src/core/pdf417/decoder/PDF417ScanningDecoder.ts
/*
* Copyright 2013 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.
*/
// package com.google.zxing.pdf417.decoder;
// import com.google.zxing.ChecksumException;
import ChecksumException from '../../ChecksumException';
// import com.google.zxing.FormatException;
import FormatException from '../../FormatException';
// import com.google.zxing.NotFoundException;
import NotFoundException from '../../NotFoundException';
// import com.google.zxing.ResultPoint;
import ResultPoint from '../../ResultPoint';
// import com.google.zxing.common.BitMatrix;
import BitMatrix from '../../common/BitMatrix';
// import com.google.zxing.common.DecoderResult;
import DecoderResult from '../../common/DecoderResult';
// import com.google.zxing.common.detector.MathUtils;
import MathUtils from '../../common/detector/MathUtils';
// import com.google.zxing.pdf417.PDF417Common;
import PDF417Common from '../PDF417Common';
// import com.google.zxing.pdf417.decoder.ec.ErrorCorrection;
import ErrorCorrection from './ec/ErrorCorrection';
// local
import BoundingBox from './BoundingBox';
import DetectionResultRowIndicatorColumn from './DetectionResultRowIndicatorColumn';
import DetectionResult from './DetectionResult';
import DetectionResultColumn from './DetectionResultColumn';
import Codeword from './Codeword';
import BarcodeMetadata from './BarcodeMetadata';
import BarcodeValue from './BarcodeValue';
import PDF417CodewordDecoder from './PDF417CodewordDecoder';
import DecodedBitStreamParser from './DecodedBitStreamParser';
// utils
import Formatter from '../../util/Formatter';
import { int, List, Collection } from '../../../customTypings';
// import java.util.ArrayList;
// import java.util.Collection;
// import java.util.Formatter;
// import java.util.List;
/**
* @author Guenther Grau
*/
export default /*public final*/ class PDF417ScanningDecoder {
/*final*/ static CODEWORD_SKEW_SIZE: int = 2;
/*final*/ static MAX_ERRORS: int = 3;
/*final*/ static MAX_EC_CODEWORDS: int = 512;
/*final*/ static errorCorrection: ErrorCorrection = new ErrorCorrection();
private constructor() {}
/**
* @TODO don't pass in minCodewordWidth and maxCodewordWidth, pass in barcode columns for start and stop pattern
*
* columns. That way width can be deducted from the pattern column.
* This approach also allows to detect more details about the barcode, e.g. if a bar type (white or black) is wider
* than it should be. This can happen if the scanner used a bad blackpoint.
*
* @param BitMatrix
* @param image
* @param ResultPoint
* @param imageTopLeft
* @param ResultPoint
* @param imageBottomLeft
* @param ResultPoint
* @param imageTopRight
* @param ResultPoint
* @param imageBottomRight
* @param int
* @param minCodewordWidth
* @param int
* @param maxCodewordWidth
*
* @throws NotFoundException
* @throws FormatException
* @throws ChecksumException
*/
public static decode(image: BitMatrix,
imageTopLeft: ResultPoint,
imageBottomLeft: ResultPoint,
imageTopRight: ResultPoint,
imageBottomRight: ResultPoint,
minCodewordWidth: int,
maxCodewordWidth: int): DecoderResult {
let boundingBox: BoundingBox = new BoundingBox(image, imageTopLeft, imageBottomLeft, imageTopRight, imageBottomRight);
let leftRowIndicatorColumn: DetectionResultRowIndicatorColumn = null;
let rightRowIndicatorColumn: DetectionResultRowIndicatorColumn = null;
let detectionResult: DetectionResult;
for (let firstPass /*boolean*/ = true; ; firstPass = false) {
if (imageTopLeft != null) {
leftRowIndicatorColumn = PDF417ScanningDecoder.getRowIndicatorColumn(image, boundingBox, imageTopLeft, true, minCodewordWidth,
maxCodewordWidth);
}
if (imageTopRight != null) {
rightRowIndicatorColumn = PDF417ScanningDecoder.getRowIndicatorColumn(image, boundingBox, imageTopRight, false, minCodewordWidth,
maxCodewordWidth);
}
detectionResult = PDF417ScanningDecoder.merge(leftRowIndicatorColumn, rightRowIndicatorColumn);
if (detectionResult == null) {
throw NotFoundException.getNotFoundInstance();
}
let resultBox: BoundingBox = detectionResult.getBoundingBox();
if (firstPass && resultBox != null &&
(resultBox.getMinY() < boundingBox.getMinY() || resultBox.getMaxY() > boundingBox.getMaxY())) {
boundingBox = resultBox;
} else {
break;
}
}
detectionResult.setBoundingBox(boundingBox);
let maxBarcodeColumn: int = detectionResult.getBarcodeColumnCount() + 1;
detectionResult.setDetectionResultColumn(0, leftRowIndicatorColumn);
detectionResult.setDetectionResultColumn(maxBarcodeColumn, rightRowIndicatorColumn);
let leftToRight: boolean = leftRowIndicatorColumn != null;
for (let barcodeColumnCount /*int*/ = 1; barcodeColumnCount <= maxBarcodeColumn; barcodeColumnCount++) {
let barcodeColumn: int = leftToRight ? barcodeColumnCount : maxBarcodeColumn - barcodeColumnCount;
if (detectionResult.getDetectionResultColumn(barcodeColumn) !== /* null */ undefined) {
// This will be the case for the opposite row indicator column, which doesn't need to be decoded again.
