/*
* 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
{
using System;
using System.Text;
using com.google.zxing.common;
public sealed class Code128Reader : AbstractOneDReader
{
private static int[][] CODE_PATTERNS = new int[][]{
new int[]{2, 1, 2, 2, 2, 2}, // 0
new int[]{2, 2, 2, 1, 2, 2},
new int[]{2, 2, 2, 2, 2, 1},
new int[]{1, 2, 1, 2, 2, 3},
new int[]{1, 2, 1, 3, 2, 2},
new int[]{1, 3, 1, 2, 2, 2}, // 5
new int[]{1, 2, 2, 2, 1, 3},
new int[]{1, 2, 2, 3, 1, 2},
new int[]{1, 3, 2, 2, 1, 2},
new int[]{2, 2, 1, 2, 1, 3},
new int[]{2, 2, 1, 3, 1, 2}, // 10
new int[]{2, 3, 1, 2, 1, 2},
new int[]{1, 1, 2, 2, 3, 2},
new int[]{1, 2, 2, 1, 3, 2},
new int[]{1, 2, 2, 2, 3, 1},
new int[]{1, 1, 3, 2, 2, 2}, // 15
new int[]{1, 2, 3, 1, 2, 2},
new int[]{1, 2, 3, 2, 2, 1},
new int[]{2, 2, 3, 2, 1, 1},
new int[]{2, 2, 1, 1, 3, 2},
new int[]{2, 2, 1, 2, 3, 1}, // 20
new int[]{2, 1, 3, 2, 1, 2},
new int[]{2, 2, 3, 1, 1, 2},
new int[]{3, 1, 2, 1, 3, 1},
new int[]{3, 1, 1, 2, 2, 2},
new int[]{3, 2, 1, 1, 2, 2}, // 25
new int[]{3, 2, 1, 2, 2, 1},
new int[]{3, 1, 2, 2, 1, 2},
new int[]{3, 2, 2, 1, 1, 2},
new int[]{3, 2, 2, 2, 1, 1},
new int[]{2, 1, 2, 1, 2, 3}, // 30
new int[]{2, 1, 2, 3, 2, 1},
new int[]{2, 3, 2, 1, 2, 1},
new int[]{1, 1, 1, 3, 2, 3},
new int[]{1, 3, 1, 1, 2, 3},
new int[]{1, 3, 1, 3, 2, 1}, // 35
new int[]{1, 1, 2, 3, 1, 3},
new int[]{1, 3, 2, 1, 1, 3},
new int[]{1, 3, 2, 3, 1, 1},
new int[]{2, 1, 1, 3, 1, 3},
new int[]{2, 3, 1, 1, 1, 3}, // 40
new int[]{2, 3, 1, 3, 1, 1},
new int[]{1, 1, 2, 1, 3, 3},
new int[]{1, 1, 2, 3, 3, 1},
new int[]{1, 3, 2, 1, 3, 1},
new int[]{1, 1, 3, 1, 2, 3}, // 45
new int[]{1, 1, 3, 3, 2, 1},
new int[]{1, 3, 3, 1, 2, 1},
new int[]{3, 1, 3, 1, 2, 1},
new int[]{2, 1, 1, 3, 3, 1},
new int[]{2, 3, 1, 1, 3, 1}, // 50
new int[]{2, 1, 3, 1, 1, 3},
new int[]{2, 1, 3, 3, 1, 1},
new int[]{2, 1, 3, 1, 3, 1},
new int[]{3, 1, 1, 1, 2, 3},
new int[]{3, 1, 1, 3, 2, 1}, // 55
new int[]{3, 3, 1, 1, 2, 1},
new int[]{3, 1, 2, 1, 1, 3},
new int[]{3, 1, 2, 3, 1, 1},
new int[]{3, 3, 2, 1, 1, 1},
new int[]{3, 1, 4, 1, 1, 1}, // 60
new int[]{2, 2, 1, 4, 1, 1},
new int[]{4, 3, 1, 1, 1, 1},
new int[]{1, 1, 1, 2, 2, 4},
new int[]{1, 1, 1, 4, 2, 2},
new int[] {1, 2, 1, 1, 2, 4}, // 65
new int[]{1, 2, 1, 4, 2, 1},
new int[]{1, 4, 1, 1, 2, 2},
new int[]{1, 4, 1, 2, 2, 1},
new int[]{1, 1, 2, 2, 1, 4},
new int[]{1, 1, 2, 4, 1, 2}, // 70
new int[]{1, 2, 2, 1, 1, 4},
new int[]{1, 2, 2, 4, 1, 1},
new int[]{1, 4, 2, 1, 1, 2},
new int[]{1, 4, 2, 2, 1, 1},
new int[]{2, 4, 1, 2, 1, 1}, // 75
new int[]{2, 2, 1, 1, 1, 4},
new int[]{4, 1, 3, 1, 1, 1},
new int[]{2, 4, 1, 1, 1, 2},
new int[]{1, 3, 4, 1, 1, 1},
new int[]{1, 1, 1, 2, 4, 2}, // 80
new int[]{1, 2, 1, 1, 4, 2},
new int[]{1, 2, 1, 2, 4, 1},
new int[]{1, 1, 4, 2, 1, 2},
new int[]{1, 2, 4, 1, 1, 2},
new int[]{1, 2, 4, 2, 1, 1}, // 85
new int[]{4, 1, 1, 2, 1, 2},
