src/core/oned/Code128Reader.ts
/*
* 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.
*/
/*namespace com.google.zxing.oned {*/
import BarcodeFormat from '../BarcodeFormat';
import ChecksumException from '../ChecksumException';
// import BinaryBitmap from '../BinaryBitmap';
import BitArray from '../common/BitArray';
import DecodeHintType from '../DecodeHintType';
import FormatException from '../FormatException';
import NotFoundException from '../NotFoundException';
// import Reader from '../Reader';
import Result from '../Result';
// import ResultMetadataType from '../ResultMetadataType';
import ResultPoint from '../ResultPoint';
import OneDReader from './OneDReader';
/**
* <p>Decodes Code 128 barcodes.</p>
*
* @author Sean Owen
*/
export default class Code128Reader extends OneDReader {
private static CODE_PATTERNS: Int32Array[] = [
Int32Array.from([2, 1, 2, 2, 2, 2]),
Int32Array.from([2, 2, 2, 1, 2, 2]),
Int32Array.from([2, 2, 2, 2, 2, 1]),
Int32Array.from([1, 2, 1, 2, 2, 3]),
Int32Array.from([1, 2, 1, 3, 2, 2]),
Int32Array.from([1, 3, 1, 2, 2, 2]),
Int32Array.from([1, 2, 2, 2, 1, 3]),
Int32Array.from([1, 2, 2, 3, 1, 2]),
Int32Array.from([1, 3, 2, 2, 1, 2]),
Int32Array.from([2, 2, 1, 2, 1, 3]),
Int32Array.from([2, 2, 1, 3, 1, 2]),
Int32Array.from([2, 3, 1, 2, 1, 2]),
Int32Array.from([1, 1, 2, 2, 3, 2]),
Int32Array.from([1, 2, 2, 1, 3, 2]),
Int32Array.from([1, 2, 2, 2, 3, 1]),
Int32Array.from([1, 1, 3, 2, 2, 2]),
Int32Array.from([1, 2, 3, 1, 2, 2]),
Int32Array.from([1, 2, 3, 2, 2, 1]),
Int32Array.from([2, 2, 3, 2, 1, 1]),
Int32Array.from([2, 2, 1, 1, 3, 2]),
Int32Array.from([2, 2, 1, 2, 3, 1]),
Int32Array.from([2, 1, 3, 2, 1, 2]),
Int32Array.from([2, 2, 3, 1, 1, 2]),
Int32Array.from([3, 1, 2, 1, 3, 1]),
Int32Array.from([3, 1, 1, 2, 2, 2]),
Int32Array.from([3, 2, 1, 1, 2, 2]),
Int32Array.from([3, 2, 1, 2, 2, 1]),
Int32Array.from([3, 1, 2, 2, 1, 2]),
Int32Array.from([3, 2, 2, 1, 1, 2]),
Int32Array.from([3, 2, 2, 2, 1, 1]),
Int32Array.from([2, 1, 2, 1, 2, 3]),
Int32Array.from([2, 1, 2, 3, 2, 1]),
Int32Array.from([2, 3, 2, 1, 2, 1]),
Int32Array.from([1, 1, 1, 3, 2, 3]),
Int32Array.from([1, 3, 1, 1, 2, 3]),
Int32Array.from([1, 3, 1, 3, 2, 1]),
Int32Array.from([1, 1, 2, 3, 1, 3]),
Int32Array.from([1, 3, 2, 1, 1, 3]),
Int32Array.from([1, 3, 2, 3, 1, 1]),
Int32Array.from([2, 1, 1, 3, 1, 3]),
Int32Array.from([2, 3, 1, 1, 1, 3]),
Int32Array.from([2, 3, 1, 3, 1, 1]),
Int32Array.from([1, 1, 2, 1, 3, 3]),
Int32Array.from([1, 1, 2, 3, 3, 1]),
Int32Array.from([1, 3, 2, 1, 3, 1]),
Int32Array.from([1, 1, 3, 1, 2, 3]),
Int32Array.from([1, 1, 3, 3, 2, 1]),
Int32Array.from([1, 3, 3, 1, 2, 1]),
Int32Array.from([3, 1, 3, 1, 2, 1]),
Int32Array.from([2, 1, 1, 3, 3, 1]),
Int32Array.from([2, 3, 1, 1, 3, 1]),
Int32Array.from([2, 1, 3, 1, 1, 3]),
Int32Array.from([2, 1, 3, 3, 1, 1]),
Int32Array.from([2, 1, 3, 1, 3, 1]),
Int32Array.from([3, 1, 1, 1, 2, 3]),
Int32Array.from([3, 1, 1, 3, 2, 1]),
Int32Array.from([3, 3, 1, 1, 2, 1]),
Int32Array.from([3, 1, 2, 1, 1, 3]),
Int32Array.from([3, 1, 2, 3, 1, 1]),
Int32Array.from([3, 3, 2, 1, 1, 1]),
Int32Array.from([3, 1, 4, 1, 1, 1]),
Int32Array.from([2, 2, 1, 4, 1, 1]),
Int32Array.from([4, 3, 1, 1, 1, 1]),
Int32Array.from([1, 1, 1, 2, 2, 4]),
Int32Array.from([1, 1, 1, 4, 2, 2]),