continue;
}
let detectionResultColumn: DetectionResultColumn;
if (barcodeColumn === 0 || barcodeColumn === maxBarcodeColumn) {
detectionResultColumn = new DetectionResultRowIndicatorColumn(boundingBox, barcodeColumn === 0);
} else {
detectionResultColumn = new DetectionResultColumn(boundingBox);
}
detectionResult.setDetectionResultColumn(barcodeColumn, detectionResultColumn);
let startColumn: int = -1;
let previousStartColumn: int = startColumn;
// TODO start at a row for which we know the start position, then detect upwards and downwards from there.
for (let imageRow /*int*/ = boundingBox.getMinY(); imageRow <= boundingBox.getMaxY(); imageRow++) {
startColumn = PDF417ScanningDecoder.getStartColumn(detectionResult, barcodeColumn, imageRow, leftToRight);
if (startColumn < 0 || startColumn > boundingBox.getMaxX()) {
if (previousStartColumn === -1) {
continue;
}
startColumn = previousStartColumn;
}
let codeword: Codeword = PDF417ScanningDecoder.detectCodeword(image, boundingBox.getMinX(), boundingBox.getMaxX(), leftToRight,
startColumn, imageRow, minCodewordWidth, maxCodewordWidth);
if (codeword != null) {
detectionResultColumn.setCodeword(imageRow, codeword);
previousStartColumn = startColumn;
minCodewordWidth = Math.min(minCodewordWidth, codeword.getWidth());
maxCodewordWidth = Math.max(maxCodewordWidth, codeword.getWidth());
}
}
}
return PDF417ScanningDecoder.createDecoderResult(detectionResult);
}
/**
*
* @param leftRowIndicatorColumn
* @param rightRowIndicatorColumn
*
* @throws NotFoundException
*/
private static merge(leftRowIndicatorColumn: DetectionResultRowIndicatorColumn,
rightRowIndicatorColumn: DetectionResultRowIndicatorColumn): DetectionResult {
if (leftRowIndicatorColumn == null && rightRowIndicatorColumn == null) {
return null;
}
let barcodeMetadata: BarcodeMetadata = PDF417ScanningDecoder.getBarcodeMetadata(leftRowIndicatorColumn, rightRowIndicatorColumn);
if (barcodeMetadata == null) {
return null;
}
let boundingBox: BoundingBox = BoundingBox.merge(PDF417ScanningDecoder.adjustBoundingBox(leftRowIndicatorColumn),
PDF417ScanningDecoder.adjustBoundingBox(rightRowIndicatorColumn));
return new DetectionResult(barcodeMetadata, boundingBox);
}
/**
*
* @param rowIndicatorColumn
*
* @throws NotFoundException
*/
private static adjustBoundingBox(rowIndicatorColumn: DetectionResultRowIndicatorColumn): BoundingBox {
if (rowIndicatorColumn == null) {
return null;
}
let rowHeights: Int32Array = rowIndicatorColumn.getRowHeights();
if (rowHeights == null) {
return null;
}
let maxRowHeight: int = PDF417ScanningDecoder.getMax(rowHeights);
let missingStartRows: int = 0;
for (let rowHeight /*int*/ of rowHeights) {
missingStartRows += maxRowHeight - rowHeight;
if (rowHeight > 0) {
break;
}
}
let codewords: Codeword[] = rowIndicatorColumn.getCodewords();
for (let row /*int*/ = 0; missingStartRows > 0 && codewords[row] == null; row++) {
missingStartRows--;
}
let missingEndRows: int = 0;
for (let row /*int*/ = rowHeights.length - 1; row >= 0; row--) {
missingEndRows += maxRowHeight - rowHeights[row];
if (rowHeights[row] > 0) {
break;
}
}
for (let row /*int*/ = codewords.length - 1; missingEndRows > 0 && codewords[row] == null; row--) {
missingEndRows--;
}
return rowIndicatorColumn.getBoundingBox().addMissingRows(missingStartRows, missingEndRows,
rowIndicatorColumn.isLeft());
}
private static getMax(values: Int32Array): int {
let maxValue: int = -1;
for (let value /*int*/ of values) {
maxValue = Math.max(maxValue, value);
}
return maxValue;
}
private static getBarcodeMetadata(leftRowIndicatorColumn: DetectionResultRowIndicatorColumn,
rightRowIndicatorColumn: DetectionResultRowIndicatorColumn): BarcodeMetadata {
let leftBarcodeMetadata: BarcodeMetadata;
if (leftRowIndicatorColumn == null ||