new int[]{4, 2, 1, 1, 1, 2},
new int[]{4, 2, 1, 2, 1, 1},
new int[]{2, 1, 2, 1, 4, 1},
new int[]{2, 1, 4, 1, 2, 1}, // 90
new int[]{4, 1, 2, 1, 2, 1},
new int[]{1, 1, 1, 1, 4, 3},
new int[]{1, 1, 1, 3, 4, 1},
new int[]{1, 3, 1, 1, 4, 1},
new int[]{1, 1, 4, 1, 1, 3}, // 95
new int[]{1, 1, 4, 3, 1, 1},
new int[]{4, 1, 1, 1, 1, 3},
new int[]{4, 1, 1, 3, 1, 1},
new int[]{1, 1, 3, 1, 4, 1},
new int[]{1, 1, 4, 1, 3, 1}, // 100
new int[]{3, 1, 1, 1, 4, 1},
new int[]{4, 1, 1, 1, 3, 1},
new int[]{2, 1, 1, 4, 1, 2},
new int[]{2, 1, 1, 2, 1, 4},
new int[]{2, 1, 1, 2, 3, 2}, // 105
new int[]{2, 3, 3, 1, 1, 1, 2}
};
private static int MAX_AVG_VARIANCE = (int) (PATTERN_MATCH_RESULT_SCALE_FACTOR * 0.25f);
private static int MAX_INDIVIDUAL_VARIANCE = (int) (PATTERN_MATCH_RESULT_SCALE_FACTOR * 0.7f);
private const int CODE_SHIFT = 98;
private const int CODE_CODE_C = 99;
private const int CODE_CODE_B = 100;
private const int CODE_CODE_A = 101;
private const int CODE_FNC_1 = 102;
private const int CODE_FNC_2 = 97;
private const int CODE_FNC_3 = 96;
private const int CODE_FNC_4_A = 101;
private const int CODE_FNC_4_B = 100;
private const int CODE_START_A = 103;
private const int CODE_START_B = 104;
private const int CODE_START_C = 105;
private const int CODE_STOP = 106;
private static int[] findStartPattern(BitArray row) {
int width = row.getSize();
int rowOffset = 0;
while (rowOffset < width) {
if (row.get(rowOffset)) {
break;
}
rowOffset++;
}
int counterPosition = 0;
int[] counters = new int[6];
int patternStart = rowOffset;
bool isWhite = false;
int patternLength = counters.Length;
for (int i = rowOffset; i < width; i++) {
bool pixel = row.get(i);
if ((!pixel && isWhite) || (pixel && !isWhite)) {
counters[counterPosition]++;
} else {
if (counterPosition == patternLength - 1) {
int bestVariance = MAX_AVG_VARIANCE;
int bestMatch = -1;
for (int startCode = CODE_START_A; startCode <= CODE_START_C; startCode++) {
int variance = patternMatchVariance(counters, CODE_PATTERNS[startCode], MAX_INDIVIDUAL_VARIANCE);
if (variance < bestVariance) {
bestVariance = variance;
bestMatch = startCode;
}
}
if (bestMatch >= 0) {
// Look for whitespace before start pattern, >= 50% of width of start pattern
if (row.isRange(Math.Max(0, patternStart - (i - patternStart) / 2), patternStart, false)) {
return new int[]{patternStart, i, bestMatch};
}
}
patternStart += counters[0] + counters[1];
for (int y = 2; y < patternLength; y++) {
counters[y - 2] = counters[y];
}
counters[patternLength - 2] = 0;
counters[patternLength - 1] = 0;
counterPosition--;
} else {
counterPosition++;
}
counters[counterPosition] = 1;
isWhite = !isWhite;
}
}
throw new ReaderException();
}
private static int decodeCode(BitArray row, int[] counters, int rowOffset) {
recordPattern(row, rowOffset, counters);
int 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];
