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com.google.zxing.oned.rss.expanded.RSSExpandedReader Maven / Gradle / Ivy
/*
* Copyright (C) 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.
*/
/*
* These authors would like to acknowledge the Spanish Ministry of Industry,
* Tourism and Trade, for the support in the project TSI020301-2008-2
* "PIRAmIDE: Personalizable Interactions with Resources on AmI-enabled
* Mobile Dynamic Environments", led by Treelogic
* ( http://www.treelogic.com/ ):
*
* http://www.piramidepse.com/
*/
package com.google.zxing.oned.rss.expanded;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.DecodeHintType;
import com.google.zxing.FormatException;
import com.google.zxing.NotFoundException;
import com.google.zxing.Result;
import com.google.zxing.ResultPoint;
import com.google.zxing.common.BitArray;
import com.google.zxing.common.detector.MathUtils;
import com.google.zxing.oned.rss.AbstractRSSReader;
import com.google.zxing.oned.rss.DataCharacter;
import com.google.zxing.oned.rss.FinderPattern;
import com.google.zxing.oned.rss.RSSUtils;
import com.google.zxing.oned.rss.expanded.decoders.AbstractExpandedDecoder;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Collections;
/**
* @author Pablo Orduña, University of Deusto ([email protected] )
* @author Eduardo Castillejo, University of Deusto ([email protected] )
*/
public final class RSSExpandedReader extends AbstractRSSReader {
private static final int[] SYMBOL_WIDEST = {7, 5, 4, 3, 1};
private static final int[] EVEN_TOTAL_SUBSET = {4, 20, 52, 104, 204};
private static final int[] GSUM = {0, 348, 1388, 2948, 3988};
private static final int[][] FINDER_PATTERNS = {
{1,8,4,1}, // A
{3,6,4,1}, // B
{3,4,6,1}, // C
{3,2,8,1}, // D
{2,6,5,1}, // E
{2,2,9,1} // F
};
private static final int[][] WEIGHTS = {
{ 1, 3, 9, 27, 81, 32, 96, 77},
{ 20, 60, 180, 118, 143, 7, 21, 63},
{189, 145, 13, 39, 117, 140, 209, 205},
{193, 157, 49, 147, 19, 57, 171, 91},
{ 62, 186, 136, 197, 169, 85, 44, 132},
{185, 133, 188, 142, 4, 12, 36, 108},
{113, 128, 173, 97, 80, 29, 87, 50},
{150, 28, 84, 41, 123, 158, 52, 156},
{ 46, 138, 203, 187, 139, 206, 196, 166},
{ 76, 17, 51, 153, 37, 111, 122, 155},
{ 43, 129, 176, 106, 107, 110, 119, 146},
{ 16, 48, 144, 10, 30, 90, 59, 177},
{109, 116, 137, 200, 178, 112, 125, 164},
{ 70, 210, 208, 202, 184, 130, 179, 115},
{134, 191, 151, 31, 93, 68, 204, 190},
{148, 22, 66, 198, 172, 94, 71, 2},
{ 6, 18, 54, 162, 64, 192,154, 40},
{120, 149, 25, 75, 14, 42,126, 167},
{ 79, 26, 78, 23, 69, 207,199, 175},
{103, 98, 83, 38, 114, 131, 182, 124},
{161, 61, 183, 127, 170, 88, 53, 159},
{ 55, 165, 73, 8, 24, 72, 5, 15},
{ 45, 135, 194, 160, 58, 174, 100, 89}
};
private static final int FINDER_PAT_A = 0;
private static final int FINDER_PAT_B = 1;
private static final int FINDER_PAT_C = 2;
private static final int FINDER_PAT_D = 3;
private static final int FINDER_PAT_E = 4;
private static final int FINDER_PAT_F = 5;
private static final int[][] FINDER_PATTERN_SEQUENCES = {
{ FINDER_PAT_A, FINDER_PAT_A },
{ FINDER_PAT_A, FINDER_PAT_B, FINDER_PAT_B },
{ FINDER_PAT_A, FINDER_PAT_C, FINDER_PAT_B, FINDER_PAT_D },
{ FINDER_PAT_A, FINDER_PAT_E, FINDER_PAT_B, FINDER_PAT_D, FINDER_PAT_C },
{ FINDER_PAT_A, FINDER_PAT_E, FINDER_PAT_B, FINDER_PAT_D, FINDER_PAT_D, FINDER_PAT_F },
{ FINDER_PAT_A, FINDER_PAT_E, FINDER_PAT_B, FINDER_PAT_D, FINDER_PAT_E, FINDER_PAT_F, FINDER_PAT_F },
{ FINDER_PAT_A, FINDER_PAT_A, FINDER_PAT_B, FINDER_PAT_B, FINDER_PAT_C, FINDER_PAT_C, FINDER_PAT_D, FINDER_PAT_D },
{ FINDER_PAT_A, FINDER_PAT_A, FINDER_PAT_B, FINDER_PAT_B, FINDER_PAT_C, FINDER_PAT_C, FINDER_PAT_D, FINDER_PAT_E, FINDER_PAT_E },
{ FINDER_PAT_A, FINDER_PAT_A, FINDER_PAT_B, FINDER_PAT_B, FINDER_PAT_C, FINDER_PAT_C, FINDER_PAT_D, FINDER_PAT_E, FINDER_PAT_F, FINDER_PAT_F },