(leftBarcodeMetadata = leftRowIndicatorColumn.getBarcodeMetadata()) == null) {
return rightRowIndicatorColumn == null ? null : rightRowIndicatorColumn.getBarcodeMetadata();
}
let rightBarcodeMetadata: BarcodeMetadata;
if (rightRowIndicatorColumn == null ||
(rightBarcodeMetadata = rightRowIndicatorColumn.getBarcodeMetadata()) == null) {
return leftBarcodeMetadata;
}
if (leftBarcodeMetadata.getColumnCount() !== rightBarcodeMetadata.getColumnCount() &&
leftBarcodeMetadata.getErrorCorrectionLevel() !== rightBarcodeMetadata.getErrorCorrectionLevel() &&
leftBarcodeMetadata.getRowCount() !== rightBarcodeMetadata.getRowCount()) {
return null;
}
return leftBarcodeMetadata;
}
private static getRowIndicatorColumn(image: BitMatrix,
boundingBox: BoundingBox,
startPoint: ResultPoint,
leftToRight: boolean,
minCodewordWidth: int,
maxCodewordWidth: int): DetectionResultRowIndicatorColumn {
let rowIndicatorColumn: DetectionResultRowIndicatorColumn = new DetectionResultRowIndicatorColumn(boundingBox,
leftToRight);
for (let i /*int*/ = 0; i < 2; i++) {
let increment: int = i === 0 ? 1 : -1;
let startColumn: int = Math.trunc(<int>Math.trunc(startPoint.getX()));
for (let imageRow /*int*/ = Math.trunc(<int>Math.trunc(startPoint.getY())); imageRow <= boundingBox.getMaxY() &&
imageRow >= boundingBox.getMinY(); imageRow += increment) {
let codeword: Codeword = PDF417ScanningDecoder.detectCodeword(image, 0, image.getWidth(), leftToRight, startColumn, imageRow,
minCodewordWidth, maxCodewordWidth);
if (codeword != null) {
rowIndicatorColumn.setCodeword(imageRow, codeword);
if (leftToRight) {
startColumn = codeword.getStartX();
} else {
startColumn = codeword.getEndX();
}
}
}
}
return rowIndicatorColumn;
}
/**
*
* @param detectionResult
* @param BarcodeValue
* @param param2
* @param param3
* @param barcodeMatrix
*
* @throws NotFoundException
*/
private static adjustCodewordCount(detectionResult: DetectionResult, barcodeMatrix: BarcodeValue[][]): void {
let barcodeMatrix01: BarcodeValue = barcodeMatrix[0][1];
let numberOfCodewords: Int32Array = barcodeMatrix01.getValue();
let calculatedNumberOfCodewords: int = detectionResult.getBarcodeColumnCount() *
detectionResult.getBarcodeRowCount() -
PDF417ScanningDecoder.getNumberOfECCodeWords(detectionResult.getBarcodeECLevel());
if (numberOfCodewords.length === 0) {
if (calculatedNumberOfCodewords < 1 || calculatedNumberOfCodewords > PDF417Common.MAX_CODEWORDS_IN_BARCODE) {
throw NotFoundException.getNotFoundInstance();
}
barcodeMatrix01.setValue(calculatedNumberOfCodewords);
} else if (numberOfCodewords[0] !== calculatedNumberOfCodewords) {
// The calculated one is more reliable as it is derived from the row indicator columns
barcodeMatrix01.setValue(calculatedNumberOfCodewords);
}
}
/**
*
* @param detectionResult
*
* @throws FormatException
* @throws ChecksumException
* @throws NotFoundException
*/
private static createDecoderResult(detectionResult: DetectionResult): DecoderResult {
let barcodeMatrix: BarcodeValue[][] = PDF417ScanningDecoder.createBarcodeMatrix(detectionResult);
PDF417ScanningDecoder.adjustCodewordCount(detectionResult, barcodeMatrix);
let erasures /*Collection<Integer>*/ = new Array<number>();
let codewords: Int32Array = new Int32Array(detectionResult.getBarcodeRowCount() * detectionResult.getBarcodeColumnCount());
let ambiguousIndexValuesList: /*List<int[]>*/ List<Int32Array> = [];
let ambiguousIndexesList: /*Collection<Integer>*/ Collection<int> = new Array<int>();
for (let row /*int*/ = 0; row < detectionResult.getBarcodeRowCount(); row++) {
for (let column /*int*/ = 0; column < detectionResult.getBarcodeColumnCount(); column++) {
let values: Int32Array = barcodeMatrix[row][column + 1].getValue();
let codewordIndex: int = row * detectionResult.getBarcodeColumnCount() + column;
if (values.length === 0) {