Int32Array.from([1, 2, 1, 1, 2, 4]),
Int32Array.from([1, 2, 1, 4, 2, 1]),
Int32Array.from([1, 4, 1, 1, 2, 2]),
Int32Array.from([1, 4, 1, 2, 2, 1]),
Int32Array.from([1, 1, 2, 2, 1, 4]),
Int32Array.from([1, 1, 2, 4, 1, 2]),
Int32Array.from([1, 2, 2, 1, 1, 4]),
Int32Array.from([1, 2, 2, 4, 1, 1]),
Int32Array.from([1, 4, 2, 1, 1, 2]),
Int32Array.from([1, 4, 2, 2, 1, 1]),
Int32Array.from([2, 4, 1, 2, 1, 1]),
Int32Array.from([2, 2, 1, 1, 1, 4]),
Int32Array.from([4, 1, 3, 1, 1, 1]),
Int32Array.from([2, 4, 1, 1, 1, 2]),
Int32Array.from([1, 3, 4, 1, 1, 1]),
Int32Array.from([1, 1, 1, 2, 4, 2]),
Int32Array.from([1, 2, 1, 1, 4, 2]),
Int32Array.from([1, 2, 1, 2, 4, 1]),
Int32Array.from([1, 1, 4, 2, 1, 2]),
Int32Array.from([1, 2, 4, 1, 1, 2]),
Int32Array.from([1, 2, 4, 2, 1, 1]),
Int32Array.from([4, 1, 1, 2, 1, 2]),
Int32Array.from([4, 2, 1, 1, 1, 2]),
Int32Array.from([4, 2, 1, 2, 1, 1]),
Int32Array.from([2, 1, 2, 1, 4, 1]),
Int32Array.from([2, 1, 4, 1, 2, 1]),
Int32Array.from([4, 1, 2, 1, 2, 1]),
Int32Array.from([1, 1, 1, 1, 4, 3]),
Int32Array.from([1, 1, 1, 3, 4, 1]),
Int32Array.from([1, 3, 1, 1, 4, 1]),
Int32Array.from([1, 1, 4, 1, 1, 3]),
Int32Array.from([1, 1, 4, 3, 1, 1]),
Int32Array.from([4, 1, 1, 1, 1, 3]),
Int32Array.from([4, 1, 1, 3, 1, 1]),
Int32Array.from([1, 1, 3, 1, 4, 1]),
Int32Array.from([1, 1, 4, 1, 3, 1]),
Int32Array.from([3, 1, 1, 1, 4, 1]),
Int32Array.from([4, 1, 1, 1, 3, 1]),
Int32Array.from([2, 1, 1, 4, 1, 2]),
Int32Array.from([2, 1, 1, 2, 1, 4]),
Int32Array.from([2, 1, 1, 2, 3, 2]),
Int32Array.from([2, 3, 3, 1, 1, 1, 2]),
];
private static MAX_AVG_VARIANCE = 0.25;
private static MAX_INDIVIDUAL_VARIANCE = 0.7;
private static CODE_SHIFT = 98;
private static CODE_CODE_C = 99;
private static CODE_CODE_B = 100;
private static CODE_CODE_A = 101;
private static CODE_FNC_1 = 102;
private static CODE_FNC_2 = 97;
private static CODE_FNC_3 = 96;
private static CODE_FNC_4_A = 101;
private static CODE_FNC_4_B = 100;
private static CODE_START_A = 103;
private static CODE_START_B = 104;
private static CODE_START_C = 105;
private static CODE_STOP = 106;
private static findStartPattern(row: BitArray): Int32Array {
const width = row.getSize();
const rowOffset = row.getNextSet(0);
let counterPosition = 0;
let counters = Int32Array.from([0, 0, 0, 0, 0, 0]);
let patternStart = rowOffset;
let isWhite = false;
const patternLength = 6;
for (let i = rowOffset; i < width; i++) {
if (row.get(i) !== isWhite) {
counters[counterPosition]++;
} else {
if (counterPosition === (patternLength - 1)) {
let bestVariance = Code128Reader.MAX_AVG_VARIANCE;
let bestMatch = -1;
for (let startCode = Code128Reader.CODE_START_A; startCode <= Code128Reader.CODE_START_C; startCode++) {
const variance = OneDReader.patternMatchVariance(counters,
Code128Reader.CODE_PATTERNS[startCode], Code128Reader.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 Int32Array.from([patternStart, i, bestMatch]);
}
patternStart += counters[0] + counters[1];
counters = counters.slice(2, counters.length);
counters[counterPosition - 1] = 0;
counters[counterPosition] = 0;
counterPosition--;
} else {
counterPosition++;
}
counters[counterPosition] = 1;
isWhite = !isWhite;
}
}
throw new NotFoundException();
}
private static decodeCode(row: BitArray, counters: Int32Array, rowOffset: number): number {
