cpp/core/src/zxing/oned/OneDReader.cpp

   1 /*
   2  *  OneDReader.cpp
   3  *  ZXing
   4  *
   5  *  Created by Lukasz Warchol on 10-01-15.
   6  *  Copyright 2010 ZXing authors All rights reserved.
   7  *
   8  * Licensed under the Apache License, Version 2.0 (the "License");
   9  * you may not use this file except in compliance with the License.
  10  * You may obtain a copy of the License at
  11  *
  12  *      http://www.apache.org/licenses/LICENSE-2.0
  13  *
  14  * Unless required by applicable law or agreed to in writing, software
  15  * distributed under the License is distributed on an "AS IS" BASIS,
  16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  17  * See the License for the specific language governing permissions and
  18  * limitations under the License.
  19  */
  20
  21 #include "OneDReader.h"
  22 #include <zxing/ReaderException.h>
  23 #include <zxing/oned/OneDResultPoint.h>
  24 #include <math.h>
  25 #include <limits.h>
  26
  27 namespace zxing {
  28         namespace oned {
  29                 using namespace std;
  30
  31                 OneDReader::OneDReader() {
  32                 }
  33
  34                 Ref<Result> OneDReader::decode(Ref<BinaryBitmap> image, DecodeHints hints) {
  35
  36                   try {
  37                                 return doDecode(image, hints);
  38                         }catch (ReaderException re) {
  39                                 if (hints.getTryHarder() && image->isRotateSupported()) {
  40
  41                                         Ref<BinaryBitmap> rotatedImage(image->rotateCounterClockwise());
  42                                         Ref<Result> result(doDecode(rotatedImage, hints));
  43                                         /*
  44                                         // Record that we found it rotated 90 degrees CCW / 270 degrees CW
  45                                         Hashtable metadata = result.getResultMetadata();
  46                                         int orientation = 270;
  47                                         if (metadata != null && metadata.containsKey(ResultMetadataType.ORIENTATION)) {
  48                                                 // But if we found it reversed in doDecode(), add in that result here:
  49                                                 orientation = (orientation +
  50                                                                            ((Integer) metadata.get(ResultMetadataType.ORIENTATION)).intValue()) % 360;
  51                                         }
  52                                         result.putMetadata(ResultMetadataType.ORIENTATION, new Integer(orientation));
  53                                         */
  54           // Update result points
  55                                         std::vector<Ref<ResultPoint> > points (result->getResultPoints());
  56                                         int height = rotatedImage->getHeight();
  57                                         for (size_t i = 0; i < points.size(); i++) {
  58                                                 points[i].reset(new OneDResultPoint(height - points[i]->getY() - 1, points[i]->getX()));
  59                                         }
  60                                         return result;
  61                                 } else {
  62                                         throw re;
  63                                 }
  64                         }
  65                 }
  66
  67                 Ref<Result> OneDReader::doDecode(Ref<BinaryBitmap> image, DecodeHints hints){
  68                         int width = image->getWidth();
  69                         int height = image->getHeight();
  70                         Ref<BitArray> row(new BitArray(width));
  71                         int middle = height >> 1;
  72                         bool tryHarder = hints.getTryHarder();
  73                         int rowStep = (int)fmax(1, height >> (tryHarder ? 8 : 5));
  74                         int maxLines;
  75                         if (tryHarder) {
  76                                 maxLines = height; // Look at the whole image, not just the center
  77                         } else {
  78         maxLines = 15; // 15 rows spaced 1/32 apart is roughly the middle half of the image
  79                         }
  80
  81                         for (int x = 0; x < maxLines; x++) {
  82
  83                                 // Scanning from the middle out. Determine which row we're looking at next:
  84                                 int rowStepsAboveOrBelow = (x + 1) >> 1;
  85                                 bool isAbove = (x & 0x01) == 0; // i.e. is x even?
  86                                 int rowNumber = middle + rowStep * (isAbove ? rowStepsAboveOrBelow : -rowStepsAboveOrBelow);
  87                                 if (rowNumber < 0 || rowNumber >= height) {
  88                                         // Oops, if we run off the top or bottom, stop
  89                                         break;
  90                                 }
  91
  92                                 // Estimate black point for this row and load it:
  93                                 try {
  94                                         row = image->getBlackRow(rowNumber, row);
  95                                 }catch (ReaderException re) {
  96                                         continue;
  97                                 }catch (IllegalArgumentException re) {
  98           continue;
  99                                 }
 100
 101                                 // While we have the image data in a BitArray, it's fairly cheap to reverse it in place to
 102                                 // handle decoding upside down barcodes.
 103                                 for (int attempt = 0; attempt < 2; attempt++) {
 104                                         if (attempt == 1) { // trying again?