erasures.push(codewordIndex);
} else if (values.length === 1) {
codewords[codewordIndex] = values[0];
} else {
ambiguousIndexesList.push(codewordIndex);
ambiguousIndexValuesList.push(values);
}
}
}
let ambiguousIndexValues: Int32Array[] = new Array<Int32Array>(ambiguousIndexValuesList.length);
for (let i /*int*/ = 0; i < ambiguousIndexValues.length; i++) {
ambiguousIndexValues[i] = ambiguousIndexValuesList[i];
}
return PDF417ScanningDecoder.createDecoderResultFromAmbiguousValues(detectionResult.getBarcodeECLevel(), codewords,
PDF417Common.toIntArray(erasures), PDF417Common.toIntArray(ambiguousIndexesList), ambiguousIndexValues);
}
/**
* This method deals with the fact, that the decoding process doesn't always yield a single most likely value. The
* current error correction implementation doesn't deal with erasures very well, so it's better to provide a value
* for these ambiguous codewords instead of treating it as an erasure. The problem is that we don't know which of
* the ambiguous values to choose. We try decode using the first value, and if that fails, we use another of the
* ambiguous values and try to decode again. This usually only happens on very hard to read and decode barcodes,
* so decoding the normal barcodes is not affected by this.
*
* @param erasureArray contains the indexes of erasures
* @param ambiguousIndexes array with the indexes that have more than one most likely value
* @param ambiguousIndexValues two dimensional array that contains the ambiguous values. The first dimension must
* be the same length as the ambiguousIndexes array
*
* @throws FormatException
* @throws ChecksumException
*/
private static createDecoderResultFromAmbiguousValues(ecLevel: int,
codewords: Int32Array,
erasureArray: Int32Array,
ambiguousIndexes: Int32Array,
ambiguousIndexValues: Int32Array[]): DecoderResult {
let ambiguousIndexCount: Int32Array = new Int32Array(ambiguousIndexes.length);
let tries: int = 100;
while (tries-- > 0) {
for (let i /*int*/ = 0; i < ambiguousIndexCount.length; i++) {
codewords[ambiguousIndexes[i]] = ambiguousIndexValues[i][ambiguousIndexCount[i]];
}
try {
return PDF417ScanningDecoder.decodeCodewords(codewords, ecLevel, erasureArray);
} catch (err) {
let ignored = err instanceof ChecksumException;
if (!ignored) {
throw err;
}
}
if (ambiguousIndexCount.length === 0) {
throw ChecksumException.getChecksumInstance();
}
for (let i /*int*/ = 0; i < ambiguousIndexCount.length; i++) {
if (ambiguousIndexCount[i] < ambiguousIndexValues[i].length - 1) {
ambiguousIndexCount[i]++;
break;
} else {
ambiguousIndexCount[i] = 0;
if (i === ambiguousIndexCount.length - 1) {
throw ChecksumException.getChecksumInstance();
}
}
}
}
throw ChecksumException.getChecksumInstance();
}
private static createBarcodeMatrix(detectionResult: DetectionResult): BarcodeValue[][] {
// let barcodeMatrix: BarcodeValue[][] =
// new BarcodeValue[detectionResult.getBarcodeRowCount()][detectionResult.getBarcodeColumnCount() + 2];
let barcodeMatrix: BarcodeValue[][] =
Array.from({ length: detectionResult.getBarcodeRowCount() }, () => new Array(detectionResult.getBarcodeColumnCount() + 2));
for (let row /*int*/ = 0; row < barcodeMatrix.length; row++) {
for (let column /*int*/ = 0; column < barcodeMatrix[row].length; column++) {
barcodeMatrix[row][column] = new BarcodeValue();
}
}
let column: int = 0;
for (let detectionResultColumn /*DetectionResultColumn*/ of detectionResult.getDetectionResultColumns()) {
if (detectionResultColumn != null) {
for (let codeword /*Codeword*/ of detectionResultColumn.getCodewords()) {
if (codeword != null) {
let rowNumber: int = codeword.getRowNumber();
if (rowNumber >= 0) {
if (rowNumber >= barcodeMatrix.length) {
// We have more rows than the barcode metadata allows for, ignore them.