{ FINDER_PAT_A, FINDER_PAT_A, FINDER_PAT_B, FINDER_PAT_B, FINDER_PAT_C, FINDER_PAT_D, FINDER_PAT_D, FINDER_PAT_E, FINDER_PAT_E, FINDER_PAT_F, FINDER_PAT_F },
};
private static final int MAX_PAIRS = 11;
private final List pairs = new ArrayList<>(MAX_PAIRS);
private final List rows = new ArrayList<>();
private final int [] startEnd = new int[2];
private boolean startFromEven;
@Override
public Result decodeRow(int rowNumber,
BitArray row,
Map hints) throws NotFoundException, FormatException {
// Rows can start with even pattern in case in prev rows there where odd number of patters.
// So lets try twice
this.pairs.clear();
this.startFromEven = false;
try {
return constructResult(decodeRow2pairs(rowNumber, row));
} catch (NotFoundException e) {
// OK
}
this.pairs.clear();
this.startFromEven = true;
return constructResult(decodeRow2pairs(rowNumber, row));
}
@Override
public void reset() {
this.pairs.clear();
this.rows.clear();
}
// Not private for testing
List decodeRow2pairs(int rowNumber, BitArray row) throws NotFoundException {
boolean done = false;
while (!done) {
try {
this.pairs.add(retrieveNextPair(row, this.pairs, rowNumber));
} catch (NotFoundException nfe) {
if (this.pairs.isEmpty()) {
throw nfe;
}
// exit this loop when retrieveNextPair() fails and throws
done = true;
}
}
// TODO: verify sequence of finder patterns as in checkPairSequence()
if (checkChecksum()) {
return this.pairs;
}
boolean tryStackedDecode = !this.rows.isEmpty();
storeRow(rowNumber); // TODO: deal with reversed rows
if (tryStackedDecode) {
// When the image is 180-rotated, then rows are sorted in wrong direction.
// Try twice with both the directions.
List ps = checkRows(false);
if (ps != null) {
return ps;
}
ps = checkRows(true);
if (ps != null) {
return ps;
}
}
throw NotFoundException.getNotFoundInstance();
}
private List checkRows(boolean reverse) {
// Limit number of rows we are checking
// We use recursive algorithm with pure complexity and don't want it to take forever
// Stacked barcode can have up to 11 rows, so 25 seems reasonable enough
if (this.rows.size() > 25) {
this.rows.clear(); // We will never have a chance to get result, so clear it
return null;
}
this.pairs.clear();
if (reverse) {
Collections.reverse(this.rows);
}
List ps = null;
try {
ps = checkRows(new ArrayList<>(), 0);
} catch (NotFoundException e) {
// OK
}
if (reverse) {
Collections.reverse(this.rows);
}
return ps;
}
// Try to construct a valid rows sequence
// Recursion is used to implement backtracking
private List checkRows(List collectedRows, int currentRow) throws NotFoundException {
for (int i = currentRow; i < rows.size(); i++) {
ExpandedRow row = rows.get(i);
this.pairs.clear();
for (ExpandedRow collectedRow : collectedRows) {
this.pairs.addAll(collectedRow.getPairs());
}
this.pairs.addAll(row.getPairs());
if (isValidSequence(this.pairs)) {
if (checkChecksum()) {
return this.pairs;
}
List rs = new ArrayList<>(collectedRows);
rs.add(row);
try {
// Recursion: try to add more rows
return checkRows(rs, i + 1);
} catch (NotFoundException e) {
// We failed, try the next candidate
}
}
}
throw NotFoundException.getNotFoundInstance();
}
// Whether the pairs form a valid find pattern sequence,
// either complete or a prefix
private static boolean isValidSequence(List pairs) {
for (int[] sequence : FINDER_PATTERN_SEQUENCES) {
if (pairs.size() <= sequence.length) {
boolean stop = true;
for (int j = 0; j < pairs.size(); j++) {
if (pairs.get(j).getFinderPattern().getValue() != sequence[j]) {
stop = false;
break;
}
}
if (stop) {
return true;
}
}
}
return false;
}
private void storeRow(int rowNumber) {
// Discard if duplicate above or below; otherwise insert in order by row number.
