video.videoHeight);
+                    copyToCanvas(video, canvas.getContext('2d'));
+                });
+            }, false);
+
+
+        </script>
+    </head>
+    <body>
+
+    </body>
+</html>

example/file_input.html

@@ -45,6 +45,9 @@
                     <option value="code_128" selected="selected">Code 128</option>
                     <option value="code_39">Code 39</option>
                     <option value="ean">EAN</option>
+                    <option value="ean_8">EAN-8</option>
+                    <option value="upc">UPC</option>
+                    <option value="upc_e">UPC-E</option>
                     <option value="codabar">Codabar</option>
                 </select>
             </label>
@@ -52,8 +55,8 @@
                 <span>Resolution (long side)</span>
                 <select name="input-stream_size">
                     <option value="320">320px</option>
-                    <option value="640">640px</option>
-                    <option selected="selected" value="800">800px</option>
+                    <option selected="selected" value="640">640px</option>
+                    <option value="800">800px</option>
                     <option value="1280">1280px</option>
                     <option value="1600">1600px</option>
                     <option value="1920">1920px</option>
@@ -64,8 +67,8 @@
                 <select name="locator_patch-size">
                     <option value="x-small">x-small</option>
                     <option value="small">small</option>
-                    <option selected="selected" value="medium">medium</option>
-                    <option value="large">large</option>
+                    <option value="medium">medium</option>
+                    <option selected="selected" value="large">large</option>
                     <option value="x-large">x-large</option>
                 </select>
             </label>
@@ -76,8 +79,8 @@
             <label>
                 <span>Workers</span>
                 <select name="numOfWorkers">
-                    <option value="0">0</option>
-                    <option value="1" selected="selected">1</option>
+                    <option selected="selected" value="0">0</option>
+                    <option value="1">1</option>
                     <option value="2">2</option>
                     <option value="4">4</option>
                     <option value="8">8</option>

example/file_input.js

@@ -3,10 +3,6 @@ $(function() {
         init: function() {
             App.attachListeners();
         },
-        config: {
-            reader: "code_128",
-            length: 10
-        },
         attachListeners: function() {
             var self = this;
 
@@ -92,15 +88,17 @@ $(function() {
         },
         state: {
             inputStream: {
-                size: 800
+                size: 640
             },
             locator: {
-                patchSize: "medium",
+                patchSize: "large",
                 halfSample: false
             },
-            numOfWorkers: 1,
+            numOfWorkers: 0,
             decoder: {
-                readers: ["code_128_reader"]
+                readers: ["code_128_reader"],
+                showFrequency: true,
+                showPattern: true
             },
             locate: true,
             src: null

example/live_w_locator.html

@@ -27,16 +27,58 @@
             It works best if your camera has built-in auto-focus.
             </p>
         <div class="controls">
+            <fieldset class="input-group">
                 <button class="stop">Stop</button>
-        <fieldset class="reader-group">
-            <label>Code128</label>
-            <input type="radio" name="reader" value="code_128" checked />
-            <label>EAN</label>
-            <input type="radio" name="reader" value="ean" />
-            <label>Code39</label>
-            <input type="radio" name="reader" value="code_39" />
             </fieldset>
-        <br clear="all" />
+            <fieldset class="reader-config-group">
+                <label>
+                    <span>Barcode-Type</span>
+                    <select name="decoder_readers">
+                        <option value="code_128" selected="selected">Code 128</option>
+                        <option value="code_39">Code 39</option>
+                        <option value="ean">EAN</option>
+                        <option value="ean_8">EAN-8</option>
+                        <option value="upc">UPC</option>
+                        <option value="upc_e">UPC-E</option>
+                        <option value="codabar">Codabar</option>
+                    </select>
+                </label>
+                <label>
+                    <span>Resolution (long side)</span>
+                    <select name="input-stream_constraints">
+                        <option value="320x240">320px</option>
+                        <option selected="selected" value="640x480">640px</option>
+                        <option value="800x600">800px</option>
+                        <option value="1280x720">1280px</option>
+                        <option value="1600x960">1600px</option>
+                        <option value="1920x1080">1920px</option>
+                    </select>
+                </label>
+                <label>
+                    <span>Patch-Size</span>
+                    <select name="locator_patch-size">
+                        <option value="x-small">x-small</option>
+                        <option value="small">small</option>
+                        <option selected="selected" value="medium">medium</option>
+                        <option value="large">large</option>
+                        <option value="x-large">x-large</option>
+                    </select>
+                </label>
+                <label>
+                    <span>Half-Sample</span>
+                    <input type="checkbox" checked="checked" name="locator_half-sample" />
+                </label>
+                <label>
+                    <span>Workers</span>
+                    <select name="numOfWorkers">
+                        <option value="0">0</option>
+                        <option value="1">1</option>
+                        <option value="2">2</option>
+                        <option selected="selected" value="4">4</option>
+                        <option value="8">8</option>
+                    </select>
+                </label>
+            </fieldset>
         </div>
       <div id="result_strip">
         <ul class="thumbnails"></ul>
@@ -50,7 +92,7 @@
       </footer>
     
