qzxing/source/zxing/oned/Code128Reader.cpp

491 lines
15 KiB
C++

// -*- mode:c++; tab-width:2; indent-tabs-mode:nil; c-basic-offset:2 -*-
/*
* Copyright 2010 ZXing authors All rights reserved.
*
* 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.
*/
#include "Code128Reader.h"
#include <zxing/oned/OneDResultPoint.h>
#include <zxing/common/Array.h>
#include <zxing/ReaderException.h>
#include <math.h>
#include <string.h>
#include <sstream>
namespace zxing {
namespace oned {
const int CODE_PATTERNS_LENGTH = 107;
const int countersLength = 6;
static const int CODE_PATTERNS[CODE_PATTERNS_LENGTH][countersLength] = {
{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}
};
Code128Reader::Code128Reader(){
}
int* Code128Reader::findStartPattern(Ref<BitArray> row){
int width = row->getSize();
int rowOffset = 0;
while (rowOffset < width) {
if (row->get(rowOffset)) {
break;
}
rowOffset++;
}
int counterPosition = 0;
int counters[countersLength] = {0,0,0,0,0,0};
int patternStart = rowOffset;
bool isWhite = false;
int patternLength = sizeof(counters) / sizeof(int);
for (int i = rowOffset; i < width; i++) {
bool pixel = row->get(i);
if (pixel ^ isWhite) {
counters[counterPosition]++;
} else {
if (counterPosition == patternLength - 1) {
unsigned int bestVariance = MAX_AVG_VARIANCE;
int bestMatch = -1;
for (int startCode = CODE_START_A; startCode <= CODE_START_C; startCode++) {
unsigned int variance = patternMatchVariance(counters, sizeof(counters) / sizeof(int),
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(std::max(0, patternStart - (i - patternStart) / 2), patternStart,
false)) {
int* resultValue = new int[3];
resultValue[0] = patternStart;
resultValue[1] = i;
resultValue[2] = bestMatch;
return resultValue;
}
}
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 ReaderException("");
}
int Code128Reader::decodeCode(Ref<BitArray> row, int counters[], int countersCount,
int rowOffset) {
if (!recordPattern(row, rowOffset, counters, countersCount)) {
throw ReaderException("");
}
unsigned int bestVariance = MAX_AVG_VARIANCE; // worst variance we'll accept
int bestMatch = -1;
for (int d = 0; d < CODE_PATTERNS_LENGTH; d++) {
int pattern[countersLength];
for(int ind = 0; ind< countersLength; ind++){
pattern[ind] = CODE_PATTERNS[d][ind];
}
// memcpy(pattern, CODE_PATTERNS[d], countersLength);
unsigned int variance = patternMatchVariance(counters, countersCount, 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 ReaderException("");
}
}
Ref<Result> Code128Reader::decodeRow(int rowNumber, Ref<BitArray> row) {
int* startPatternInfo = NULL;
try {
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 ReaderException("");
}
bool done = false;
bool isNextShifted = false;
std::string tmpResultString;
std::stringstream tmpResultSStr; // used if its Code 128C
int lastStart = startPatternInfo[0];
int nextStart = startPatternInfo[1];
int counters[countersLength] = {0,0,0,0,0,0};
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
try {
code = decodeCode(row, counters, sizeof(counters)/sizeof(int), nextStart);
} catch (ReaderException const& re) {
throw re;
}
// 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;
int _countersLength = sizeof(counters) / sizeof(int);
for (int i = 0; i < _countersLength; 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 ReaderException("");
}
switch (codeSet) {
case CODE_CODE_A:
if (code < 64) {
tmpResultString.append(1, (char) (' ' + code));
} else if (code < 96) {
tmpResultString.append(1, (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) {
tmpResultString.append(1, (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:
tmpResultSStr.str(std::string());
// the code read in this case is the number encoded directly
if (code < 100) {
if (code < 10) {
tmpResultSStr << '0';
}
tmpResultSStr << code;
tmpResultString.append(tmpResultSStr.str());
} 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 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:
int width = row->getSize();
while (nextStart < width && row->get(nextStart)) {
nextStart++;
}
if (!row->isRange(nextStart,
std::min(width, nextStart + (nextStart - lastStart) / 2),
false)) {
throw 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 ReaderException("");
}
// Need to pull out the check digits from string
int resultLength = tmpResultString.length();
// 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) {
tmpResultString.erase(resultLength - 2, resultLength);
} else {
tmpResultString.erase(resultLength - 1, resultLength);
}
}
Ref<String> resultString(new String(tmpResultString));
if (tmpResultString.length() == 0) {
// Almost surely a false positive
throw ReaderException("");
}
float left = (float) (startPatternInfo[1] + startPatternInfo[0]) / 2.0f;
float right = (float) (nextStart + lastStart) / 2.0f;
std::vector< Ref<ResultPoint> > resultPoints(2);
Ref<OneDResultPoint> resultPoint1(new OneDResultPoint(left, (float) rowNumber));
Ref<OneDResultPoint> resultPoint2(new OneDResultPoint(right, (float) rowNumber));
resultPoints[0] = resultPoint1;
resultPoints[1] = resultPoint2;
delete [] startPatternInfo;
ArrayRef<unsigned char> resultBytes(1);
return Ref<Result>(new Result(resultString, resultBytes, resultPoints,
BarcodeFormat_CODE_128));
} catch (ReaderException const& re) {
delete [] startPatternInfo;
return Ref<Result>();
}
}
void Code128Reader::append(char* s, char c){
int len = strlen(s);
s[len] = c;
s[len + 1] = '\0';
}
Code128Reader::~Code128Reader(){
}
}
}