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Core barcode encoding/decoding library
/*
* Copyright 2009 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.oned.rss;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.DecodeHintType;
import com.google.zxing.NotFoundException;
import com.google.zxing.Result;
import com.google.zxing.ResultPoint;
import com.google.zxing.ResultPointCallback;
import com.google.zxing.common.BitArray;
import com.google.zxing.common.detector.MathUtils;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
/**
* Decodes RSS-14, including truncated and stacked variants. See ISO/IEC 24724:2006.
*/
public final class RSS14Reader extends AbstractRSSReader {
private static final int[] OUTSIDE_EVEN_TOTAL_SUBSET = {1,10,34,70,126};
private static final int[] INSIDE_ODD_TOTAL_SUBSET = {4,20,48,81};
private static final int[] OUTSIDE_GSUM = {0,161,961,2015,2715};
private static final int[] INSIDE_GSUM = {0,336,1036,1516};
private static final int[] OUTSIDE_ODD_WIDEST = {8,6,4,3,1};
private static final int[] INSIDE_ODD_WIDEST = {2,4,6,8};
private static final int[][] FINDER_PATTERNS = {
{3,8,2,1},
{3,5,5,1},
{3,3,7,1},
{3,1,9,1},
{2,7,4,1},
{2,5,6,1},
{2,3,8,1},
{1,5,7,1},
{1,3,9,1},
};
private final List possibleLeftPairs;
private final List possibleRightPairs;
public RSS14Reader() {
possibleLeftPairs = new ArrayList<>();
possibleRightPairs = new ArrayList<>();
}
@Override
public Result decodeRow(int rowNumber,
BitArray row,
Map hints) throws NotFoundException {
Pair leftPair = decodePair(row, false, rowNumber, hints);
addOrTally(possibleLeftPairs, leftPair);
row.reverse();
Pair rightPair = decodePair(row, true, rowNumber, hints);
addOrTally(possibleRightPairs, rightPair);
row.reverse();
for (Pair left : possibleLeftPairs) {
if (left.getCount() > 1) {
for (Pair right : possibleRightPairs) {
if (right.getCount() > 1 && checkChecksum(left, right)) {
return constructResult(left, right);
}
}
}
}
throw NotFoundException.getNotFoundInstance();
}
private static void addOrTally(Collection possiblePairs, Pair pair) {
if (pair == null) {
return;
}
boolean found = false;
for (Pair other : possiblePairs) {
if (other.getValue() == pair.getValue()) {
other.incrementCount();
found = true;
break;
}
}
if (!found) {
possiblePairs.add(pair);
}
}
@Override
public void reset() {
possibleLeftPairs.clear();
possibleRightPairs.clear();
}
private static Result constructResult(Pair leftPair, Pair rightPair) {
long symbolValue = 4537077L * leftPair.getValue() + rightPair.getValue();
String text = String.valueOf(symbolValue);
StringBuilder buffer = new StringBuilder(14);
for (int i = 13 - text.length(); i > 0; i--) {
buffer.append('0');
}
buffer.append(text);
int checkDigit = 0;
for (int i = 0; i < 13; i++) {
int digit = buffer.charAt(i) - '0';
checkDigit += (i & 0x01) == 0 ? 3 * digit : digit;
}
checkDigit = 10 - (checkDigit % 10);
if (checkDigit == 10) {
checkDigit = 0;
}
buffer.append(checkDigit);
ResultPoint[] leftPoints = leftPair.getFinderPattern().getResultPoints();
ResultPoint[] rightPoints = rightPair.getFinderPattern().getResultPoints();
return new Result(
buffer.toString(),
null,
new ResultPoint[] { leftPoints[0], leftPoints[1], rightPoints[0], rightPoints[1], },
BarcodeFormat.RSS_14);
}
private static boolean checkChecksum(Pair leftPair, Pair rightPair) {
//int leftFPValue = leftPair.getFinderPattern().getValue();
//int rightFPValue = rightPair.getFinderPattern().getValue();
//if ((leftFPValue == 0 && rightFPValue == 8) ||
// (leftFPValue == 8 && rightFPValue == 0)) {
//}
int checkValue = (leftPair.getChecksumPortion() + 16 * rightPair.getChecksumPortion()) % 79;
int targetCheckValue =
9 * leftPair.getFinderPattern().getValue() + rightPair.getFinderPattern().getValue();
if (targetCheckValue > 72) {
targetCheckValue--;
}
if (targetCheckValue > 8) {
targetCheckValue--;
}
return checkValue == targetCheckValue;
}
private Pair decodePair(BitArray row, boolean right, int rowNumber, Map hints) {
try {
int[] startEnd = findFinderPattern(row, right);
