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