Add option to disable inverting (cozmo#78)

* Add option to disable inverting
jeongjaehong · Aug 15, 2018 · 807b073 · 807b073
1 parent c8d0ed0
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diff --git a/README.md b/README.md
@@ -46,10 +46,10 @@ If you want to use jsQR to scan a webcam stream you'll need to extract the [`Ima
 
 ## Usage
 
-jsQR exports a method that takes in 3 arguments representing the image data you wish to decode.
+jsQR exports a method that takes in 3 arguments representing the image data you wish to decode. Additionally can take an options object to further configure scanning behavior.
 
 ```javascript
-const code = jsQR(imageData, width, height);
+const code = jsQR(imageData, width, height, options?);
 
 if (code) {
   console.log("Found QR code", code);
@@ -61,7 +61,9 @@ if (code) {
 As such the length of this array should be `4 * width * height`.
 This data is in the same form as the [`ImageData`](https://developer.mozilla.org/en-US/docs/Web/API/ImageData) interface, and it's also [commonly](https://www.npmjs.com/package/jpeg-js#decoding-jpegs) [returned](https://github.com/lukeapage/pngjs/blob/master/README.md#property-data) by node modules for reading images.
 - `width` - The width of the image you wish to decode.
-- `height` The height of the image you wish to decode.
+- `height` - The height of the image you wish to decode.
+- `options` (optional) - Additional options.
+  - `inversionAttempts` - (`attemptBoth` (default), `dontInvert`, `onlyInvert`, or `invertFirst`) - Should jsQR attempt to invert the image to find QR codes with white modules on black backgrounds instead of the black modules on white background. This option defaults to `attemptBoth` for backwards compatibility but causes a ~50% performance hit, and will probably be default to `dontInvert` in future versions.
 
 ### Return value
 If a QR is able to be decoded the library will return an object with the following keys.

diff --git a/dist/BitMatrix.d.ts b/dist/BitMatrix.d.ts
@@ -7,5 +7,4 @@ export declare class BitMatrix {
     get(x: number, y: number): boolean;
     set(x: number, y: number, v: boolean): void;
     setRegion(left: number, top: number, width: number, height: number, v: boolean): void;
-    getInverted(): BitMatrix;
 }
diff --git a/dist/binarizer/index.d.ts b/dist/binarizer/index.d.ts
@@ -1,2 +1,8 @@
 import { BitMatrix } from "../BitMatrix";
-export declare function binarize(data: Uint8ClampedArray, width: number, height: number): BitMatrix;
+export declare function binarize(data: Uint8ClampedArray, width: number, height: number, returnInverted: boolean): {
+    binarized: BitMatrix;
+    inverted: BitMatrix;
+} | {
+    binarized: BitMatrix;
+    inverted?: undefined;
+};
diff --git a/dist/index.d.ts b/dist/index.d.ts
@@ -15,5 +15,8 @@ export interface QRCode {
         bottomRightAlignmentPattern?: Point;
     };
 }
-declare function jsQR(data: Uint8ClampedArray, width: number, height: number): QRCode | null;
+export interface Options {
+    inversionAttempts?: "dontInvert" | "onlyInvert" | "attemptBoth" | "invertFirst";
+}
+declare function jsQR(data: Uint8ClampedArray, width: number, height: number, providedOptions?: Options): QRCode | null;
 export default jsQR;
diff --git a/dist/jsQR.js b/dist/jsQR.js
@@ -105,9 +105,6 @@ var BitMatrix = /** @class */ (function () {
             }
         }
     };
-    BitMatrix.prototype.getInverted = function () {
-        return new BitMatrix(this.data.map(function (d) { return d === 0 ? 1 : 0; }), this.width);
-    };
     return BitMatrix;
 }());
 exports.BitMatrix = BitMatrix;
@@ -357,11 +354,21 @@ function scan(matrix) {
         },
     };
 }
-function jsQR(data, width, height) {
-    var binarized = binarizer_1.binarize(data, width, height);
-    var result = scan(binarized);
-    if (!result) {
-        result = scan(binarized.getInverted());
+var defaultOptions = {