FinderPattern pattern = parseFoundFinderPattern(row, rowNumber, right, startEnd);
ResultPointCallback resultPointCallback = hints == null ? null :
(ResultPointCallback) hints.get(DecodeHintType.NEED_RESULT_POINT_CALLBACK);
if (resultPointCallback != null) {
startEnd = pattern.getStartEnd();
float center = (startEnd[0] + startEnd[1] - 1) / 2.0f;
if (right) {
// row is actually reversed
center = row.getSize() - 1 - center;
}
resultPointCallback.foundPossibleResultPoint(new ResultPoint(center, rowNumber));
}
DataCharacter outside = decodeDataCharacter(row, pattern, true);
DataCharacter inside = decodeDataCharacter(row, pattern, false);
return new Pair(1597 * outside.getValue() + inside.getValue(),
outside.getChecksumPortion() + 4 * inside.getChecksumPortion(),
pattern);
} catch (NotFoundException ignored) {
return null;
}
}
private DataCharacter decodeDataCharacter(BitArray row, FinderPattern pattern, boolean outsideChar)
throws NotFoundException {
int[] counters = getDataCharacterCounters();
Arrays.fill(counters, 0);
if (outsideChar) {
recordPatternInReverse(row, pattern.getStartEnd()[0], counters);
} else {
recordPattern(row, pattern.getStartEnd()[1], counters);
// reverse it
for (int i = 0, j = counters.length - 1; i < j; i++, j--) {
int temp = counters[i];
counters[i] = counters[j];
counters[j] = temp;
}
}
int numModules = outsideChar ? 16 : 15;
float elementWidth = MathUtils.sum(counters) / (float) numModules;
int[] oddCounts = this.getOddCounts();
int[] evenCounts = this.getEvenCounts();
float[] oddRoundingErrors = this.getOddRoundingErrors();
float[] evenRoundingErrors = this.getEvenRoundingErrors();
for (int i = 0; i < counters.length; i++) {
float value = counters[i] / elementWidth;
int count = (int) (value + 0.5f); // Round
if (count < 1) {
count = 1;
} else if (count > 8) {
count = 8;
}
int offset = i / 2;
if ((i & 0x01) == 0) {
oddCounts[offset] = count;
oddRoundingErrors[offset] = value - count;
} else {
evenCounts[offset] = count;
evenRoundingErrors[offset] = value - count;
}
}
adjustOddEvenCounts(outsideChar, numModules);
int oddSum = 0;
int oddChecksumPortion = 0;
for (int i = oddCounts.length - 1; i >= 0; i--) {
oddChecksumPortion *= 9;
oddChecksumPortion += oddCounts[i];
oddSum += oddCounts[i];
}
int evenChecksumPortion = 0;
int evenSum = 0;
for (int i = evenCounts.length - 1; i >= 0; i--) {
evenChecksumPortion *= 9;
evenChecksumPortion += evenCounts[i];
evenSum += evenCounts[i];
}
int checksumPortion = oddChecksumPortion + 3 * evenChecksumPortion;
if (outsideChar) {
if ((oddSum & 0x01) != 0 || oddSum > 12 || oddSum < 4) {
throw NotFoundException.getNotFoundInstance();
}
int group = (12 - oddSum) / 2;
int oddWidest = OUTSIDE_ODD_WIDEST[group];
int evenWidest = 9 - oddWidest;
int vOdd = RSSUtils.getRSSvalue(oddCounts, oddWidest, false);
int vEven = RSSUtils.getRSSvalue(evenCounts, evenWidest, true);
int tEven = OUTSIDE_EVEN_TOTAL_SUBSET[group];
int gSum = OUTSIDE_GSUM[group];
return new DataCharacter(vOdd * tEven + vEven + gSum, checksumPortion);
} else {
if ((evenSum & 0x01) != 0 || evenSum > 10 || evenSum < 4) {
throw NotFoundException.getNotFoundInstance();
}
int group = (10 - evenSum) / 2;
int oddWidest = INSIDE_ODD_WIDEST[group];
int evenWidest = 9 - oddWidest;
int vOdd = RSSUtils.getRSSvalue(oddCounts, oddWidest, true);
int vEven = RSSUtils.getRSSvalue(evenCounts, evenWidest, false);
int tOdd = INSIDE_ODD_TOTAL_SUBSET[group];
int gSum = INSIDE_GSUM[group];
return new DataCharacter(vEven * tOdd + vOdd + gSum, checksumPortion);
}
}
private int[] findFinderPattern(BitArray row, boolean rightFinderPattern)
throws NotFoundException {
int[] counters = getDecodeFinderCounters();
counters[0] = 0;
counters[1] = 0;
counters[2] = 0;
counters[3] = 0;
int width = row.getSize();
boolean isWhite = false;
int rowOffset = 0;
while (rowOffset < width) {
isWhite = !row.get(rowOffset);
if (rightFinderPattern == isWhite) {
// Will encounter white first when searching for right finder pattern
break;
}
rowOffset++;
}
