@zxing/library
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TypeScript port of ZXing multi-format 1D/2D barcode image processing library.
261 lines (260 loc) • 11.3 kB
JavaScript
"use strict";
/*
* Copyright 2010 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
Object.defineProperty(exports, "__esModule", { value: true });
var ResultPoint_1 = require("../../ResultPoint");
var NotFoundException_1 = require("../../NotFoundException");
/**
* @author Mariusz Dąbrowski
*/
var CornerDetector = /** @class */ (function () {
/**
* @throws NotFoundException if image is too small to accommodate {@code initSize}
*/
function CornerDetector(image, initSize, x, y, targetMatrixSize) {
this.image = image;
this.height = image.getHeight();
this.width = image.getWidth();
var halfsize = initSize / 2;
this.leftInit = x - halfsize;
this.rightInit = x + halfsize;
this.upInit = y - halfsize;
this.downInit = y + halfsize;
this.targetMatrixSize = targetMatrixSize * 2;
if (this.upInit < 0 || this.leftInit < 0 || this.downInit >= this.height || this.rightInit >= this.width) {
throw new NotFoundException_1.default();
}
}
/**
* @throws NotFoundException if no Data Matrix Code can be found
*/
CornerDetector.prototype.detect = function () {
var left = this.leftInit;
var right = this.rightInit;
var up = this.upInit;
var down = this.downInit;
var sizeExceeded = false;
var aBlackPointFoundOnBorder = true;
var atLeastOneBlackPointFoundOnBorder = false;
var atLeastOneBlackPointFoundOnRight = false;
var atLeastOneBlackPointFoundOnBottom = false;
var atLeastOneBlackPointFoundOnLeft = false;
var atLeastOneBlackPointFoundOnTop = false;
while (aBlackPointFoundOnBorder) {
aBlackPointFoundOnBorder = false;
// .....
// . |
// .....
var rightBorderNotWhite = true;
while ((rightBorderNotWhite || !atLeastOneBlackPointFoundOnRight) && right < this.width) {
rightBorderNotWhite = this.containsBlackPoint(up, down, right, false);
if (rightBorderNotWhite) {
right++;
aBlackPointFoundOnBorder = true;
atLeastOneBlackPointFoundOnRight = true;
}
else if (!atLeastOneBlackPointFoundOnRight) {
right++;
}
}
if (right >= this.width) {
sizeExceeded = true;
break;
}
// .....
// . .
// .___.
var bottomBorderNotWhite = true;
while ((bottomBorderNotWhite || !atLeastOneBlackPointFoundOnBottom) && down < this.height) {
bottomBorderNotWhite = this.containsBlackPoint(left, right, down, true);
if (bottomBorderNotWhite) {
down++;
aBlackPointFoundOnBorder = true;
atLeastOneBlackPointFoundOnBottom = true;
}
else if (!atLeastOneBlackPointFoundOnBottom) {
down++;
}
}
if (down >= this.height) {
sizeExceeded = true;
break;
}
// .....
// | .
// .....
var leftBorderNotWhite = true;
while ((leftBorderNotWhite || !atLeastOneBlackPointFoundOnLeft) && left >= 0) {
leftBorderNotWhite = this.containsBlackPoint(up, down, left, false);
if (leftBorderNotWhite) {
left--;
aBlackPointFoundOnBorder = true;
atLeastOneBlackPointFoundOnLeft = true;
}
else if (!atLeastOneBlackPointFoundOnLeft) {
left--;
}
}
if (left < 0) {
sizeExceeded = true;
break;
}
// .___.
// . .
// .....