+    inversionAttempts: "attemptBoth",
+};
+function jsQR(data, width, height, providedOptions) {
+    if (providedOptions === void 0) { providedOptions = {}; }
+    var options = defaultOptions;
+    Object.keys(options || {}).forEach(function (opt) {
+        options[opt] = providedOptions[opt] || options[opt];
+    });
+    var shouldInvert = options.inversionAttempts === "attemptBoth" || options.inversionAttempts === "invertFirst";
+    var tryInvertedFirst = options.inversionAttempts === "onlyInvert" || options.inversionAttempts === "invertFirst";
+    var _a = binarizer_1.binarize(data, width, height, shouldInvert), binarized = _a.binarized, inverted = _a.inverted;
+    var result = scan(tryInvertedFirst ? inverted : binarized);
+    if (!result && (options.inversionAttempts === "attemptBoth" || options.inversionAttempts === "invertFirst")) {
+        result = scan(tryInvertedFirst ? binarized : inverted);
     }
     return result;
 }
@@ -396,7 +403,7 @@ var Matrix = /** @class */ (function () {
     };
     return Matrix;
 }());
-function binarize(data, width, height) {
+function binarize(data, width, height, returnInverted) {
     if (data.length !== width * height * 4) {
         throw new Error("Malformed data passed to binarizer.");
     }
@@ -453,6 +460,10 @@ function binarize(data, width, height) {
         }
     }
     var binarized = BitMatrix_1.BitMatrix.createEmpty(width, height);
+    var inverted = null;
+    if (returnInverted) {
+        inverted = BitMatrix_1.BitMatrix.createEmpty(width, height);
+    }
     for (var verticalRegion = 0; verticalRegion < verticalRegionCount; verticalRegion++) {
         for (var hortizontalRegion = 0; hortizontalRegion < horizontalRegionCount; hortizontalRegion++) {
             var left = numBetween(hortizontalRegion, 2, horizontalRegionCount - 3);
@@ -464,15 +475,23 @@ function binarize(data, width, height) {
                 }
             }
             var threshold = sum / 25;
-            for (var x = 0; x < REGION_SIZE; x++) {
-                for (var y = 0; y < REGION_SIZE; y++) {
-                    var lum = greyscalePixels.get(hortizontalRegion * REGION_SIZE + x, verticalRegion * REGION_SIZE + y);
-                    binarized.set(hortizontalRegion * REGION_SIZE + x, verticalRegion * REGION_SIZE + y, lum <= threshold);
+            for (var xRegion = 0; xRegion < REGION_SIZE; xRegion++) {
+                for (var yRegion = 0; yRegion < REGION_SIZE; yRegion++) {
+                    var x = hortizontalRegion * REGION_SIZE + xRegion;
+                    var y = verticalRegion * REGION_SIZE + yRegion;
+                    var lum = greyscalePixels.get(x, y);
+                    binarized.set(x, y, lum <= threshold);
+                    if (returnInverted) {
+                        inverted.set(x, y, !(lum <= threshold));
+                    }
                 }
             }
         }
     }
-    return binarized;
+    if (returnInverted) {
+        return { binarized: binarized, inverted: inverted };
+    }
+    return { binarized: binarized };
 }
 exports.binarize = binarize;
 

diff --git a/docs/index.html b/docs/index.html
@@ -99,7 +99,9 @@ <h1>jsQR Demo</h1>
         canvasElement.width = video.videoWidth;
         canvas.drawImage(video, 0, 0, canvasElement.width, canvasElement.height);
         var imageData = canvas.getImageData(0, 0, canvasElement.width, canvasElement.height);
-        var code = jsQR(imageData.data, imageData.width, imageData.height);
+        var code = jsQR(imageData.data, imageData.width, imageData.height, {
+          inversionAttempts: "dontInvert",
+        });
         if (code) {
           drawLine(code.location.topLeftCorner, code.location.topRightCorner, "#FF3B58");
           drawLine(code.location.topRightCorner, code.location.bottomRightCorner, "#FF3B58");

diff --git a/docs/jsQR.js b/docs/jsQR.js