int insertPos = 0;
boolean prevIsSame = false;
boolean nextIsSame = false;
while (insertPos < this.rows.size()) {
ExpandedRow erow = this.rows.get(insertPos);
if (erow.getRowNumber() > rowNumber) {
nextIsSame = erow.isEquivalent(this.pairs);
break;
}
prevIsSame = erow.isEquivalent(this.pairs);
insertPos++;
}
if (nextIsSame || prevIsSame) {
return;
}
// When the row was partially decoded (e.g. 2 pairs found instead of 3),
// it will prevent us from detecting the barcode.
// Try to merge partial rows
// Check whether the row is part of an already detected row
if (isPartialRow(this.pairs, this.rows)) {
return;
}
this.rows.add(insertPos, new ExpandedRow(this.pairs, rowNumber, false));
removePartialRows(this.pairs, this.rows);
}
// Remove all the rows that contains only specified pairs
private static void removePartialRows(Collection pairs, Collection rows) {
for (Iterator iterator = rows.iterator(); iterator.hasNext();) {
ExpandedRow r = iterator.next();
if (r.getPairs().size() != pairs.size()) {
boolean allFound = true;
for (ExpandedPair p : r.getPairs()) {
if (!pairs.contains(p)) {
allFound = false;
break;
}
}
if (allFound) {
// 'pairs' contains all the pairs from the row 'r'
iterator.remove();
}
}
}
}
// Returns true when one of the rows already contains all the pairs
private static boolean isPartialRow(Iterable pairs, Iterable rows) {
for (ExpandedRow r : rows) {
boolean allFound = true;
for (ExpandedPair p : pairs) {
boolean found = false;
for (ExpandedPair pp : r.getPairs()) {
if (p.equals(pp)) {
found = true;
break;
}
}
if (!found) {
allFound = false;
break;
}
}
if (allFound) {
// the row 'r' contain all the pairs from 'pairs'
return true;
}
}
return false;
}
// Only used for unit testing
List getRows() {
return this.rows;
}
// Not private for unit testing
static Result constructResult(List pairs) throws NotFoundException, FormatException {
BitArray binary = BitArrayBuilder.buildBitArray(pairs);
AbstractExpandedDecoder decoder = AbstractExpandedDecoder.createDecoder(binary);
String resultingString = decoder.parseInformation();
ResultPoint[] firstPoints = pairs.get(0).getFinderPattern().getResultPoints();
ResultPoint[] lastPoints = pairs.get(pairs.size() - 1).getFinderPattern().getResultPoints();
return new Result(
resultingString,
null,
new ResultPoint[]{firstPoints[0], firstPoints[1], lastPoints[0], lastPoints[1]},
BarcodeFormat.RSS_EXPANDED
);
}
private boolean checkChecksum() {
ExpandedPair firstPair = this.pairs.get(0);
DataCharacter checkCharacter = firstPair.getLeftChar();
DataCharacter firstCharacter = firstPair.getRightChar();
if (firstCharacter == null) {
return false;
}
int checksum = firstCharacter.getChecksumPortion();
int s = 2;
for (int i = 1; i < this.pairs.size(); ++i) {
ExpandedPair currentPair = this.pairs.get(i);
checksum += currentPair.getLeftChar().getChecksumPortion();
s++;
DataCharacter currentRightChar = currentPair.getRightChar();
if (currentRightChar != null) {
checksum += currentRightChar.getChecksumPortion();
s++;
}
}
checksum %= 211;
int checkCharacterValue = 211 * (s - 4) + checksum;
return checkCharacterValue == checkCharacter.getValue();
}
private static int getNextSecondBar(BitArray row, int initialPos) {
int currentPos;
if (row.get(initialPos)) {
currentPos = row.getNextUnset(initialPos);
currentPos = row.getNextSet(currentPos);
} else {
currentPos = row.getNextSet(initialPos);
currentPos = row.getNextUnset(currentPos);
}
return currentPos;
}
// not private for testing
ExpandedPair retrieveNextPair(BitArray row, List previousPairs, int rowNumber)
throws NotFoundException {
boolean isOddPattern = previousPairs.size() % 2 == 0;
if (startFromEven) {
isOddPattern = !isOddPattern;
}
FinderPattern pattern;
boolean keepFinding = true;
int forcedOffset = -1;
do {
this.findNextPair(row, previousPairs, forcedOffset);
pattern = parseFoundFinderPattern(row, rowNumber, isOddPattern);
if (pattern == null) {
forcedOffset = getNextSecondBar(row, this.startEnd[0]);
} else {
keepFinding = false;
}
} while (keepFinding);
// When stacked symbol is split over multiple rows, there's no way to guess if this pair can be last or not.
