Improving EAN-Reader, Barcode-Line extension, ToBinaryLine

dist/quagga.js

@@ -1240,6 +1240,39 @@ define(
             throw BarcodeReader.PatternNotFoundException;
         };
 
+        EANReader.prototype._findStart = function() {
+            var self = this,
+                leadingWhitespaceStart,
+                offset = self._nextSet(self._row),
+                startInfo;
+
+            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;
+            }
+        };
+
+        EANReader.prototype._findEnd = function(offset) {
+            var self = this,
+                trailingWhitespaceEnd,
+                endInfo = self._findPattern(self.STOP_PATTERN, offset);
+
+            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._decode = function() {
             var startInfo,
                 self = this,
@@ -1250,7 +1283,7 @@ define(
                 decodedCodes = [];
 
             try {
-                startInfo = self._findPattern(self.START_PATTERN);
+                startInfo = self._findStart();
                 code = {
                     code : startInfo.code,
                     start : startInfo.start,
@@ -1288,7 +1321,11 @@ define(
                     result.push(code.code);
                 }
 
-                code = self._findPattern(self.STOP_PATTERN, code.end);
+                code = self._findEnd(code.end);
+                if (code === null){
+                    return null;
+                }
+
                 decodedCodes.push(code);
 
                 // Checksum
@@ -6384,23 +6421,23 @@ 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) {
+            if (slope < rThreshold && line[i + 1] < (center*1.5)) {
-                dir = Slope.DIR.UP;
-            } else if (slope > threshold) {
                 dir = Slope.DIR.DOWN;
+            } else if (slope > threshold && line[i + 1] > (center*0.5)) {
+                dir = Slope.DIR.UP;
             } else {
                 dir = currentDir;
             }
@@ -7090,18 +7127,25 @@ 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),
+                        y : amount * Math.sin(angle),
-                        x : ext * Math.cos(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 +7225,12 @@ 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 +7241,17 @@ 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*0.07));
                 if(line === null){
                     return null;
                 }
@@ -7402,7 +7454,7 @@ define('config',[],function(){
       debug: false,
       controls: false,
       locate: true,
-      numOfWorkers: 4,
+      numOfWorkers: 0,
       visual: {
         show: true
       },

example/file_input.html

@@ -42,9 +42,9 @@
             <label>
                 <span>Barcode-Type</span>
                 <select name="decoder_readers">
-                    <option value="code_128" selected="selected">Code 128</option>
+                    <option value="code_128">Code 128</option>
                     <option value="code_39">Code 39</option>
-                    <option value="ean">EAN</option>
+                    <option value="ean" selected="selected">EAN</option>
                     <option value="codabar">Codabar</option>
                 </select>
             </label>
@@ -52,8 +52,8 @@
                 <span>Resolution (long side)</span>
                 <select name="input-stream_size">
                     <option value="320">320px</option>
-                    <option value="640">640px</option>
+                    <option selected="selected" value="640">640px</option>
-                    <option selected="selected" value="800">800px</option>
+                    <option value="800">800px</option>
                     <option value="1280">1280px</option>
                     <option value="1600">1600px</option>
                     <option value="1920">1920px</option>
@@ -64,8 +64,8 @@
                 <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="medium">medium</option>
-                    <option value="large">large</option>
+                    <option selected="selected" value="large">large</option>
                     <option value="x-large">x-large</option>
                 </select>
             </label>
@@ -76,8 +76,8 @@
             <label>
                 <span>Workers</span>
                 <select name="numOfWorkers">
-                    <option value="0">0</option>
+                    <option selected="selected" value="0">0</option>
-                    <option value="1" selected="selected">1</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

@@ -92,15 +92,17 @@ $(function() {
         },
         state: {
             inputStream: {
-                size: 800
+                size: 640
             },
             locator: {
-                patchSize: "medium",
+                patchSize: "large",
                 halfSample: false
             },
-            numOfWorkers: 1,
+            numOfWorkers: 0,
             decoder: {
-                readers: ["code_128_reader"]
+                readers: ["ean_reader"],
+                showFrequency: true,
+                showPattern: true
             },
             locate: true,
             src: null

example/static_images.html

@@ -32,13 +32,13 @@
         <button class="next">Next</button>
         <fieldset class="reader-group">
             <label>Codabar</label>
-            <input type="radio" name="reader" value="codabar" checked />
+            <input type="radio" name="reader" value="codabar" />
             <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" />
+            <input type="radio" name="reader" value="ean" checked />
         </fieldset>
       </div>
       <div id="result_strip">

example/static_images.js

@@ -16,7 +16,7 @@ $(function() {
             });
         },
         config: {
-            reader: "codabar",
+            reader: "ean",
             length: 10
         },
         attachListeners: function() {

src/barcode_decoder.js

@@ -96,18 +96,25 @@ 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),
+                        y : amount * Math.sin(angle),
-                        x : ext * Math.cos(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 +194,12 @@ 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 +210,17 @@ 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*0.07));
                 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) {
+            if (slope < rThreshold && line[i + 1] < (center*1.5)) {
-                dir = Slope.DIR.UP;
-            } else if (slope > threshold) {
                 dir = Slope.DIR.DOWN;
+            } else if (slope > threshold && line[i + 1] > (center*0.5)) {
+                dir = Slope.DIR.UP;
             } else {
                 dir = currentDir;
             }

src/ean_reader.js

@@ -167,6 +167,39 @@ define(
             throw BarcodeReader.PatternNotFoundException;
         };
 
+        EANReader.prototype._findStart = function() {
+            var self = this,
+                leadingWhitespaceStart,
+                offset = self._nextSet(self._row),
+                startInfo;
+
+            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;
+            }
+        };
+
+        EANReader.prototype._findEnd = function(offset) {
+            var self = this,
+                trailingWhitespaceEnd,
+                endInfo = self._findPattern(self.STOP_PATTERN, offset);
+
+            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._decode = function() {
             var startInfo,
                 self = this,
@@ -177,7 +210,7 @@ define(
                 decodedCodes = [];
 
             try {
-                startInfo = self._findPattern(self.START_PATTERN);
+                startInfo = self._findStart();
                 code = {
                     code : startInfo.code,
                     start : startInfo.start,
@@ -215,7 +248,11 @@ define(
                     result.push(code.code);
                 }
 
-                code = self._findPattern(self.STOP_PATTERN, code.end);
+                code = self._findEnd(code.end);
+                if (code === null){
+                    return null;
+                }
+
                 decodedCodes.push(code);
 
                 // Checksum