Experimenting with detecting the whole area

src/common/geometric.js

@@ -1,3 +1,6 @@
+const vec2 = {
+    clone: require('gl-vec2/clone')
+};
 
 export function getCenterLineFromBox(box) {
     return [{
@@ -41,3 +44,10 @@ export function getExtendedLine(inputImageWrapper, line, angle, ext) {
     }
     return line;
 }
+
+export function getPointOnLine(line, distance, angle) {
+    const x = distance * Math.cos(angle) + line[0].x,
+        y = distance * Math.sin(angle) + line[0].y;
+
+    return vec2.clone([x, y]);
+}

src/detector/pdf_147_detector.js

@@ -2,7 +2,8 @@ import {
     getCenterLineFromBox as getLine,
     getLineLength,
     getLineAngle,
-    getExtendedLine
+    getExtendedLine,
+    getPointOnLine
 } from '../common/geometric';
 import ImageDebug from '../common/image_debug';
 import Bresenham from '../decoder/bresenham';
@@ -11,29 +12,52 @@ import {findPattern} from '../reader/common';
 const vec2 = {
     clone: require('gl-vec2/clone'),
     dot: require('gl-vec2/dot')
-}
+};
 
 const START_PATTERN = [8, 1, 1, 1, 1, 1, 1, 3],
     STOP_PATTERN = [7, 1, 1, 3, 1, 1, 1, 2, 1],
-    MODULO = START_PATTERN.reduce((sum, i) => (sum + i),0);
+    MODULO = START_PATTERN.reduce((sum, i) => (sum + i), 0);
 
-export default function detect(inputImageWrapper, box, ctx) {
-    let line = getLine(box),
-        lineLength = getLineLength(line),
-        lineAngle = getLineAngle(line),
-        extendedLine = getExtendedLine(inputImageWrapper, line, lineAngle, Math.floor(lineLength * 0.15)),
-        barcodeLine = Bresenham.getBarcodeLine(inputImageWrapper, extendedLine[0], extendedLine[1]);
+function findTopLeft(line, angle, inputImageWrapper, ctx) {
+    let barcodeLine,
+        match,
+        pos = [
+            vec2.clone([0, 0]),
+            vec2.clone([0, 0])
+        ],
+        xdir = Math.sin(angle),
+        ydir = Math.cos(angle);
 
-    if (ENV.development) {
-        if (ctx) {
-            ImageDebug.drawPath(extendedLine, {x: 'x', y: 'y'}, ctx, {color: 'red', lineWidth: 1});
-        }
+    do {
+        barcodeLine = Bresenham.getBarcodeLine(inputImageWrapper, line[0], line[1]);
+        if (ENV.development && ctx) {
+            ImageDebug.drawPath(line, {x: 'x', y: 'y'}, ctx, {color: 'red', lineWidth: 1});
         }
 
         Bresenham.toBinaryLine(barcodeLine);
+        match = findPattern(barcodeLine.line, START_PATTERN, {modulo: MODULO});
+        if (match) {
+            pos[0] = getPointOnLine(line, match.start, angle);
+            pos[1] = getPointOnLine(line, match.end, angle);
+            line[0].x += xdir*10;
+            line[0].y -= ydir*10;
+            line[1].x += xdir*10;
+            line[1].y -= ydir*10;
+        }
+        ImageDebug.drawVertices(pos, {x: 0, y: 1}, ctx, {color: 'blue', lineWidth: 1});
+    } while (match);
+
+    return pos;
+}
+
+export default function detect(inputImageWrapper, box, ctx) {
+    let line = getLine(box),
+        lineLength = getLineLength(line),
+        lineAngle = getLineAngle(line),
+        extendedLine = getExtendedLine(inputImageWrapper, line, lineAngle, Math.floor(lineLength * 0.15));
 
-    const match = findPattern(barcodeLine.line, START_PATTERN, {modulo: MODULO});
-    console.log(match);
+    var topLeft = findTopLeft(extendedLine, lineAngle, inputImageWrapper, ctx);
+    console.log(topLeft);
 
     return [
         vec2.clone([199, 84]),
@@ -44,5 +68,5 @@ export default function detect(inputImageWrapper, box, ctx) {
         vec2.clone([310, 295]),
         vec2.clone([554, 83]),
         vec2.clone([580, 277])
-    ]
+    ];
 };

src/reader/common.js

@@ -60,8 +60,8 @@ export function findPattern(row, pattern, {
         offset,
         isWhite=false,
         tryHarder=true,
-        epsilon=0.5,
-        maxSingleError=0.5,
+        epsilon=0.8,
+        maxSingleError=0.8,
         modulo}) {
     var counter = [],
         i,