OneDReader.recordPattern(row, rowOffset, counters);
let bestVariance = Code128Reader.MAX_AVG_VARIANCE; // worst variance we'll accept
let bestMatch = -1;
for (let d = 0; d < Code128Reader.CODE_PATTERNS.length; d++) {
const pattern = Code128Reader.CODE_PATTERNS[d];
const variance = this.patternMatchVariance(counters, pattern, Code128Reader.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 new NotFoundException();
}
}
public decodeRow(rowNumber: number, row: BitArray, hints?: Map<DecodeHintType, any>): Result {
const convertFNC1 = hints && (hints.get(DecodeHintType.ASSUME_GS1) === true);
const startPatternInfo = Code128Reader.findStartPattern(row);
const startCode = startPatternInfo[2];
let currentRawCodesIndex = 0;
const rawCodes: Uint8Array = new Uint8Array(20);
rawCodes[currentRawCodesIndex++] = startCode;
let codeSet;
switch (startCode) {
case Code128Reader.CODE_START_A:
codeSet = Code128Reader.CODE_CODE_A;
break;
case Code128Reader.CODE_START_B:
codeSet = Code128Reader.CODE_CODE_B;
break;
case Code128Reader.CODE_START_C:
codeSet = Code128Reader.CODE_CODE_C;
break;
default:
throw new FormatException();
}
let done = false;
let isNextShifted = false;
let result = '';
let lastStart = startPatternInfo[0];
let nextStart = startPatternInfo[1];
const counters: Int32Array = Int32Array.from([0, 0, 0, 0, 0, 0]);
let lastCode = 0;
let code = 0;
let checksumTotal = startCode;
let multiplier = 0;
let lastCharacterWasPrintable = true;
let upperMode = false;
let shiftUpperMode = false;
while (!done) {
const unshift = isNextShifted;
isNextShifted = false;
// Save off last code
lastCode = code;
// Decode another code from image
code = Code128Reader.decodeCode(row, counters, nextStart);
rawCodes[currentRawCodesIndex++] = code;
// Remember whether the last code was printable or not (excluding CODE_STOP)
if (code !== Code128Reader.CODE_STOP) {
lastCharacterWasPrintable = true;
}
// Add to checksum computation (if not CODE_STOP of course)
if (code !== Code128Reader.CODE_STOP) {
multiplier++;
checksumTotal += multiplier * code;
}
// Advance to where the next code will to start
lastStart = nextStart;
nextStart += counters.reduce((previous, current) => previous + current, 0);
// Take care of illegal start codes
switch (code) {
case Code128Reader.CODE_START_A:
case Code128Reader.CODE_START_B:
case Code128Reader.CODE_START_C:
throw new FormatException();
}
switch (codeSet) {
case Code128Reader.CODE_CODE_A:
if (code < 64) {
if (shiftUpperMode === upperMode) {
result += String.fromCharCode((' '.charCodeAt(0) + code));
} else {
result += String.fromCharCode((' '.charCodeAt(0) + code + 128));
}
shiftUpperMode = false;
} else if (code < 96) {
if (shiftUpperMode === upperMode) {
result += String.fromCharCode((code - 64));
} else {
result += String.fromCharCode((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 !== Code128Reader.CODE_STOP) {
lastCharacterWasPrintable = false;
}
switch (code) {
case Code128Reader.CODE_FNC_1:
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 += ']C1';
} else {
// GS1 specification 5.4.7.5. Every subsequent FNC1 is returned as ASCII 29 (GS)
result += String.fromCharCode(29);
}
}
break;
case Code128Reader.CODE_FNC_2:
case Code128Reader.CODE_FNC_3:
// do nothing?