// boolean mayBeLast = checkPairSequence(previousPairs, pattern);
DataCharacter leftChar = this.decodeDataCharacter(row, pattern, isOddPattern, true);
if (!previousPairs.isEmpty() && previousPairs.get(previousPairs.size() - 1).mustBeLast()) {
throw NotFoundException.getNotFoundInstance();
}
DataCharacter rightChar;
try {
rightChar = this.decodeDataCharacter(row, pattern, isOddPattern, false);
} catch (NotFoundException ignored) {
rightChar = null;
}
return new ExpandedPair(leftChar, rightChar, pattern);
}
private void findNextPair(BitArray row, List previousPairs, int forcedOffset)
throws NotFoundException {
int[] counters = this.getDecodeFinderCounters();
counters[0] = 0;
counters[1] = 0;
counters[2] = 0;
counters[3] = 0;
int width = row.getSize();
int rowOffset;
if (forcedOffset >= 0) {
rowOffset = forcedOffset;
} else if (previousPairs.isEmpty()) {
rowOffset = 0;
} else {
ExpandedPair lastPair = previousPairs.get(previousPairs.size() - 1);
rowOffset = lastPair.getFinderPattern().getStartEnd()[1];
}
boolean searchingEvenPair = previousPairs.size() % 2 != 0;
if (startFromEven) {
searchingEvenPair = !searchingEvenPair;
}
boolean isWhite = false;
while (rowOffset < width) {
isWhite = !row.get(rowOffset);
if (!isWhite) {
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 (searchingEvenPair) {
reverseCounters(counters);
}
if (isFinderPattern(counters)) {
this.startEnd[0] = patternStart;
this.startEnd[1] = x;
return;
}
if (searchingEvenPair) {
reverseCounters(counters);
}
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 static void reverseCounters(int [] counters) {
int length = counters.length;
for (int i = 0; i < length / 2; ++i) {
int tmp = counters[i];
counters[i] = counters[length - i - 1];
counters[length - i - 1] = tmp;
}
}
private FinderPattern parseFoundFinderPattern(BitArray row, int rowNumber, boolean oddPattern) {
// Actually we found elements 2-5.
int firstCounter;
int start;
int end;
if (oddPattern) {
// If pattern number is odd, we need to locate element 1 *before* the current block.
int firstElementStart = this.startEnd[0] - 1;
// Locate element 1
while (firstElementStart >= 0 && !row.get(firstElementStart)) {
firstElementStart--;
}
firstElementStart++;
firstCounter = this.startEnd[0] - firstElementStart;
start = firstElementStart;
end = this.startEnd[1];
} else {
// If pattern number is even, the pattern is reversed, so we need to locate element 1 *after* the current block.