     <script src="../src/vendor/jquery-1.9.0.min.js" type="text/javascript"></script>
-    <script src="../dist/quagga.min.js" type="text/javascript"></script>
+    <script src="../dist/quagga.js" type="text/javascript"></script>
     <script src="live_w_locator.js" type="text/javascript"></script>
   </body>
 </html>

example/live_w_locator.js

@@ -1,33 +1,103 @@
 $(function() {
     var App = {
         init : function() {
-            Quagga.init({
-                inputStream : {
-                    name : "Live",
-                    type : "LiveStream"
-                },
-                decoder : {
-                    readers : ["code_128_reader"]
-                }
-            }, function() {
+            Quagga.init(this.state, function() {
                 App.attachListeners();
                 Quagga.start();
             });
         },
-        attachListeners : function() {
-            $(".controls .reader-group").on("change", "input", function(e) {
-                e.preventDefault();
-                Quagga.setReaders([e.target.value + "_reader"]);
-            });
+        attachListeners: function() {
+            var self = this;
 
             $(".controls").on("click", "button.stop", function(e) {
                 e.preventDefault();
                 Quagga.stop();
             });
+
+            $(".controls .reader-config-group").on("change", "input, select", function(e) {
+                e.preventDefault();
+                var $target = $(e.target),
+                    value = $target.attr("type") === "checkbox" ? $target.prop("checked") : $target.val(),
+                    name = $target.attr("name"),
+                    state = self._convertNameToState(name);
+
+                console.log("Value of "+ state + " changed to " + value);
+                self.setState(state, value);
+            });
         },
-        detachListeners : function() {
-            $(".controls .reader-group").off("change", "input");
+        _accessByPath: function(obj, path, val) {
+            var parts = path.split('.'),
+                depth = parts.length,
+                setter = (typeof val !== "undefined") ? true : false;
+
+            return parts.reduce(function(o, key, i) {
+                if (setter && (i + 1) === depth) {
+                    o[key] = val;
+                }
+                return key in o ? o[key] : {};
+            }, obj);
+        },
+        _convertNameToState: function(name) {
+            return name.replace("_", ".").split("-").reduce(function(result, value) {
+                return result + value.charAt(0).toUpperCase() + value.substring(1);
+            });
+        },
+        detachListeners: function() {
             $(".controls").off("click", "button.stop");
+            $(".controls .reader-config-group").off("change", "input, select");
+        },
+        setState: function(path, value) {
+            var self = this;
+
+            if (typeof self._accessByPath(self.inputMapper, path) === "function") {
+                value = self._accessByPath(self.inputMapper, path)(value);
+            }
+
+            self._accessByPath(self.state, path, value);
+
+            console.log(JSON.stringify(self.state));
+            App.detachListeners();
+            Quagga.stop();
+            App.init();
+        },
+        inputMapper: {
+            inputStream: {
+                constraints: function(value){
+                    var values = value.split('x');
+                    return {
+                        width: parseInt(values[0]),
+                        height: parseInt(values[1]),
+                        facing: "environment"
+                    }
+                }
+            },
+            numOfWorkers: function(value) {
+                return parseInt(value);
+            },
+            decoder: {
+                readers: function(value) {
+                    return [value + "_reader"];
+                }
+            }
+        },
+        state: {
+            inputStream: {
+                type : "LiveStream",
+                constraints: {
+                    width: 640,
+                    height: 480,
+                    facing: "environment" // or user
+                }
+            },
+            locator: {
+                patchSize: "medium",
+                halfSample: true
+            },
+            numOfWorkers: 4,
+            decoder: {
+                readers : ["code_128_reader"]
+            },
+            locate: true
         },
         lastResult : null
     };