break;
case Code128Reader.CODE_FNC_4_A:
if (!upperMode && shiftUpperMode) {
upperMode = true;
shiftUpperMode = false;
} else if (upperMode && shiftUpperMode) {
upperMode = false;
shiftUpperMode = false;
} else {
shiftUpperMode = true;
}
break;
case Code128Reader.CODE_SHIFT:
isNextShifted = true;
codeSet = Code128Reader.CODE_CODE_B;
break;
case Code128Reader.CODE_CODE_B:
codeSet = Code128Reader.CODE_CODE_B;
break;
case Code128Reader.CODE_CODE_C:
codeSet = Code128Reader.CODE_CODE_C;
break;
case Code128Reader.CODE_STOP:
done = true;
break;
}
}
break;
case Code128Reader.CODE_CODE_B:
if (code < 96) {
if (shiftUpperMode === upperMode) {
result += String.fromCharCode((' '.charCodeAt(0) + code));
} else {
result += String.fromCharCode((' '.charCodeAt(0) + code + 128));
}
shiftUpperMode = false;
} else {
if (code !== Code128Reader.CODE_STOP) {
lastCharacterWasPrintable = false;
}
switch (code) {
case Code128Reader.CODE_FNC_1:
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 += ']C1';
} else {
// GS1 specification 5.4.7.5. Every subsequent FNC1 is returned as ASCII 29 (GS)
result += String.fromCharCode(29);
}
}
break;
case Code128Reader.CODE_FNC_2:
case Code128Reader.CODE_FNC_3:
// do nothing?
break;
case Code128Reader.CODE_FNC_4_B:
if (!upperMode && shiftUpperMode) {
upperMode = true;
shiftUpperMode = false;
} else if (upperMode && shiftUpperMode) {
upperMode = false;
shiftUpperMode = false;
} else {
shiftUpperMode = true;
}
break;
case Code128Reader.CODE_SHIFT:
isNextShifted = true;
codeSet = Code128Reader.CODE_CODE_A;
break;
case Code128Reader.CODE_CODE_A:
codeSet = Code128Reader.CODE_CODE_A;
break;
case Code128Reader.CODE_CODE_C:
codeSet = Code128Reader.CODE_CODE_C;
break;
case Code128Reader.CODE_STOP:
done = true;
break;
}
}
break;
case Code128Reader.CODE_CODE_C:
if (code < 100) {
if (code < 10) {
result += '0';
}
result += code;
} else {
if (code !== Code128Reader.CODE_STOP) {
lastCharacterWasPrintable = false;
}
switch (code) {
case Code128Reader.CODE_FNC_1:
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 += ']C1';
} else {
// GS1 specification 5.4.7.5. Every subsequent FNC1 is returned as ASCII 29 (GS)
result += String.fromCharCode(29);
}
}
break;
case Code128Reader.CODE_CODE_A:
codeSet = Code128Reader.CODE_CODE_A;
break;
case Code128Reader.CODE_CODE_B:
codeSet = Code128Reader.CODE_CODE_B;
break;
case Code128Reader.CODE_STOP:
done = true;
break;
}
}
break;
}
// Unshift back to another code set if we were shifted
if (unshift) {
codeSet = codeSet === Code128Reader.CODE_CODE_A ? Code128Reader.CODE_CODE_B : Code128Reader.CODE_CODE_A;
}
}
const 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 new NotFoundException();
}
// Pull out from sum the value of the penultimate check code
checksumTotal -= multiplier * lastCode;
// lastCode is the checksum then:
if (checksumTotal % 103 !== lastCode) {
throw new ChecksumException();
}
// Need to pull out the check digits from string
const resultLength = result.length;
if (resultLength === 0) {
// false positive
throw new NotFoundException();
}
// 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 === Code128Reader.CODE_CODE_C) {
result = result.substring(0, resultLength - 2);
} else {
result = result.substring(0, resultLength - 1);
}
}
const left = (startPatternInfo[1] + startPatternInfo[0]) / 2.0;
const right = lastStart + lastPatternSize / 2.0;
const rawCodesSize = rawCodes.length;
const rawBytes: Uint8Array = new Uint8Array(rawCodesSize);
for (let i = 0; i < rawCodesSize; i++) {
rawBytes[i] = rawCodes[i];
}
const points: ResultPoint[] = [new ResultPoint(left, rowNumber), new ResultPoint(right, rowNumber)];
return new Result(result, rawBytes, 0, points, BarcodeFormat.CODE_128, new Date().getTime());
}
}