continue;
}
barcodeMatrix[rowNumber][column].setValue(codeword.getValue());
}
}
}
}
column++;
}
return barcodeMatrix;
}
private static isValidBarcodeColumn(detectionResult: DetectionResult, barcodeColumn: int): boolean {
return barcodeColumn >= 0 && barcodeColumn <= detectionResult.getBarcodeColumnCount() + 1;
}
private static getStartColumn(detectionResult: DetectionResult,
barcodeColumn: int,
imageRow: int,
leftToRight: boolean): int {
let offset: int = leftToRight ? 1 : -1;
let codeword: Codeword = null;
if (PDF417ScanningDecoder.isValidBarcodeColumn(detectionResult, barcodeColumn - offset)) {
codeword = detectionResult.getDetectionResultColumn(barcodeColumn - offset).getCodeword(imageRow);
}
if (codeword != null) {
return leftToRight ? codeword.getEndX() : codeword.getStartX();
}
codeword = detectionResult.getDetectionResultColumn(barcodeColumn).getCodewordNearby(imageRow);
if (codeword != null) {
return leftToRight ? codeword.getStartX() : codeword.getEndX();
}
if (PDF417ScanningDecoder.isValidBarcodeColumn(detectionResult, barcodeColumn - offset)) {
codeword = detectionResult.getDetectionResultColumn(barcodeColumn - offset).getCodewordNearby(imageRow);
}
if (codeword != null) {
return leftToRight ? codeword.getEndX() : codeword.getStartX();
}
let skippedColumns: int = 0;
while (PDF417ScanningDecoder.isValidBarcodeColumn(detectionResult, barcodeColumn - offset)) {
barcodeColumn -= offset;
for (let previousRowCodeword /*Codeword*/ of detectionResult.getDetectionResultColumn(barcodeColumn).getCodewords()) {
if (previousRowCodeword != null) {
return (leftToRight ? previousRowCodeword.getEndX() : previousRowCodeword.getStartX()) +
offset *
skippedColumns *
(previousRowCodeword.getEndX() - previousRowCodeword.getStartX());
}
}
skippedColumns++;
}
return leftToRight ? detectionResult.getBoundingBox().getMinX() : detectionResult.getBoundingBox().getMaxX();
}
private static detectCodeword(image: BitMatrix,
minColumn: int,
maxColumn: int,
leftToRight: boolean,
startColumn: int,
imageRow: int,
minCodewordWidth: int,
maxCodewordWidth: int): Codeword {
startColumn = PDF417ScanningDecoder.adjustCodewordStartColumn(image, minColumn, maxColumn, leftToRight, startColumn, imageRow);
// we usually know fairly exact now how long a codeword is. We should provide minimum and maximum expected length
// and try to adjust the read pixels, e.g. remove single pixel errors or try to cut off exceeding pixels.