var topBorderNotWhite = true;
while ((topBorderNotWhite || !atLeastOneBlackPointFoundOnTop) && up >= 0) {
topBorderNotWhite = this.containsBlackPoint(left, right, up, true);
if (topBorderNotWhite) {
up--;
aBlackPointFoundOnBorder = true;
atLeastOneBlackPointFoundOnTop = true;
}
else if (!atLeastOneBlackPointFoundOnTop) {
up--;
}
}
if (up < 0) {
sizeExceeded = true;
break;
}
if (aBlackPointFoundOnBorder) {
atLeastOneBlackPointFoundOnBorder = true;
}
}
if (!sizeExceeded && atLeastOneBlackPointFoundOnBorder) {
return this.findCorners(right, left, down, up);
}
else {
throw new NotFoundException_1.default();
}
};
CornerDetector.prototype.findCorners = function (right, left, down, up) {
//
// A------------ ------------B
// | | up | |
// | -------|--------------|------- |
// | | | | | |
// | | | | | |
// ------------AP BP------------
// | |
// | |
// left | | right
// | |
// | |
// ------------DP CP------------
// | | | | | |
// | | | down | | |
// | -------|-------------|-------- |
// | | | |
// D-----------| |------------C
//
var width = right - left;
var height = down - up;
var sampler = 16 / this.targetMatrixSize;
var sampler2 = 4 / this.targetMatrixSize;
var deltaX = width * sampler2;
var deltaY = height * sampler2;
var areaWidth = deltaX + (right - left) * sampler;
var areaHeight = deltaY + (down - up) * sampler;
var a = new ResultPoint_1.default(left - deltaX, up - deltaY);
var b = new ResultPoint_1.default(right + deltaX, up - deltaY);
var c = new ResultPoint_1.default(right + deltaX, down + deltaY);
var d = new ResultPoint_1.default(left - deltaX, down + deltaY);
var ap = new ResultPoint_1.default(a.getX() + areaWidth, a.getY() + areaHeight);
var bp = new ResultPoint_1.default(b.getX() - areaWidth, b.getY() + areaHeight);
var cp = new ResultPoint_1.default(c.getX() - areaWidth, c.getY() - areaHeight);
var dp = new ResultPoint_1.default(d.getX() + areaWidth, d.getY() - areaHeight);
var topLeftCorner = this.getCornerFromArea(a.getX(), ap.getX(), a.getY(), ap.getY(), false, false);
var topRightCorner = this.getCornerFromArea(bp.getX(), b.getX(), b.getY(), bp.getY(), true, false);
var bottomRightCorner = this.getCornerFromArea(cp.getX(), c.getX(), cp.getY(), c.getY(), true, true);
var bottomLeftCorner = this.getCornerFromArea(d.getX(), dp.getX(), dp.getY(), d.getY(), false, true);
var xCorrection = (topRightCorner.getX() - topLeftCorner.getX()) / this.targetMatrixSize;
var yCorrection = (bottomRightCorner.getY() - topRightCorner.getY()) / this.targetMatrixSize;
var topLeftCornerCenter = new ResultPoint_1.default(topLeftCorner.getX() + xCorrection, topLeftCorner.getY() + yCorrection);
var topRightCornerCenter = new ResultPoint_1.default(topRightCorner.getX() - xCorrection, topRightCorner.getY() + yCorrection);
var bottomRightCornerCenter = new ResultPoint_1.default(bottomRightCorner.getX() - xCorrection, bottomRightCorner.getY() - yCorrection);
var bottomLeftCornerCenter = new ResultPoint_1.default(bottomLeftCorner.getX() + xCorrection, bottomLeftCorner.getY() - yCorrection);
var result = [topLeftCornerCenter, topRightCornerCenter, bottomRightCornerCenter, bottomLeftCornerCenter];
return result;
};
CornerDetector.prototype.getCornerFromArea = function (left, right, top, bottom, maximizeX, maximizeY) {
var resX = maximizeX ? 0 : Number.MAX_VALUE;
var resY = maximizeY ? 0 : Number.MAX_VALUE;
for (var x = left; x < right; x++) {
for (var y = top; y < bottom; y++) {
if (x > 0 && y > 0 && x < this.image.getWidth() && y < this.image.getHeight()) {
if (this.image.get(x, y)) {
if (maximizeX) {
if (x > resX) {
resX = x;
}
}
else {
if (x < resX) {
resX = x;
}
}
if (maximizeY) {
if (y > resY) {
resY = y;
}
}
else {
if (y < resY) {
resY = y;
}
}
}
}
}
}
if (resX === 0 || resY === 0) {
throw new NotFoundException_1.default();
}
else {
return new ResultPoint_1.default(resX, resY);
}
};
/**
* Determines whether a segment contains a black point
*
* @param a min value of the scanned coordinate
* @param b max value of the scanned coordinate
* @param fixed value of fixed coordinate
* @param horizontal set to true if scan must be horizontal, false if vertical
* @return true if a black point has been found, else false.
*/
CornerDetector.prototype.containsBlackPoint = function (a, b, fixed, horizontal) {
if (horizontal) {
for (var x = a; x <= b; x++) {
if (this.image.get(x, fixed)) {
return true;
}
}
}
else {
for (var y = a; y <= b; y++) {
if (this.image.get(fixed, y)) {
return true;
}
}
}
return false;
};
return CornerDetector;
}());
exports.default = CornerDetector;