@@ -105,9 +105,6 @@ var BitMatrix = /** @class */ (function () {
             }
         }
     };
-    BitMatrix.prototype.getInverted = function () {
-        return new BitMatrix(this.data.map(function (d) { return d === 0 ? 1 : 0; }), this.width);
-    };
     return BitMatrix;
 }());
 exports.BitMatrix = BitMatrix;
@@ -357,11 +354,21 @@ function scan(matrix) {
         },
     };
 }
-function jsQR(data, width, height) {
-    var binarized = binarizer_1.binarize(data, width, height);
-    var result = scan(binarized);
-    if (!result) {
-        result = scan(binarized.getInverted());
+var defaultOptions = {
+    inversionAttempts: "attemptBoth",
+};
+function jsQR(data, width, height, providedOptions) {
+    if (providedOptions === void 0) { providedOptions = {}; }
+    var options = defaultOptions;
+    Object.keys(options || {}).forEach(function (opt) {
+        options[opt] = providedOptions[opt] || options[opt];
+    });
+    var shouldInvert = options.inversionAttempts === "attemptBoth" || options.inversionAttempts === "invertFirst";
+    var tryInvertedFirst = options.inversionAttempts === "onlyInvert" || options.inversionAttempts === "invertFirst";
+    var _a = binarizer_1.binarize(data, width, height, shouldInvert), binarized = _a.binarized, inverted = _a.inverted;
+    var result = scan(tryInvertedFirst ? inverted : binarized);
+    if (!result && (options.inversionAttempts === "attemptBoth" || options.inversionAttempts === "invertFirst")) {
+        result = scan(tryInvertedFirst ? binarized : inverted);
     }
     return result;
 }
@@ -396,7 +403,7 @@ var Matrix = /** @class */ (function () {
     };
     return Matrix;
 }());
-function binarize(data, width, height) {
+function binarize(data, width, height, returnInverted) {
     if (data.length !== width * height * 4) {
         throw new Error("Malformed data passed to binarizer.");
     }
@@ -453,6 +460,10 @@ function binarize(data, width, height) {
         }
     }
     var binarized = BitMatrix_1.BitMatrix.createEmpty(width, height);
+    var inverted = null;
+    if (returnInverted) {
+        inverted = BitMatrix_1.BitMatrix.createEmpty(width, height);
+    }
     for (var verticalRegion = 0; verticalRegion < verticalRegionCount; verticalRegion++) {
         for (var hortizontalRegion = 0; hortizontalRegion < horizontalRegionCount; hortizontalRegion++) {
             var left = numBetween(hortizontalRegion, 2, horizontalRegionCount - 3);
@@ -464,15 +475,23 @@ function binarize(data, width, height) {
                 }
             }
             var threshold = sum / 25;
-            for (var x = 0; x < REGION_SIZE; x++) {
-                for (var y = 0; y < REGION_SIZE; y++) {
-                    var lum = greyscalePixels.get(hortizontalRegion * REGION_SIZE + x, verticalRegion * REGION_SIZE + y);
-                    binarized.set(hortizontalRegion * REGION_SIZE + x, verticalRegion * REGION_SIZE + y, lum <= threshold);
+            for (var xRegion = 0; xRegion < REGION_SIZE; xRegion++) {
+                for (var yRegion = 0; yRegion < REGION_SIZE; yRegion++) {
+                    var x = hortizontalRegion * REGION_SIZE + xRegion;
+                    var y = verticalRegion * REGION_SIZE + yRegion;
+                    var lum = greyscalePixels.get(x, y);
+                    binarized.set(x, y, lum <= threshold);
+                    if (returnInverted) {
+                        inverted.set(x, y, !(lum <= threshold));
+                    }
                 }
             }
         }
     }
-    return binarized;
+    if (returnInverted) {
+        return { binarized: binarized, inverted: inverted };
+    }
+    return { binarized: binarized };
 }
 exports.binarize = binarize;
 

diff --git a/src/BitMatrix.ts b/src/BitMatrix.ts
@@ -31,8 +31,4 @@ export class BitMatrix {
       }
     }
   }
-
-  public getInverted() {