example/static_images.html

@@ -29,16 +29,20 @@
             <strong>Code128</strong> and <strong>EAN</strong> encoded barcodes.
         </p>
       <div class="controls">
+          <fieldset class="input-group">
               <button class="next">Next</button>
-        <fieldset class="reader-group">
-            <label>Codabar</label>
-            <input type="radio" name="reader" value="codabar" checked />
-            <label>Code39</label>
-            <input type="radio" name="reader" value="code_39" />
-            <label>Code128</label>
-            <input type="radio" name="reader" value="code_128" />
-            <label>EAN</label>
-            <input type="radio" name="reader" value="ean" />
+          </fieldset>
+          <fieldset class="reader-config-group">
+              <span>Barcode-Type</span>
+              <select name="decoder_readers;input-stream_src">
+                  <option value="code_128" selected="selected">Code 128</option>
+                  <option value="code_39">Code 39</option>
+                  <option value="ean">EAN</option>
+                  <option value="ean_8">EAN-8</option>
+                  <option value="upc">UPC</option>
+                  <option value="upc_e">UPC-E</option>
+                  <option value="codabar">Codabar</option>
+              </select>
           </fieldset>
       </div>
       <div id="result_strip">

example/static_images.js

@@ -1,41 +1,95 @@
 $(function() {
     var App = {
         init: function() {
-            Quagga.init({
-                inputStream: { name: "Test",
-                   type: "ImageStream",
-                   src: "../test/fixtures/" + App.config.reader + "/",
-                   length: App.config.length
-                },
-                decoder : {
-                    readers : [App.config.reader + "_reader"]
-                }
-            }, function() {
+            Quagga.init(this.state, function() {
                 App.attachListeners();
                 Quagga.start();
             });
         },
         config: {
-            reader: "codabar",
+            reader: "code_128",
             length: 10
         },
         attachListeners: function() {
+            var self = this;
+
             $(".controls").on("click", "button.next", function(e) {
                 e.preventDefault();
                 Quagga.start();
             });
 
-            $(".controls .reader-group").on("change", "input", function(e) {
+            $(".controls .reader-config-group").on("change", "input, select", function(e) {
                 e.preventDefault();
-                App.detachListeners();
-                Quagga.stop();
-                App.config.reader = e.target.value;
-                App.init();
+                var $target = $(e.target),
+                    value = $target.attr("type") === "checkbox" ? $target.prop("checked") : $target.val(),
+                    name = $target.attr("name"),
+                    states = self._convertNameToStates(name);
+
+                console.log("Value of "+ states + " changed to " + value);
+                self.setState(states, value);
             });
         },
         detachListeners: function() {
             $(".controls").off("click", "button.next");
-            $(".controls .reader-group").off("change", "input");
+            $(".controls .reader-config-group").off("change", "input, select");
+        },
+        _accessByPath: function(obj, path, val) {
+            var parts = path.split('.'),
+                depth = parts.length,
+                setter = (typeof val !== "undefined") ? true : false;
+
+            return parts.reduce(function(o, key, i) {
+                if (setter && (i + 1) === depth) {
+                    o[key] = val;
+                }
+                return key in o ? o[key] : {};
+            }, obj);
+        },
+        _convertNameToStates: function(names) {
+            return names.split(";").map(this._convertNameToState.bind(this));
+        },
+        _convertNameToState: function(name) {
+            return name.replace("_", ".").split("-").reduce(function(result, value) {
+                return result + value.charAt(0).toUpperCase() + value.substring(1);
+            });
+        },
+        setState: function(paths, value) {
+            var self = this;
+
+            paths.forEach(function(path) {
+                var mappedValue;
+                if (typeof self._accessByPath(self.inputMapper, path) === "function") {
+                    mappedValue = self._accessByPath(self.inputMapper, path)(value);
+                }
+                self._accessByPath(self.state, path, mappedValue);
+            });
+
+            console.log(JSON.stringify(self.state));
+            App.detachListeners();
+            Quagga.stop();
+            App.init();
+        },
+        inputMapper: {
+            decoder: {
+                readers: function(value) {
+                    return [value + "_reader"];
+                }
+            },
+            inputStream: {
+                src: function(value) {
+                    return "../test/fixtures/" + value + "/"
+                }
+            }
+        },
+        state: {
+            inputStream: { name: "Test",
+                type: "ImageStream",
+                src: "../test/fixtures/code_128/",
+                length: 10
+            },
+            decoder : {
+                readers : ["code_128_reader"]
+            }
         }
     };
     

package.json

@@ -1,6 +1,6 @@
 {
   "name": "quagga",
-  "version": "0.5.4",
+  "version": "0.6.0",
   "description": "An advanced barcode-scanner written in JavaScript",
   "main": "dist/quagga.js",
   "devDependencies": {

src/barcode_decoder.js

@@ -1,14 +1,36 @@
 /* jshint undef: true, unused: true, browser:true, devel: true */
 /* global define */
 
