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perf: Changed Array to Uint8Array #59

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perf: Changed Array to Uint8Array #59

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810f24a
Optimized arrays & timer
Mar 22, 2019
4812c8e
Eliminated Lint error
less-mine Mar 25, 2019
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46 changes: 24 additions & 22 deletions src/qrcode.js
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Original file line number Diff line number Diff line change
Expand Up @@ -111,7 +111,9 @@ QrCode.prototype.decode_utf8 = function(s) {

QrCode.prototype.process = function(imageData) {

var start = new Date().getTime();
if (this.debug) {
var start = Date.now();
}

var image = this.grayScaleToBitmap(this.grayscale(imageData));

Expand All @@ -138,28 +140,26 @@ QrCode.prototype.process = function(imageData) {
str += String.fromCharCode(data[i][j]);
}

var end = new Date().getTime();
var time = end - start;
if (this.debug) {
var end = Date.now();
var time = end - start;

console.log('QR Code processing time (ms): ' + time);
}

return {result: this.decode_utf8(str), points: qRCodeMatrix.points};
};

QrCode.prototype.getPixel = function(imageData, x, y) {
if (imageData.width < x) {
throw "point error";
}
if (imageData.height < y) {
if (imageData.width < x || imageData.height < y) {
throw "point error";
}
var point = (x * 4) + (y * imageData.width * 4);
return (imageData.data[point] * 33 + imageData.data[point + 1] * 34 + imageData.data[point + 2] * 33) / 100;
};

QrCode.prototype.binarize = function(th) {
var ret = new Array(this.width * this.height);
var ret = new Uint8ClampedArray(this.width * this.height);
for (var y = 0; y < this.height; y++) {
for (var x = 0; x < this.width; x++) {
var gray = this.getPixel(x, y);
Expand All @@ -173,11 +173,11 @@ QrCode.prototype.binarize = function(th) {
QrCode.prototype.getMiddleBrightnessPerArea = function(imageData) {
var numSqrtArea = 4;
//obtain middle brightness((min + max) / 2) per area
var areaWidth = Math.floor(imageData.width / numSqrtArea);
var areaHeight = Math.floor(imageData.height / numSqrtArea);
var minmax = new Array(numSqrtArea);
var areaWidth = (imageData.width / numSqrtArea) | 0;
var areaHeight = (imageData.height / numSqrtArea) | 0;
var minmax = [];
for (var i = 0; i < numSqrtArea; i++) {
minmax[i] = new Array(numSqrtArea);
minmax[i] = [];
for (var i2 = 0; i2 < numSqrtArea; i2++) {
minmax[i][i2] = [0, 0];
}
Expand All @@ -196,13 +196,13 @@ QrCode.prototype.getMiddleBrightnessPerArea = function(imageData) {
}
}
}
var middle = new Array(numSqrtArea);
var middle = [];
for (var i3 = 0; i3 < numSqrtArea; i3++) {
middle[i3] = new Array(numSqrtArea);
middle[i3] = [];
}
for (var ay = 0; ay < numSqrtArea; ay++) {
for (var ax = 0; ax < numSqrtArea; ax++) {
middle[ax][ay] = Math.floor((minmax[ax][ay][0] + minmax[ax][ay][1]) / 2);
middle[ax][ay] = ((minmax[ax][ay][0] + minmax[ax][ay][1]) / 2) | 0;
}
}

Expand All @@ -212,13 +212,15 @@ QrCode.prototype.getMiddleBrightnessPerArea = function(imageData) {
QrCode.prototype.grayScaleToBitmap = function(grayScaleImageData) {
var middle = this.getMiddleBrightnessPerArea(grayScaleImageData);
var sqrtNumArea = middle.length;
var areaWidth = Math.floor(grayScaleImageData.width / sqrtNumArea);
var areaHeight = Math.floor(grayScaleImageData.height / sqrtNumArea);
var areaWidth = (grayScaleImageData.width / sqrtNumArea) | 0;
var areaHeight = (grayScaleImageData.height / sqrtNumArea) | 0;

for (var ay = 0; ay < sqrtNumArea; ay++) {
for (var ax = 0; ax < sqrtNumArea; ax++) {
for (var dy = 0; dy < areaHeight; dy++) {
for (var dx = 0; dx < areaWidth; dx++) {
var ay, ax, dy, dx;

for (ay = 0; ay < sqrtNumArea; ay++) {
for (ax = 0; ax < sqrtNumArea; ax++) {
for (dy = 0; dy < areaHeight; dy++) {
for (dx = 0; dx < areaWidth; dx++) {
grayScaleImageData.data[areaWidth * ax + dx + (areaHeight * ay + dy) * grayScaleImageData.width] = (grayScaleImageData.data[areaWidth * ax + dx + (areaHeight * ay + dy) * grayScaleImageData.width] < middle[ax][ay]);
}
}
Expand All @@ -228,7 +230,7 @@ QrCode.prototype.grayScaleToBitmap = function(grayScaleImageData) {
};

QrCode.prototype.grayscale = function(imageData) {
var ret = new Array(imageData.width * imageData.height);
var ret = new Uint8ClampedArray(imageData.width * imageData.height);

for (var y = 0; y < imageData.height; y++) {
for (var x = 0; x < imageData.width; x++) {
Expand Down