// min and maxCodewordWidth should not be used as they are calculated for the whole barcode an can be inaccurate
// for the current position
let moduleBitCount: Int32Array = PDF417ScanningDecoder.getModuleBitCount(image, minColumn, maxColumn, leftToRight, startColumn, imageRow);
if (moduleBitCount == null) {
return null;
}
let endColumn: int;
let codewordBitCount: int = MathUtils.sum(moduleBitCount);
if (leftToRight) {
endColumn = startColumn + codewordBitCount;
} else {
for (let i /*int*/ = 0; i < moduleBitCount.length / 2; i++) {
let tmpCount: int = moduleBitCount[i];
moduleBitCount[i] = moduleBitCount[moduleBitCount.length - 1 - i];
moduleBitCount[moduleBitCount.length - 1 - i] = tmpCount;
}
endColumn = startColumn;
startColumn = endColumn - codewordBitCount;
}
// TODO implement check for width and correction of black and white bars
// use start (and maybe stop pattern) to determine if black bars are wider than white bars. If so, adjust.
// should probably done only for codewords with a lot more than 17 bits.
// The following fixes 10-1.png, which has wide black bars and small white bars
// for (let i /*int*/ = 0; i < moduleBitCount.length; i++) {
// if (i % 2 === 0) {
// moduleBitCount[i]--;
// } else {
// moduleBitCount[i]++;
// }
// }
// We could also use the width of surrounding codewords for more accurate results, but this seems
// sufficient for now
if (!PDF417ScanningDecoder.checkCodewordSkew(codewordBitCount, minCodewordWidth, maxCodewordWidth)) {
// We could try to use the startX and endX position of the codeword in the same column in the previous row,
// create the bit count from it and normalize it to 8. This would help with single pixel errors.
return null;
}
let decodedValue: int = PDF417CodewordDecoder.getDecodedValue(moduleBitCount);
let codeword: int = PDF417Common.getCodeword(decodedValue);
if (codeword === -1) {
return null;
}
return new Codeword(startColumn, endColumn, PDF417ScanningDecoder.getCodewordBucketNumber(decodedValue), codeword);
}
private static getModuleBitCount(image: BitMatrix,
minColumn: int,
maxColumn: int,
leftToRight: boolean,
startColumn: int,
imageRow: int): Int32Array {
let imageColumn: int = startColumn;
let moduleBitCount: Int32Array = new Int32Array(8);
let moduleNumber: int = 0;
let increment: int = leftToRight ? 1 : -1;
let previousPixelValue: boolean = leftToRight;
while ((leftToRight ? imageColumn < maxColumn : imageColumn >= minColumn) &&
moduleNumber < moduleBitCount.length) {
if (image.get(imageColumn, imageRow) === previousPixelValue) {
moduleBitCount[moduleNumber]++;
imageColumn += increment;
} else {
moduleNumber++;
previousPixelValue = !previousPixelValue;
}
}
if (moduleNumber === moduleBitCount.length ||
((imageColumn === (leftToRight ? maxColumn : minColumn)) &&
moduleNumber === moduleBitCount.length - 1)) {
return moduleBitCount;
}
return null;
}
private static getNumberOfECCodeWords(barcodeECLevel: int): int {
return 2 << barcodeECLevel;
}
private static adjustCodewordStartColumn(image: BitMatrix,
minColumn: int,
maxColumn: int,
leftToRight: boolean,
codewordStartColumn: int,
imageRow: int): int {
let correctedStartColumn: int = codewordStartColumn;
let increment: int = leftToRight ? -1 : 1;
// there should be no black pixels before the start column. If there are, then we need to start earlier.
