--- /dev/null
+/*
+ * MonochromeRectangleDetector.cpp
+ * zxing
+ *
+ * Created by Luiz Silva on 09/02/2010.
+ * 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.
+ */
+\r
+#include <zxing/ReaderException.h>\r
+#include <zxing/datamatrix/detector/MonochromeRectangleDetector.h>\r
+#include <sstream>
+
+namespace zxing {
+namespace datamatrix {
+
+std::vector<Ref<CornerPoint> > MonochromeRectangleDetector::detect() {
+ int height = image_->getHeight();
+ int width = image_->getWidth();
+ int halfHeight = height >> 1;
+ int halfWidth = width >> 1;
+ int deltaY = max(1, height / (MAX_MODULES << 3));
+ int deltaX = max(1, width / (MAX_MODULES << 3));
+
+ int top = 0;
+ int bottom = height;
+ int left = 0;
+ int right = width;
+ Ref<CornerPoint> pointA(findCornerFromCenter(halfWidth, 0, left, right,
+ halfHeight, -deltaY, top, bottom, halfWidth >> 1));
+ top = (int) pointA->getY() - 1;
+ Ref<CornerPoint> pointB(findCornerFromCenter(halfWidth, -deltaX, left, right,
+ halfHeight, 0, top, bottom, halfHeight >> 1));
+ left = (int) pointB->getX() - 1;
+ Ref<CornerPoint> pointC(findCornerFromCenter(halfWidth, deltaX, left, right,
+ halfHeight, 0, top, bottom, halfHeight >> 1));
+ right = (int) pointC->getX() + 1;
+ Ref<CornerPoint> pointD(findCornerFromCenter(halfWidth, 0, left, right,
+ halfHeight, deltaY, top, bottom, halfWidth >> 1));
+ bottom = (int) pointD->getY() + 1;
+
+ // Go try to find point A again with better information -- might have been off at first.
+ pointA.reset(findCornerFromCenter(halfWidth, 0, left, right,
+ halfHeight, -deltaY, top, bottom, halfWidth >> 2));
+ std::vector<Ref<CornerPoint> > corners(4);\r
+ corners[0].reset(pointA);\r
+ corners[1].reset(pointB);\r
+ corners[2].reset(pointC);
+ corners[3].reset(pointD);
+ return corners;
+ }
+
+Ref<CornerPoint> MonochromeRectangleDetector::findCornerFromCenter(int centerX, int deltaX, int left, int right,
+ int centerY, int deltaY, int top, int bottom, int maxWhiteRun) {
+ int* lastRange = NULL;
+ for (int y = centerY, x = centerX;
+ y < bottom && y >= top && x < right && x >= left;
+ y += deltaY, x += deltaX) {
+ int* range;
+ if (deltaX == 0) {
+ // horizontal slices, up and down
+ range = blackWhiteRange(y, maxWhiteRun, left, right, true);
+ } else {
+ // vertical slices, left and right
+ range = blackWhiteRange(x, maxWhiteRun, top, bottom, false);
+ }
+ if (range == NULL) {
+ if (lastRange == NULL) {
+ throw ReaderException("Couldn't find corners (lastRange = NULL) ");
+ } else {
+ // lastRange was found
+ if (deltaX == 0) {
+ int lastY = y - deltaY;
+ if (lastRange[0] < centerX) {
+ if (lastRange[1] > centerX) {
+ // straddle, choose one or the other based on direction
+ Ref<CornerPoint> result(new CornerPoint(deltaY > 0 ? lastRange[0] : lastRange[1], lastY));
+ return result;
+ }
+ Ref<CornerPoint> result(new CornerPoint(lastRange[0], lastY));
+ return result;
+ } else {
+ Ref<CornerPoint> result(new CornerPoint(lastRange[1], lastY));
+ return result;
+ }
+ } else {
+ int lastX = x - deltaX;
+ if (lastRange[0] < centerY) {
+ if (lastRange[1] > centerY) {
+ Ref<CornerPoint> result(new CornerPoint(lastX, deltaX < 0 ? lastRange[0] : lastRange[1]));
+ return result;
+ }
+ Ref<CornerPoint> result(new CornerPoint(lastX, lastRange[0]));
+ return result;
+ } else {
+ Ref<CornerPoint> result(new CornerPoint(lastX, lastRange[1]));
+ return result;
+ }
+ }
+ }
+ }
+ lastRange = range;
+ }
+ throw ReaderException("Couldn't find corners");
+ }
+
+int* MonochromeRectangleDetector::blackWhiteRange(int fixedDimension, int maxWhiteRun, int minDim, int maxDim,
+ bool horizontal) {
+
+ int center = (minDim + maxDim) >> 1;
+
+ // Scan left/up first
+ int start = center;
+ while (start >= minDim) {
+ if (horizontal ? image_->get(start, fixedDimension) : image_->get(fixedDimension, start)) {
+ start--;
+ } else {
+ int whiteRunStart = start;
+ do {
+ start--;
+ } while (start >= minDim && !(horizontal ? image_->get(start, fixedDimension) :
+ image_->get(fixedDimension, start)));
+ int whiteRunSize = whiteRunStart - start;
+ if (start < minDim || whiteRunSize > maxWhiteRun) {
+ start = whiteRunStart;
+ break;
+ }
+ }
+ }
+ start++;
+
+ // Then try right/down
+ int end = center;
+ while (end < maxDim) {
+ if (horizontal ? image_->get(end, fixedDimension) : image_->get(fixedDimension, end)) {
+ end++;
+ } else {
+ int whiteRunStart = end;
+ do {
+ end++;
+ } while (end < maxDim && !(horizontal ? image_->get(end, fixedDimension) :
+ image_->get(fixedDimension, end)));
+ int whiteRunSize = end - whiteRunStart;
+ if (end >= maxDim || whiteRunSize > maxWhiteRun) {
+ end = whiteRunStart;
+ break;
+ }
+ }
+ }
+ end--;
+ int* result;
+ if (end > start) {
+ result = new int [2];
+ result[0] = start;
+ result[1] = end;
+ }
+ else
+ result = NULL;
+ return result;
+ }
+}
+}
projects / zxing.git / blobdiff