int 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 new ReaderException();
}
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints) {
int[] startPatternInfo = findStartPattern(row);
int startCode = startPatternInfo[2];
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 new ReaderException();
}
bool done = false;
bool isNextShifted = false;
StringBuilder result = new StringBuilder();
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;
bool lastCharacterWasPrintable = true;
while (!done) {
bool unshift = isNextShifted;
isNextShifted = false;
// Save off last code
lastCode = code;
// Decode another code from image
code = decodeCode(row, counters, nextStart);
// 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 i = 0; i < counters.Length; i++) {
nextStart += counters[i];
}
// Take care of illegal start codes
switch (code) {
case CODE_START_A:
case CODE_START_B:
case CODE_START_C:
throw new ReaderException();
}
switch (codeSet) {
case CODE_CODE_A:
if (code < 64) {
result.Append((char) (' ' + code));
} else if (code < 96) {
result.Append((char) (code - 64));
} 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:
case CODE_FNC_2:
case CODE_FNC_3:
case CODE_FNC_4_A:
// do nothing?
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) {
result.Append((char) (' ' + code));
} else {
if (code != CODE_STOP) {
lastCharacterWasPrintable = false;
}
switch (code) {
case CODE_FNC_1:
case CODE_FNC_2:
case CODE_FNC_3:
case CODE_FNC_4_B:
// do nothing?
break;
case CODE_SHIFT:
isNextShifted = true;
codeSet = CODE_CODE_C;
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:
// do nothing?
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) {
switch (codeSet) {
case CODE_CODE_A:
codeSet = CODE_CODE_C;
break;
case CODE_CODE_B:
codeSet = CODE_CODE_A;
break;
case CODE_CODE_C:
codeSet = CODE_CODE_B;
break;
}
}
}
// Check for ample whitespice 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:
while (row.get(nextStart)) {
nextStart++;
}
if (!row.isRange(nextStart, Math.Min(row.getSize(), nextStart + (nextStart - lastStart) / 2), false)) {
throw new ReaderException();
}
// 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 ReaderException();
}
// Need to pull out the check digits from string
int resultLength = result.Length;
// Only bother if, well, 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.Remove(resultLength - 2, 2);
} else {
result.Remove(resultLength - 1, 1);
}
}
String resultString = result.ToString();
if (resultString.Length == 0) {
// Almost surely a false positive
throw new ReaderException();
}
float left = (float) (startPatternInfo[1] + startPatternInfo[0]) / 2.0f;
float right = (float) (nextStart + lastStart) / 2.0f;
return new Result(
resultString,
null,
new ResultPoint[]{
new GenericResultPoint(left, (float) rowNumber),
new GenericResultPoint(right, (float) rowNumber)},
BarcodeFormat.CODE_128);
}
}
}