for (let i /*int*/ = 0; i < 2; i++) {
while ((leftToRight ? correctedStartColumn >= minColumn : correctedStartColumn < maxColumn) &&
leftToRight === image.get(correctedStartColumn, imageRow)) {
if (Math.abs(codewordStartColumn - correctedStartColumn) > PDF417ScanningDecoder.CODEWORD_SKEW_SIZE) {
return codewordStartColumn;
}
correctedStartColumn += increment;
}
increment = -increment;
leftToRight = !leftToRight;
}
return correctedStartColumn;
}
private static checkCodewordSkew(codewordSize: int, minCodewordWidth: int, maxCodewordWidth: int): boolean {
return minCodewordWidth - PDF417ScanningDecoder.CODEWORD_SKEW_SIZE <= codewordSize &&
codewordSize <= maxCodewordWidth + PDF417ScanningDecoder.CODEWORD_SKEW_SIZE;
}
/**
* @throws FormatException,
* @throws ChecksumException
*/
private static decodeCodewords(codewords: Int32Array, ecLevel: int, erasures: Int32Array): DecoderResult {
if (codewords.length === 0) {
throw FormatException.getFormatInstance();
}
let numECCodewords: int = 1 << (ecLevel + 1);
let correctedErrorsCount: int = PDF417ScanningDecoder.correctErrors(codewords, erasures, numECCodewords);
PDF417ScanningDecoder.verifyCodewordCount(codewords, numECCodewords);
// Decode the codewords
let decoderResult: DecoderResult = DecodedBitStreamParser.decode(codewords, '' + ecLevel);
decoderResult.setErrorsCorrected(correctedErrorsCount);
decoderResult.setErasures(erasures.length);
return decoderResult;
}
/**
* <p>Given data and error-correction codewords received, possibly corrupted by errors, attempts to
* correct the errors in-place.</p>
*
* @param codewords data and error correction codewords
* @param erasures positions of any known erasures
* @param numECCodewords number of error correction codewords that are available in codewords
* @throws ChecksumException if error correction fails
*/
private static correctErrors(codewords: Int32Array, erasures: Int32Array, numECCodewords: int): int {
if (erasures != null &&
erasures.length > numECCodewords / 2 + PDF417ScanningDecoder.MAX_ERRORS ||
numECCodewords < 0 ||
numECCodewords > PDF417ScanningDecoder.MAX_EC_CODEWORDS) {
// Too many errors or EC Codewords is corrupted
throw ChecksumException.getChecksumInstance();
}
return PDF417ScanningDecoder.errorCorrection.decode(codewords, numECCodewords, erasures);
}
/**
* Verify that all is OK with the codeword array.
* @throws FormatException
*/
private static verifyCodewordCount(codewords: Int32Array, numECCodewords: int): void {
if (codewords.length < 4) {
// Codeword array size should be at least 4 allowing for
// Count CW, At least one Data CW, Error Correction CW, Error Correction CW
throw FormatException.getFormatInstance();
}
// The first codeword, the Symbol Length Descriptor, shall always encode the total number of data
// codewords in the symbol, including the Symbol Length Descriptor itself, data codewords and pad
// codewords, but excluding the number of error correction codewords.
let numberOfCodewords: int = codewords[0];
if (numberOfCodewords > codewords.length) {
throw FormatException.getFormatInstance();
}
if (numberOfCodewords === 0) {
// Reset to the length of the array - 8 (Allow for at least level 3 Error Correction (8 Error Codewords)
if (numECCodewords < codewords.length) {
codewords[0] = codewords.length - numECCodewords;
} else {
throw FormatException.getFormatInstance();
}
}
}
private static getBitCountForCodeword(codeword: int): Int32Array {
let result: Int32Array = new Int32Array(8);
let previousValue: int = 0;
let i: int = result.length - 1;
while (true) {
if ((codeword & 0x1) !== previousValue) {
previousValue = codeword & 0x1;
i--;
if (i < 0) {
break;
}
}
result[i]++;
codeword >>= 1;
}
return result;
}
private static getCodewordBucketNumber(codeword: int | Int32Array): int {
if (codeword instanceof Int32Array) {
return this.getCodewordBucketNumber_Int32Array(codeword);
}
return this.getCodewordBucketNumber_number(codeword);
}
private static getCodewordBucketNumber_number(codeword: int): int {
return PDF417ScanningDecoder.getCodewordBucketNumber(PDF417ScanningDecoder.getBitCountForCodeword(codeword));
}
private static getCodewordBucketNumber_Int32Array(moduleBitCount: Int32Array): int {
return (moduleBitCount[0] - moduleBitCount[2] + moduleBitCount[4] - moduleBitCount[6] + 9) % 9;
}
public static toString(barcodeMatrix: BarcodeValue[][]): String {
let formatter = new Formatter();
// try (let formatter = new Formatter()) {
for (let row /*int*/ = 0; row < barcodeMatrix.length; row++) {
formatter.format('Row %2d: ', row);
for (let column /*int*/ = 0; column < barcodeMatrix[row].length; column++) {
let barcodeValue: BarcodeValue = barcodeMatrix[row][column];
if (barcodeValue.getValue().length === 0) {
formatter.format(' ', <Object[]>null);
} else {
formatter.format('%4d(%2d)', barcodeValue.getValue()[0],
barcodeValue.getConfidence(barcodeValue.getValue()[0]));
}
}
formatter.format('%n');
}
return formatter.toString();
// }
}
}