 105                                                 row->reverse(); // reverse the row and continue
 106                                         }
 107                                         try {
 108                                                 // Look for a barcode
 109                                                 Ref<Result> result = decodeRow(rowNumber, row);
 110                                                 // We found our barcode
 111                                                 if (attempt == 1) {
 112                                                         //                                              // But it was upside down, so note that
 113                                                         //                                              result.putMetadata(ResultMetadataType.ORIENTATION, new Integer(180));
 114                                                         //                                              // And remember to flip the result points horizontally.
 115                                                   std::vector<Ref<ResultPoint> > points(result->getResultPoints());
 116                                                   // if there's exactly two points (which there should be), flip the x coordinate
 117               // if there's not exactly 2, I don't know what do do with it
 118                                                   if (points.size() == 2) {
 119                 Ref<ResultPoint> pointZero(new OneDResultPoint(width - points[0]->getX() - 1, points[0]->getY()));
 120                 points[0] = pointZero;
 121
 122                 Ref<ResultPoint> pointOne(new OneDResultPoint(width - points[1]->getX() - 1, points[1]->getY()));
 123                 points[1] = pointOne;
 124
 125                 result.reset(new Result(result->getText(),result->getRawBytes(),points,result->getBarcodeFormat()));
 126                                                   }
 127                                                 }
 128                                                 return result;
 129                                         } catch (ReaderException re) {
 130                                                 // continue -- just couldn't decode this row
 131                                         }
 132                                 }
 133                         }
 134                         throw ReaderException("doDecode() failed");
 135                 }
 136
 137                 unsigned int OneDReader::patternMatchVariance(int counters[], int countersSize, const int pattern[], int maxIndividualVariance) {
 138                         int numCounters = countersSize;
 139                         unsigned int total = 0;
 140                         unsigned int patternLength = 0;
 141                         for (int i = 0; i < numCounters; i++) {
 142                                 total += counters[i];
 143                                 patternLength += pattern[i];
 144                         }
 145                         if (total < patternLength) {
 146                                 // If we don't even have one pixel per unit of bar width, assume this is too small
 147                                 // to reliably match, so fail:
 148                                 return INT_MAX;
 149                         }
 150                         // We're going to fake floating-point math in integers. We just need to use more bits.
 151                         // Scale up patternLength so that intermediate values below like scaledCounter will have
 152                         // more "significant digits"
 153                         unsigned int unitBarWidth = (total << INTEGER_MATH_SHIFT) / patternLength;
 154                         maxIndividualVariance = (maxIndividualVariance * unitBarWidth) >> INTEGER_MATH_SHIFT;
 155
 156                         unsigned int totalVariance = 0;
 157                         for (int x = 0; x < numCounters; x++) {
 158                                 int counter = counters[x] << INTEGER_MATH_SHIFT;
 159                                 int scaledPattern = pattern[x] * unitBarWidth;
 160                                 int variance = counter > scaledPattern ? counter - scaledPattern : scaledPattern - counter;
 161                                 if (variance > maxIndividualVariance) {
 162                                         return INT_MAX;
 163                                 }
 164                                 totalVariance += variance;
 165                         }
 166                         return totalVariance / total;
 167                 }
 168
 169                 void OneDReader::recordPattern(Ref<BitArray> row, int start, int counters[], int countersCount){
 170                         int numCounters = countersCount;//sizeof(counters) / sizeof(int);
 171                         for (int i = 0; i < numCounters; i++) {
 172                                 counters[i] = 0;
 173                         }
 174                         int end = row->getSize();
 175                         if (start >= end) {
 176                                 throw ReaderException("recordPattern: start >= end");
 177                         }
 178                         bool isWhite = !row->get(start);
 179                         int counterPosition = 0;
 180                         int i = start;
 181                         while (i < end) {
 182                                 bool pixel = row->get(i);
 183                                 if (pixel ^ isWhite) { // that is, exactly one is true
 184                                         counters[counterPosition]++;
 185                                 } else {
 186                                         counterPosition++;
 187                                         if (counterPosition == numCounters) {
 188                                                 break;
 189                                         } else {
 190                                                 counters[counterPosition] = 1;
 191                                                 isWhite ^= true; // isWhite = !isWhite;
 192                                         }
 193                                 }
 194                                 i++;
 195                         }
 196                         // If we read fully the last section of pixels and filled up our counters -- or filled
 197                         // the last counter but ran off the side of the image, OK. Otherwise, a problem.
 198                         if (!(counterPosition == numCounters || (counterPosition == numCounters - 1 && i == end))) {
 199                                 throw ReaderException("recordPattern");
 200                         }
 201                 }
 202
 203                 OneDReader::~OneDReader() {
 204                 }
 205         }
 206 }