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/*
 * Copyright 2008 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;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.ChecksumException;
import com.google.zxing.DecodeHintType;
import com.google.zxing.FormatException;
import com.google.zxing.NotFoundException;
import com.google.zxing.Result;
import com.google.zxing.ResultMetadataType;
import com.google.zxing.ResultPoint;
import com.google.zxing.common.BitArray;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * 

Decodes Code 128 barcodes.

* * @author Sean Owen */ public final class Code128Reader extends OneDReader { static final int[][] CODE_PATTERNS = { {2, 1, 2, 2, 2, 2}, // 0 {2, 2, 2, 1, 2, 2}, {2, 2, 2, 2, 2, 1}, {1, 2, 1, 2, 2, 3}, {1, 2, 1, 3, 2, 2}, {1, 3, 1, 2, 2, 2}, // 5 {1, 2, 2, 2, 1, 3}, {1, 2, 2, 3, 1, 2}, {1, 3, 2, 2, 1, 2}, {2, 2, 1, 2, 1, 3}, {2, 2, 1, 3, 1, 2}, // 10 {2, 3, 1, 2, 1, 2}, {1, 1, 2, 2, 3, 2}, {1, 2, 2, 1, 3, 2}, {1, 2, 2, 2, 3, 1}, {1, 1, 3, 2, 2, 2}, // 15 {1, 2, 3, 1, 2, 2}, {1, 2, 3, 2, 2, 1}, {2, 2, 3, 2, 1, 1}, {2, 2, 1, 1, 3, 2}, {2, 2, 1, 2, 3, 1}, // 20 {2, 1, 3, 2, 1, 2}, {2, 2, 3, 1, 1, 2}, {3, 1, 2, 1, 3, 1}, {3, 1, 1, 2, 2, 2}, {3, 2, 1, 1, 2, 2}, // 25 {3, 2, 1, 2, 2, 1}, {3, 1, 2, 2, 1, 2}, {3, 2, 2, 1, 1, 2}, {3, 2, 2, 2, 1, 1}, {2, 1, 2, 1, 2, 3}, // 30 {2, 1, 2, 3, 2, 1}, {2, 3, 2, 1, 2, 1}, {1, 1, 1, 3, 2, 3}, {1, 3, 1, 1, 2, 3}, {1, 3, 1, 3, 2, 1}, // 35 {1, 1, 2, 3, 1, 3}, {1, 3, 2, 1, 1, 3}, {1, 3, 2, 3, 1, 1}, {2, 1, 1, 3, 1, 3}, {2, 3, 1, 1, 1, 3}, // 40 {2, 3, 1, 3, 1, 1}, {1, 1, 2, 1, 3, 3}, {1, 1, 2, 3, 3, 1}, {1, 3, 2, 1, 3, 1}, {1, 1, 3, 1, 2, 3}, // 45 {1, 1, 3, 3, 2, 1}, {1, 3, 3, 1, 2, 1}, {3, 1, 3, 1, 2, 1}, {2, 1, 1, 3, 3, 1}, {2, 3, 1, 1, 3, 1}, // 50 {2, 1, 3, 1, 1, 3}, {2, 1, 3, 3, 1, 1}, {2, 1, 3, 1, 3, 1}, {3, 1, 1, 1, 2, 3}, {3, 1, 1, 3, 2, 1}, // 55 {3, 3, 1, 1, 2, 1}, {3, 1, 2, 1, 1, 3}, {3, 1, 2, 3, 1, 1}, {3, 3, 2, 1, 1, 1}, {3, 1, 4, 1, 1, 1}, // 60 {2, 2, 1, 4, 1, 1}, {4, 3, 1, 1, 1, 1}, {1, 1, 1, 2, 2, 4}, {1, 1, 1, 4, 2, 2}, {1, 2, 1, 1, 2, 4}, // 65 {1, 2, 1, 4, 2, 1}, {1, 4, 1, 1, 2, 2}, {1, 4, 1, 2, 2, 1}, {1, 1, 2, 2, 1, 4}, {1, 1, 2, 4, 1, 2}, // 70 {1, 2, 2, 1, 1, 4}, {1, 2, 2, 4, 1, 1}, {1, 4, 2, 1, 1, 2}, {1, 4, 2, 2, 1, 1}, {2, 4, 1, 2, 1, 1}, // 75 {2, 2, 1, 1, 1, 4}, {4, 1, 3, 1, 1, 1}, {2, 4, 1, 1, 1, 2}, {1, 3, 4, 1, 1, 1}, {1, 1, 1, 2, 4, 2}, // 80 {1, 2, 1, 1, 4, 2}, {1, 2, 1, 2, 4, 1}, {1, 1, 4, 2, 1, 2}, {1, 2, 4, 1, 1, 2}, {1, 2, 4, 2, 1, 1}, // 85 {4, 1, 1, 2, 1, 2}, {4, 2, 1, 1, 1, 2}, {4, 2, 1, 2, 1, 1}, {2, 1, 2, 1, 4, 1}, {2, 1, 4, 1, 2, 1}, // 90 {4, 1, 2, 1, 2, 1}, {1, 1, 1, 1, 4, 3}, {1, 1, 1, 3, 4, 1}, {1, 3, 1, 1, 4, 1}, {1, 1, 4, 1, 1, 3}, // 95 {1, 1, 4, 3, 1, 1}, {4, 1, 1, 1, 1, 3}, {4, 1, 1, 3, 1, 1}, {1, 1, 3, 1, 4, 1}, {1, 1, 4, 1, 3, 1}, // 100 {3, 1, 1, 1, 4, 1}, {4, 1, 1, 1, 3, 1}, {2, 1, 1, 4, 1, 2}, {2, 1, 1, 2, 1, 4}, {2, 1, 1, 2, 3, 2}, // 105 {2, 3, 3, 1, 1, 1, 2} }; private static final float MAX_AVG_VARIANCE = 0.25f; private static final float MAX_INDIVIDUAL_VARIANCE = 0.7f; private static final int CODE_SHIFT = 98; private static final int CODE_CODE_C = 99; private static final int CODE_CODE_B = 100; private static final int CODE_CODE_A = 101; private static final int CODE_FNC_1 = 102; private static final int