-    return new BitMatrix(this.data.map(d => d === 0 ? 1 : 0), this.width);
-  }
 }
diff --git a/src/binarizer/index.ts b/src/binarizer/index.ts
@@ -23,7 +23,7 @@ class Matrix {
   }
 }
 
-export function binarize(data: Uint8ClampedArray, width: number, height: number): BitMatrix {
+export function binarize(data: Uint8ClampedArray, width: number, height: number, returnInverted: boolean) {
   if (data.length !== width * height * 4) {
     throw new Error("Malformed data passed to binarizer.");
   }
@@ -88,6 +88,10 @@ export function binarize(data: Uint8ClampedArray, width: number, height: number)
   }
 
   const binarized = BitMatrix.createEmpty(width, height);
+  let inverted: BitMatrix = null;
+  if (returnInverted) {
+    inverted = BitMatrix.createEmpty(width, height);
+  }
   for (let verticalRegion = 0; verticalRegion < verticalRegionCount; verticalRegion++) {
     for (let hortizontalRegion = 0; hortizontalRegion < horizontalRegionCount; hortizontalRegion++) {
       const left = numBetween(hortizontalRegion, 2, horizontalRegionCount - 3);
@@ -99,14 +103,21 @@ export function binarize(data: Uint8ClampedArray, width: number, height: number)
         }
       }
       const threshold = sum / 25;
-      for (let x = 0; x < REGION_SIZE; x++) {
-        for (let y = 0; y < REGION_SIZE; y++) {
-          const lum = greyscalePixels.get(hortizontalRegion * REGION_SIZE + x, verticalRegion * REGION_SIZE + y);
-          binarized.set(hortizontalRegion * REGION_SIZE + x, verticalRegion * REGION_SIZE + y, lum <= threshold);
+      for (let xRegion = 0; xRegion < REGION_SIZE; xRegion++) {
+        for (let yRegion = 0; yRegion < REGION_SIZE; yRegion++) {
+          const x = hortizontalRegion * REGION_SIZE + xRegion;
+          const y = verticalRegion * REGION_SIZE + yRegion;
+          const lum = greyscalePixels.get(x, y);
+          binarized.set(x, y, lum <= threshold);
+          if (returnInverted) {
+            inverted.set(x, y, !(lum <= threshold));
+          }
         }
       }
     }
   }
-
-  return binarized;
+  if (returnInverted) {
+    return { binarized, inverted };
+  }
+  return { binarized };
 }
diff --git a/src/index.ts b/src/index.ts
@@ -54,11 +54,27 @@ function scan(matrix: BitMatrix): QRCode | null {
   };
 }
 
-function jsQR(data: Uint8ClampedArray, width: number, height: number): QRCode | null {
-  const binarized = binarize(data, width, height);
-  let result = scan(binarized);
-  if (!result) {
-    result = scan(binarized.getInverted());
+export interface Options {
+  inversionAttempts?: "dontInvert" | "onlyInvert" | "attemptBoth" | "invertFirst";
+}
+
+const defaultOptions: Options = {
+  inversionAttempts: "attemptBoth",
+};
+
+function jsQR(data: Uint8ClampedArray, width: number, height: number, providedOptions: Options = {}): QRCode | null {
+
+  const options = defaultOptions;
+  Object.keys(options || {}).forEach(opt => { // Sad implementation of Object.assign since we target es5 not es6
+    (options as any)[opt] = (providedOptions as any)[opt] || (options as any)[opt];
+  });
+
+  const shouldInvert = options.inversionAttempts === "attemptBoth" || options.inversionAttempts === "invertFirst";
+  const tryInvertedFirst = options.inversionAttempts === "onlyInvert" || options.inversionAttempts === "invertFirst";
+  const {binarized, inverted} = binarize(data, width, height, shouldInvert);
+  let result = scan(tryInvertedFirst ? inverted : binarized);
+  if (!result && (options.inversionAttempts === "attemptBoth" || options.inversionAttempts === "invertFirst")) {
+    result = scan(tryInvertedFirst ? binarized : inverted);
   }
   return result;
 }
-Original file line number
+Diff line change
@@ Expand Up / @@ -31,8 +31,4 @@ export class BitMatrix { @@
           }
         }
       }
-      public getInverted() {
-        return new BitMatrix(this.data.map(d => d === 0 ? 1 : 0), this.width);
-      }
     }