-define(["bresenham", "image_debug", 'code_128_reader', 'ean_reader', 'code_39_reader', 'codabar_reader'], function(Bresenham, ImageDebug, Code128Reader, EANReader, Code39Reader, CodabarReader) {
+define([
+    "bresenham",
+    "image_debug",
+    'code_128_reader',
+    'ean_reader',
+    'code_39_reader',
+    'codabar_reader',
+    'upc_reader',
+    'ean_8_reader',
+    'upc_e_reader'
+], function(
+    Bresenham,
+    ImageDebug,
+    Code128Reader,
+    EANReader,
+    Code39Reader,
+    CodabarReader,
+    UPCReader,
+    EAN8Reader,
+    UPCEReader) {
     "use strict";
     
     var readers = {
         code_128_reader: Code128Reader,
         ean_reader: EANReader,
+        ean_8_reader: EAN8Reader,
         code_39_reader: Code39Reader,
-        codabar_reader: CodabarReader
+        codabar_reader: CodabarReader,
+        upc_reader: UPCReader,
+        upc_e_reader: UPCEReader
     };
     var BarcodeDecoder = {
         create : function(config, inputImageWrapper) {
@@ -96,18 +118,25 @@ define(["bresenham", "image_debug", 'code_128_reader', 'ean_reader', 'code_39_re
              * @param {Number} angle 
              */
             function getExtendedLine(line, angle, ext) {
+                function extendLine(amount) {
                     var extension = {
-                        y : ext * Math.sin(angle),
-                        x : ext * Math.cos(angle)
+                        y : amount * Math.sin(angle),
+                        x : amount * Math.cos(angle)
                     };
 
                     line[0].y -= extension.y;
                     line[0].x -= extension.x;
                     line[1].y += extension.y;
                     line[1].x += extension.x;
+                }
 
                 // check if inside image
-                if (!inputImageWrapper.inImageWithBorder(line[0], 0) || !inputImageWrapper.inImageWithBorder(line[1], 0)) {
+                extendLine(ext);
+                while (ext > 1 && !inputImageWrapper.inImageWithBorder(line[0], 0) || !inputImageWrapper.inImageWithBorder(line[1], 0)) {
+                    ext -= Math.floor(ext/2);
+                    extendLine(-ext);
+                }
+                if (ext <= 1) {
                     return null;
                 }
                 return line;
@@ -187,6 +216,12 @@ define(["bresenham", "image_debug", 'code_128_reader', 'ean_reader', 'code_39_re
                 return result;
             }
 
+            function getLineLength(line) {
+                return Math.sqrt(
+                    Math.pow(Math.abs(line[1].y - line[0].y), 2) +
+                    Math.pow(Math.abs(line[1].x - line[0].x), 2));
+            }
+
             /**
              * With the help of the configured readers (Code128 or EAN) this function tries to detect a 
              * valid barcode pattern within the given area.
@@ -197,15 +232,17 @@ define(["bresenham", "image_debug", 'code_128_reader', 'ean_reader', 'code_39_re
                 var line,
                     lineAngle,
                     ctx = _canvas.ctx.overlay,
-                    result;
+                    result,
+                    lineLength;
 
                 if (config.drawBoundingBox && ctx) {
                     ImageDebug.drawPath(box, {x: 0, y: 1}, ctx, {color: "blue", lineWidth: 2});
                 }
 
                 line = getLine(box);
+                lineLength = getLineLength(line);
                 lineAngle = Math.atan2(line[1].y - line[0].y, line[1].x - line[0].x);
-                line = getExtendedLine(line, lineAngle, 10);
+                line = getExtendedLine(line, lineAngle, Math.floor(lineLength*0.1));
                 if(line === null){
                     return null;
                 }

src/bresenham.js

@@ -107,23 +107,23 @@ define(function() {
             extrema = [],
             currentDir,
             dir,
-            threshold = (max - min) / 8,
+            threshold = (max - min) / 12,
             rThreshold = -threshold,
             i,
             j;
 