int counterPosition = 0;
int patternStart = rowOffset;
for (int x = rowOffset; x < width; x++) {
if (row.get(x) != isWhite) {
counters[counterPosition]++;
} else {
if (counterPosition == 3) {
if (isFinderPattern(counters)) {
return new int[]{patternStart, x};
}
patternStart += counters[0] + counters[1];
counters[0] = counters[2];
counters[1] = counters[3];
counters[2] = 0;
counters[3] = 0;
counterPosition--;
} else {
counterPosition++;
}
counters[counterPosition] = 1;
isWhite = !isWhite;
}
}
throw NotFoundException.getNotFoundInstance();
}
private FinderPattern parseFoundFinderPattern(BitArray row, int rowNumber, boolean right, int[] startEnd)
throws NotFoundException {
// Actually we found elements 2-5
boolean firstIsBlack = row.get(startEnd[0]);
int firstElementStart = startEnd[0] - 1;
// Locate element 1
while (firstElementStart >= 0 && firstIsBlack != row.get(firstElementStart)) {
firstElementStart--;
}
firstElementStart++;
int firstCounter = startEnd[0] - firstElementStart;
// Make 'counters' hold 1-4
int[] counters = getDecodeFinderCounters();
System.arraycopy(counters, 0, counters, 1, counters.length - 1);
counters[0] = firstCounter;
int value = parseFinderValue(counters, FINDER_PATTERNS);
int start = firstElementStart;
int end = startEnd[1];
if (right) {
// row is actually reversed
start = row.getSize() - 1 - start;
end = row.getSize() - 1 - end;
}
return new FinderPattern(value, new int[] {firstElementStart, startEnd[1]}, start, end, rowNumber);
}
private void adjustOddEvenCounts(boolean outsideChar, int numModules) throws NotFoundException {
int oddSum = MathUtils.sum(getOddCounts());
int evenSum = MathUtils.sum(getEvenCounts());
boolean incrementOdd = false;
boolean decrementOdd = false;
boolean incrementEven = false;
boolean decrementEven = false;
if (outsideChar) {
if (oddSum > 12) {
decrementOdd = true;
} else if (oddSum < 4) {
incrementOdd = true;
}
if (evenSum > 12) {
decrementEven = true;
} else if (evenSum < 4) {
incrementEven = true;
}
} else {
if (oddSum > 11) {
decrementOdd = true;
} else if (oddSum < 5) {
incrementOdd = true;
}
if (evenSum > 10) {
decrementEven = true;
} else if (evenSum < 4) {
incrementEven = true;
}
}
int mismatch = oddSum + evenSum - numModules;
boolean oddParityBad = (oddSum & 0x01) == (outsideChar ? 1 : 0);
boolean evenParityBad = (evenSum & 0x01) == 1;
/*if (mismatch == 2) {
if (!(oddParityBad && evenParityBad)) {
throw ReaderException.getInstance();
}
decrementOdd = true;
decrementEven = true;
} else if (mismatch == -2) {
if (!(oddParityBad && evenParityBad)) {
throw ReaderException.getInstance();
}
incrementOdd = true;
incrementEven = true;
} else */
switch (mismatch) {
case 1:
if (oddParityBad) {
if (evenParityBad) {
throw NotFoundException.getNotFoundInstance();
}
decrementOdd = true;
} else {
if (!evenParityBad) {
throw NotFoundException.getNotFoundInstance();
}
decrementEven = true;
}
break;
case -1:
if (oddParityBad) {
if (evenParityBad) {
throw NotFoundException.getNotFoundInstance();
}
incrementOdd = true;
} else {
if (!evenParityBad) {
throw NotFoundException.getNotFoundInstance();
}
incrementEven = true;
}
break;
case 0:
if (oddParityBad) {
if (!evenParityBad) {
throw NotFoundException.getNotFoundInstance();
}
// Both bad
if (oddSum < evenSum) {
incrementOdd = true;
decrementEven = true;
} else {
decrementOdd = true;
incrementEven = true;
}
} else {
if (evenParityBad) {
throw NotFoundException.getNotFoundInstance();
}
// Nothing to do!
}
break;
default:
throw NotFoundException.getNotFoundInstance();
}
if (incrementOdd) {
if (decrementOdd) {
throw NotFoundException.getNotFoundInstance();
}
increment(getOddCounts(), getOddRoundingErrors());
}
if (decrementOdd) {
decrement(getOddCounts(), getOddRoundingErrors());
}
if (incrementEven) {
if (decrementEven) {
throw NotFoundException.getNotFoundInstance();
}
increment(getEvenCounts(), getOddRoundingErrors());
}
if (decrementEven) {
decrement(getEvenCounts(), getEvenRoundingErrors());
}
}
}
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