start = this.startEnd[0];
end = row.getNextUnset(this.startEnd[1] + 1);
firstCounter = end - this.startEnd[1];
}
// Make 'counters' hold 1-4
int [] counters = this.getDecodeFinderCounters();
System.arraycopy(counters, 0, counters, 1, counters.length - 1);
counters[0] = firstCounter;
int value;
try {
value = parseFinderValue(counters, FINDER_PATTERNS);
} catch (NotFoundException ignored) {
return null;
}
return new FinderPattern(value, new int[] {start, end}, start, end, rowNumber);
}
DataCharacter decodeDataCharacter(BitArray row,
FinderPattern pattern,
boolean isOddPattern,
boolean leftChar) throws NotFoundException {
int[] counters = this.getDataCharacterCounters();
Arrays.fill(counters, 0);
if (leftChar) {
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;
}
} //counters[] has the pixels of the module
int numModules = 17; //left and right data characters have all the same length
float elementWidth = MathUtils.sum(counters) / (float) numModules;
// Sanity check: element width for pattern and the character should match
float expectedElementWidth = (pattern.getStartEnd()[1] - pattern.getStartEnd()[0]) / 15.0f;
if (Math.abs(elementWidth - expectedElementWidth) / expectedElementWidth > 0.3f) {
throw NotFoundException.getNotFoundInstance();
}
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 = 1.0f * counters[i] / elementWidth;
int count = (int) (value + 0.5f); // Round
if (count < 1) {
if (value < 0.3f) {
throw NotFoundException.getNotFoundInstance();
}
count = 1;
} else if (count > 8) {
if (value > 8.7f) {
throw NotFoundException.getNotFoundInstance();
}
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(numModules);
int weightRowNumber = 4 * pattern.getValue() + (isOddPattern ? 0 : 2) + (leftChar ? 0 : 1) - 1;
int oddSum = 0;
int oddChecksumPortion = 0;
for (int i = oddCounts.length - 1; i >= 0; i--) {
if (isNotA1left(pattern, isOddPattern, leftChar)) {
int weight = WEIGHTS[weightRowNumber][2 * i];
oddChecksumPortion += oddCounts[i] * weight;
}
oddSum += oddCounts[i];
}
int evenChecksumPortion = 0;
for (int i = evenCounts.length - 1; i >= 0; i--) {
if (isNotA1left(pattern, isOddPattern, leftChar)) {
int weight = WEIGHTS[weightRowNumber][2 * i + 1];
evenChecksumPortion += evenCounts[i] * weight;
}
}
int checksumPortion = oddChecksumPortion + evenChecksumPortion;
if ((oddSum & 0x01) != 0 || oddSum > 13 || oddSum < 4) {
throw NotFoundException.getNotFoundInstance();
}
int group = (13 - oddSum) / 2;
int oddWidest = SYMBOL_WIDEST[group];
int evenWidest = 9 - oddWidest;
int vOdd = RSSUtils.getRSSvalue(oddCounts, oddWidest, true);
int vEven = RSSUtils.getRSSvalue(evenCounts, evenWidest, false);
int tEven = EVEN_TOTAL_SUBSET[group];
int gSum = GSUM[group];
int value = vOdd * tEven + vEven + gSum;
return new DataCharacter(value, checksumPortion);
}
private static boolean isNotA1left(FinderPattern pattern, boolean isOddPattern, boolean leftChar) {
// A1: pattern.getValue is 0 (A), and it's an oddPattern, and it is a left char
return !(pattern.getValue() == 0 && isOddPattern && leftChar);
}
private void adjustOddEvenCounts(int numModules) throws NotFoundException {
int oddSum = MathUtils.sum(this.getOddCounts());
int evenSum = MathUtils.sum(this.getEvenCounts());
boolean incrementOdd = false;
boolean decrementOdd = false;
if (oddSum > 13) {
decrementOdd = true;
} else if (oddSum < 4) {
incrementOdd = true;
}
boolean incrementEven = false;
boolean decrementEven = false;
if (evenSum > 13) {
decrementEven = true;
} else if (evenSum < 4) {
incrementEven = true;
}
int mismatch = oddSum + evenSum - numModules;
boolean oddParityBad = (oddSum & 0x01) == 1;
boolean evenParityBad = (evenSum & 0x01) == 0;
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(this.getOddCounts(), this.getOddRoundingErrors());
}
if (decrementOdd) {
decrement(this.getOddCounts(), this.getOddRoundingErrors());
}
if (incrementEven) {
if (decrementEven) {
throw NotFoundException.getNotFoundInstance();
}
increment(this.getEvenCounts(), this.getOddRoundingErrors());
}
if (decrementEven) {
decrement(this.getEvenCounts(), this.getEvenRoundingErrors());
}
}
}