         // 1. find extrema
-        currentDir = line[0] > center ? Slope.DIR.DOWN : Slope.DIR.UP;
+        currentDir = line[0] > center ? Slope.DIR.UP : Slope.DIR.DOWN;
         extrema.push({
             pos : 0,
             val : line[0]
         });
         for ( i = 0; i < line.length - 1; i++) {
             slope = (line[i + 1] - line[i]);
-            if (slope < rThreshold) {
-                dir = Slope.DIR.UP;
-            } else if (slope > threshold) {
+            if (slope < rThreshold && line[i + 1] < (center*1.5)) {
                 dir = Slope.DIR.DOWN;
+            } else if (slope > threshold && line[i + 1] > (center*0.5)) {
+                dir = Slope.DIR.UP;
             } else {
                 dir = currentDir;
             }

src/camera_access.js

@@ -3,7 +3,8 @@
 
 define(["html_utils"], function(HtmlUtils) {
     "use strict";
-    var streamRef;
+    var streamRef,
+        loadedDataHandler;
     
     /**
      * Wraps browser-specific getUserMedia
@@ -19,17 +20,7 @@ define(["html_utils"], function(HtmlUtils) {
         }, failure);
     }
 
-    /**
-     * Tries to attach the camera-stream to a given video-element
-     * and calls the callback function when the content is ready
-     * @param {Object} constraints
-     * @param {Object} video
-     * @param {Object} callback
-     */
-    function initCamera(constraints, video, callback) {
-        getUserMedia(constraints, function(src) {
-            video.src = src;
-            video.addEventListener('loadeddata', function() {
+    function loadedData(video, callback) {
         var attempts = 10;
 
         function checkVideo() {
@@ -45,9 +36,24 @@ define(["html_utils"], function(HtmlUtils) {
             }
             attempts--;
         }
-
         checkVideo();
-            }, false);
+    }
+
+    /**
+     * Tries to attach the camera-stream to a given video-element
+     * and calls the callback function when the content is ready
+     * @param {Object} constraints
+     * @param {Object} video
+     * @param {Object} callback
+     */
+    function initCamera(constraints, video, callback) {
+        getUserMedia(constraints, function(src) {
+            video.src = src;
+            if (loadedDataHandler) {
+                video.removeEventListener("loadeddata", loadedDataHandler, false);
+            }
+            loadedDataHandler = loadedData.bind(null, video, callback);
+            video.addEventListener('loadeddata', loadedDataHandler, false);
             video.play();
         }, function(e) {
             console.log(e);

src/ean_8_reader.js

@@ -0,0 +1,45 @@
+/* jshint undef: true, unused: true, browser:true, devel: true */
+/* global define */
+
+define(
+    [
+        "./ean_reader"
+    ],
+    function(EANReader) {
+        "use strict";
+
+        function EAN8Reader() {
+            EANReader.call(this);
+        }
+
+        EAN8Reader.prototype = Object.create(EANReader.prototype);
+        EAN8Reader.prototype.constructor = EAN8Reader;
+
+        EAN8Reader.prototype._decodePayload = function(code, result, decodedCodes) {
+            var i,
+                self = this;
+
+            for ( i = 0; i < 4; i++) {
+                code = self._decodeCode(code.end);
+                result.push(code.code);
+                decodedCodes.push(code);
+            }
+
+            code = self._findPattern(self.MIDDLE_PATTERN, code.end, true);
+            if (code === null) {
+                return null;
+            }
+            decodedCodes.push(code);
+
+            for ( i = 0; i < 4; i++) {
+                code = self._decodeCode(code.end, self.CODE_G_START);
+                decodedCodes.push(code);
+                result.push(code.code);
+            }
+
+            return code;
+        };
+
+        return (EAN8Reader);
+    }
+);

src/ean_reader.js

@@ -167,23 +167,50 @@ define(
             throw BarcodeReader.PatternNotFoundException;
         };
 
-        EANReader.prototype._decode = function() {
-            var startInfo,
-                self = this,
-                code = null, 
-                result = [],
-                i,
-                codeFrequency = 0x0,
-                decodedCodes = [];
+        EANReader.prototype._findStart = function() {
+            var self = this,
+                leadingWhitespaceStart,
+                offset = self._nextSet(self._row),
+                startInfo;
 