CODE_FNC_2 = 97; private static final int CODE_FNC_3 = 96; private static final int CODE_FNC_4_A = 101; private static final int CODE_FNC_4_B = 100; private static final int CODE_START_A = 103; private static final int CODE_START_B = 104; private static final int CODE_START_C = 105; private static final int CODE_STOP = 106; private static int[] findStartPattern(BitArray row) throws NotFoundException { int width = row.getSize(); int rowOffset = row.getNextSet(0); int counterPosition = 0; int[] counters = new int[6]; int patternStart = rowOffset; boolean isWhite = false; int patternLength = counters.length; for (int i = rowOffset; i < width; i++) { if (row.get(i) != isWhite) { counters[counterPosition]++; } else { if (counterPosition == patternLength - 1) { float bestVariance = MAX_AVG_VARIANCE; int bestMatch = -1; for (int startCode = CODE_START_A; startCode <= CODE_START_C; startCode++) { float variance = patternMatchVariance(counters, CODE_PATTERNS[startCode], MAX_INDIVIDUAL_VARIANCE); if (variance < bestVariance) { bestVariance = variance; bestMatch = startCode; } } // Look for whitespace before start pattern, >= 50% of width of start pattern if (bestMatch >= 0 && row.isRange(Math.max(0, patternStart - (i - patternStart) / 2), patternStart, false)) { return new int[]{patternStart, i, bestMatch}; } patternStart += counters[0] + counters[1]; System.arraycopy(counters, 2, counters, 0, counterPosition - 1); counters[counterPosition - 1] = 0; counters[counterPosition] = 0; counterPosition--; } else { counterPosition++; } counters[counterPosition] = 1; isWhite = !isWhite; } } throw NotFoundException.getNotFoundInstance(); } private static int decodeCode(BitArray row, int[] counters, int rowOffset) throws NotFoundException { recordPattern(row, rowOffset, counters); float bestVariance = MAX_AVG_VARIANCE; // worst variance we'll accept int bestMatch = -1; for (int d = 0; d < CODE_PATTERNS.length; d++) { int[] pattern = CODE_PATTERNS[d]; float variance = patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE); if (variance < bestVariance) { bestVariance = variance; bestMatch = d; } } // TODO We're overlooking the fact that the STOP pattern has 7 values, not 6. if (bestMatch >= 0) { return bestMatch; } else { throw NotFoundException.getNotFoundInstance(); } } @Override public Result decodeRow(int rowNumber, BitArray row, Map hints) throws NotFoundException, FormatException, ChecksumException { boolean convertFNC1 = hints != null && hints.containsKey(DecodeHintType.ASSUME_GS1); int symbologyModifier = 0; int[] startPatternInfo = findStartPattern(row); int startCode = startPatternInfo[2]; List rawCodes = new ArrayList<>(20); rawCodes.add((byte) startCode); int codeSet; switch (startCode) { case CODE_START_A: codeSet = CODE_CODE_A; break; case CODE_START_B: codeSet = CODE_CODE_B; break; case CODE_START_C: codeSet = CODE_CODE_C; break; default: throw FormatException.getFormatInstance(); } boolean done = false; boolean isNextShifted = false; StringBuilder result = new StringBuilder(20); int lastStart = startPatternInfo[0]; int nextStart = startPatternInfo[1]; int[] counters = new int[6]; int lastCode = 0; int code = 0; int checksumTotal = startCode; int multiplier = 0; boolean lastCharacterWasPrintable = true; boolean upperMode = false; boolean shiftUpperMode = false; while (!done) { boolean unshift = isNextShifted; isNextShifted = false; // Save off last code lastCode = code; // Decode another code from image code = decodeCode(row, counters, nextStart); rawCodes.add((byte) code); // Remember whether the last code was printable or not (excluding CODE_STOP) if (code != CODE_STOP) { lastCharacterWasPrintable = true; } // Add to checksum computation (if not CODE_STOP of course) if (code != CODE_STOP) { multiplier++; checksumTotal += multiplier * code; } // Advance to where the next code will to start lastStart = nextStart; for (int counter : counters) { nextStart += counter; } // Take care of illegal start codes switch (code) { case CODE_START_A: case CODE_START_B: case CODE_START_C: throw FormatException.getFormatInstance(); } switch (codeSet) { case CODE_CODE_A: if (code < 64) { if (shiftUpperMode == upperMode) { result.append((char) (' ' + code)); } else { result.append((char) (' ' + code + 128)); } shiftUpperMode = false; } else if (code < 96) { if (shiftUpperMode == upperMode) { result.append((char) (code - 64)); } else { result.append((char) (code + 64)); } shiftUpperMode = false; } else { // Don't let CODE_STOP, which always appears, affect whether whether we think the last // code was printable or not. if (code != CODE_STOP) { lastCharacterWasPrintable = false; } switch (code) { case CODE_FNC_1: if (result.length() == 0) { // FNC1 at first or second character determines the symbology symbologyModifier = 1; } else if (result.length() == 1) { symbologyModifier = 2; } if (convertFNC1) { if (result.length() == 0) { // GS1 specification 5.4.3.7. and 5.4.6.4. If the first char after the start code // is FNC1 then this is GS1-128. We add the symbology identifier. result.append("]C1"); } else { // GS1 specification 5.4.7.5. Every subsequent FNC1 is returned as ASCII 29 (GS) result.append((char) 29); } } break; case CODE_FNC_2: symbologyModifier = 4; break; case CODE_FNC_3: // do nothing? break; case CODE_FNC_4_A: if (!upperMode && shiftUpperMode) { upperMode = true; shiftUpperMode = false; } else if (upperMode && shiftUpperMode) { upperMode = false; shiftUpperMode = false; } else { shiftUpperMode = true; } break; case CODE_SHIFT: isNextShifted = true; codeSet = CODE_CODE_B; break; case CODE_CODE_B: codeSet = CODE_CODE_B; break; case CODE_CODE_C: codeSet = CODE_CODE_C; break; case CODE_STOP: done = true; break; } } break; case CODE_CODE_B: if (code < 96) { if (shiftUpperMode == upperMode) { result.append((char) (' ' + code)); } else { result.append((char) (' ' + code + 128)); } shiftUpperMode = false; } else { if (code != CODE_STOP) { lastCharacterWasPrintable = false; } switch (code) { case CODE_FNC_1: if (result.length() == 0) { // FNC1 at first or second character determines the symbology symbologyModifier = 1; } else if (result.length() == 1) { symbologyModifier = 2; } if (convertFNC1) { if (result.length() == 0) { // GS1 specification 5.4.3.7. and 5.4.6.4. If the first char after the start code // is FNC1 then this is GS1-128. We add the symbology identifier. result.append("]C1"); } else { // GS1 specification 5.4.7.5. Every subsequent FNC1 is returned as ASCII 29 (GS) result.append((char) 29); } } break; case CODE_FNC_2: symbologyModifier = 4; break; case CODE_FNC_3: // do nothing? break; case CODE_FNC_4_B: if (!upperMode && shiftUpperMode) { upperMode = true; shiftUpperMode = false; } else if (upperMode && shiftUpperMode) { upperMode = false; shiftUpperMode = false; } else { shiftUpperMode = true; } break; case CODE_SHIFT: isNextShifted = true; codeSet = CODE_CODE_A; break; case CODE_CODE_A: codeSet = CODE_CODE_A; break; case CODE_CODE_C: codeSet = CODE_CODE_C; break; case CODE_STOP: done = true; break; } } break; case CODE_CODE_C: if (code < 100) { if (code < 10) { result.append('0'); } result.append(code); } else { if (code != CODE_STOP) { lastCharacterWasPrintable = false; } switch (code) { case CODE_FNC_1: if (result.length() == 0) { // FNC1 at first or second character determines the symbology symbologyModifier = 1; } else if (result.length() == 1) { symbologyModifier = 2; } if (convertFNC1) { if (result.length() == 0) { // GS1 specification 5.4.3.7. and 5.4.6.4. If the first char after the start code // is FNC1 then this is GS1-128. We add the symbology identifier. result.append("]C1"); } else { // GS1 specification 5.4.7.5. Every subsequent FNC1 is returned as ASCII 29 (GS) result.append((char) 29); } } break; case CODE_CODE_A: codeSet = CODE_CODE_A; break; case CODE_CODE_B: codeSet = CODE_CODE_B; break; case CODE_STOP: done = true; break; } } break; } // Unshift back to another code set if we were shifted if (unshift) { codeSet = codeSet == CODE_CODE_A ? CODE_CODE_B : CODE_CODE_A; } } int lastPatternSize = nextStart - lastStart; // Check for ample whitespace following pattern, but, to do this we first need to remember that // we fudged decoding CODE_STOP since it actually has 7 bars, not 6. There is a black bar left // to read off. Would be slightly better to properly read. Here we just skip it: nextStart = row.getNextUnset(nextStart); if (!row.isRange(nextStart, Math.min(row.getSize(), nextStart + (nextStart - lastStart) / 2), false)) { throw NotFoundException.getNotFoundInstance(); } // Pull out from sum the value of the penultimate check code checksumTotal -= multiplier * lastCode; // lastCode is the checksum then: if (checksumTotal % 103 != lastCode) { throw ChecksumException.getChecksumInstance(); } // Need to pull out the check digits from string int resultLength = result.length(); if (resultLength == 0) { // false positive throw NotFoundException.getNotFoundInstance(); } // Only bother if the result had at least one character, and if the checksum digit happened to // be a printable character. If it was just interpreted as a control code, nothing to remove. if (resultLength > 0 && lastCharacterWasPrintable) { if (codeSet == CODE_CODE_C) { result.delete(resultLength - 2, resultLength); } else { result.delete(resultLength - 1, resultLength); } } float left = (startPatternInfo[1] + startPatternInfo[0]) / 2.0f; float right = lastStart + lastPatternSize / 2.0f; int rawCodesSize = rawCodes.size(); byte[] rawBytes = new byte[rawCodesSize]; for (int i = 0; i < rawCodesSize; i++) { rawBytes[i] = rawCodes.get(i); } Result resultObject = new Result( result.toString(), rawBytes, new ResultPoint[]{ new ResultPoint(left, rowNumber), new ResultPoint(right, rowNumber)}, BarcodeFormat.CODE_128); resultObject.putMetadata(ResultMetadataType.SYMBOLOGY_IDENTIFIER, "]C" + symbologyModifier); return resultObject; } }




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