-            try {
-                startInfo = self._findPattern(self.START_PATTERN);
-                code = {
-                    code : startInfo.code,
-                    start : startInfo.start,
-                    end : startInfo.end
+            while(!startInfo) {
+                startInfo = self._findPattern(self.START_PATTERN, offset);
+                leadingWhitespaceStart = startInfo.start - (startInfo.end - startInfo.start);
+                if (leadingWhitespaceStart >= 0) {
+                    if (self._matchRange(leadingWhitespaceStart, startInfo.start, 0)) {
+                        return startInfo;
+                    }
+                }
+                offset = startInfo.end;
+                startInfo = null;
+            }
         };
-                decodedCodes.push(code);
+
+        EANReader.prototype._verifyTrailingWhitespace = function(endInfo) {
+            var self = this,
+                trailingWhitespaceEnd;
+
+            trailingWhitespaceEnd = endInfo.end + (endInfo.end - endInfo.start);
+            if (trailingWhitespaceEnd < self._row.length) {
+                if (self._matchRange(endInfo.end, trailingWhitespaceEnd, 0)) {
+                    return endInfo;
+                }
+            }
+            return null;
+        };
+
+        EANReader.prototype._findEnd = function(offset, isWhite) {
+            var self = this,
+                endInfo = self._findPattern(self.STOP_PATTERN, offset, isWhite, false);
+
+            return self._verifyTrailingWhitespace(endInfo);
+        };
+
+        EANReader.prototype._decodePayload = function(code, result, decodedCodes) {
+            var i,
+                self = this,
+                codeFrequency = 0x0;
+
             for ( i = 0; i < 6; i++) {
                 code = self._decodeCode(code.end);
                 if (code.code >= self.CODE_G_START) {
@@ -203,7 +230,7 @@ define(
                 }
             }
 
-                code = self._findPattern(self.MIDDLE_PATTERN, code.end, true);
+            code = self._findPattern(self.MIDDLE_PATTERN, code.end, true, false);
             if (code === null) {
                 return null;
             }
@@ -215,7 +242,30 @@ define(
                 result.push(code.code);
             }
 
-                code = self._findPattern(self.STOP_PATTERN, code.end);
+            return code;
+        };
+
+        EANReader.prototype._decode = function() {
+            var startInfo,
+                self = this,
+                code = null, 
+                result = [],
+                decodedCodes = [];
+
+            try {
+                startInfo = self._findStart();
+                code = {
+                    code : startInfo.code,
+                    start : startInfo.start,
+                    end : startInfo.end
+                };
+                decodedCodes.push(code);
+                code = self._decodePayload(code, result, decodedCodes);
+                code = self._findEnd(code.end, false);
+                if (!code){
+                    return null;
+                }
+
                 decodedCodes.push(code);
 
                 // Checksum

src/input_stream.js

@@ -68,6 +68,17 @@ define(["image_loader"], function(ImageLoader) {
             }
         };
 
+        that.clearEventHandlers = function() {
+            _eventNames.forEach(function(eventName) {
+                var handlers = _eventHandlers[eventName];
+                if (handlers && handlers.length > 0) {
+                    handlers.forEach(function(handler) {
+                        video.removeEventListener(eventName, handler);
+                    });
+                }
+            });
+        };
+
         that.trigger = function(eventName, args) {
             var j,
                 handlers = _eventHandlers[eventName];

src/quagga.js

@@ -407,8 +407,14 @@ function(Code128Reader,
         },
         stop : function() {
             _stopped = true;
+            _workerPool.forEach(function(workerThread) {
+                workerThread.worker.terminate();
+                console.log("Worker terminated!");
+            });
+            _workerPool.length = 0;
             if (_config.inputStream.type === "LiveStream") {
                 CameraAccess.release();
+                _inputStream.clearEventHandlers();
             }
         },
         pause: function() {

src/upc_e_reader.js

@@ -0,0 +1,109 @@
+/* jshint undef: true, unused: true, browser:true, devel: true */
+/* global define */
+
+define(
+    [
+        "./ean_reader"
+    ],
+    function(EANReader) {
+        "use strict";
+
+        function UPCEReader() {
+            EANReader.call(this);
+        }
+
+        var properties = {
+            CODE_FREQUENCY : {value: [
+                [ 56, 52, 50, 49, 44, 38, 35, 42, 41, 37 ],
+                [7, 11, 13, 14, 19, 25, 28, 21, 22, 26]]},
+            STOP_PATTERN: { value: [1 / 6 * 7, 1 / 6 * 7, 1 / 6 * 7, 1 / 6 * 7, 1 / 6 * 7, 1 / 6 * 7]}
+        };
+
+        UPCEReader.prototype = Object.create(EANReader.prototype, properties);
+        UPCEReader.prototype.constructor = UPCEReader;
+
+        UPCEReader.prototype._decodePayload = function(code, result, decodedCodes) {
+            var i,
+                self = this,
+                codeFrequency = 0x0;
+
+            for ( i = 0; i < 6; i++) {
+                code = self._decodeCode(code.end);
+                if (code.code >= self.CODE_G_START) {
+                    code.code = code.code - self.CODE_G_START;
+                    codeFrequency |= 1 << (5 - i);
+                } else {
+                    codeFrequency |= 0 << (5 - i);
+                }
+                result.push(code.code);
+                decodedCodes.push(code);
+            }
+            self._determineParity(codeFrequency, result);
+
+            return code;
+        };
+
+        UPCEReader.prototype._determineParity = function(codeFrequency, result) {
+            var self =this,
+                i,
+                nrSystem;
+
+            for (nrSystem = 0; nrSystem < self.CODE_FREQUENCY.length; nrSystem++){
+                for ( i = 0; i < self.CODE_FREQUENCY[nrSystem].length; i++) {
+                    if (codeFrequency === self.CODE_FREQUENCY[nrSystem][i]) {
+                        result.unshift(nrSystem);
+                        result.push(i);
+                        return;
+                    }
+                }
+            }
+        };
+
+        UPCEReader.prototype._convertToUPCA = function(result) {
+            var upca = [result[0]],
+                lastDigit = result[result.length - 2];
+
+            if (lastDigit <= 2) {
+                upca = upca.concat(result.slice(1, 3))
+                    .concat([lastDigit, 0, 0, 0, 0])
+                    .concat(result.slice(3, 6));
+            } else if (lastDigit === 3) {
+                upca = upca.concat(result.slice(1, 4))
+                    .concat([0 ,0, 0, 0, 0])
+                    .concat(result.slice(4,6));
+            } else if (lastDigit === 4) {
+                upca = upca.concat(result.slice(1, 5))
+                    .concat([0, 0, 0, 0, 0, result[5]]);
+            } else {
+                upca = upca.concat(result.slice(1, 6))
+                    .concat([0, 0, 0, 0, lastDigit]);
+            }
+
+            upca.push(result[result.length - 1]);
+            return upca;
+        };
+
+        UPCEReader.prototype._checksum = function(result) {
+            return EANReader.prototype._checksum.call(this, this._convertToUPCA(result));
+        };
+
+        UPCEReader.prototype._findEnd = function(offset, isWhite) {
+            isWhite = true;
+            return EANReader.prototype._findEnd.call(this, offset, isWhite);
+        };
+
+        UPCEReader.prototype._verifyTrailingWhitespace = function(endInfo) {
+            var self = this,
+                trailingWhitespaceEnd;
+
+            trailingWhitespaceEnd = endInfo.end + ((endInfo.end - endInfo.start)/2);
+            if (trailingWhitespaceEnd < self._row.length) {
+                if (self._matchRange(endInfo.end, trailingWhitespaceEnd, 0)) {
+                    return endInfo;
+                }
+            }
+        };
+
+        return (UPCEReader);
+    }
+);

src/upc_reader.js

@@ -0,0 +1,31 @@
+/* jshint undef: true, unused: true, browser:true, devel: true */
+/* global define */
+
+define(
+    [
+        "./ean_reader"
+    ],
+    function(EANReader) {
+        "use strict";
+
+        function UPCReader() {
+            EANReader.call(this);
+        }
+
+        UPCReader.prototype = Object.create(EANReader.prototype);
+        UPCReader.prototype.constructor = UPCReader;
+
+        UPCReader.prototype._decode = function() {
+            var result = EANReader.prototype._decode.call(this);
+
+            if (result && result.code && result.code.length === 13 && result.code.charAt(0) === "0") {
+
+                result.code = result.code.substring(1);
+                return result;
+            }
+            return null;
+        };
+
+        return (UPCReader);
+    }
+);