Moved character segmentation code to its own directory

src/openalpr/segmentation/verticalhistogram.cpp

@@ -0,0 +1,181 @@
+/*
+ * Copyright (c) 2013 New Designs Unlimited, LLC
+ * Opensource Automated License Plate Recognition [http://www.openalpr.com]
+ *
+ * This file is part of OpenAlpr.
+ *
+ * OpenAlpr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License
+ * version 3 as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "verticalhistogram.h"
+
+using namespace cv;
+using namespace std;
+
+VerticalHistogram::VerticalHistogram(Mat inputImage, Mat mask)
+{
+  analyzeImage(inputImage, mask);
+}
+
+VerticalHistogram::~VerticalHistogram()
+{
+  histoImg.release();
+  colHeights.clear();
+}
+
+void VerticalHistogram::analyzeImage(Mat inputImage, Mat mask)
+{
+  highestPeak = 0;
+  lowestValley = inputImage.rows;
+
+  histoImg = Mat::zeros(inputImage.size(), CV_8U);
+
+  int columnCount;
+
+  for (int col = 0; col < inputImage.cols; col++)
+  {
+    columnCount = 0;
+
+    for (int row = 0; row < inputImage.rows; row++)
+    {
+      if (inputImage.at<uchar>(row, col) > 0 && mask.at<uchar>(row, col) > 0)
+        columnCount++;
+    }
+
+    this->colHeights.push_back(columnCount);
+
+    if (columnCount < lowestValley)
+      lowestValley = columnCount;
+    if (columnCount > highestPeak)
+      highestPeak = columnCount;
+
+    for (; columnCount > 0; columnCount--)
+      histoImg.at<uchar>(inputImage.rows - columnCount, col) = 255;
+  }
+}
+
+int VerticalHistogram::getLocalMinimum(int leftX, int rightX)
+{
+  int minimum = histoImg.rows + 1;
+  int lowestX = leftX;
+
+  for (int i = leftX; i <= rightX; i++)
+  {
+    if (colHeights[i] < minimum)
+    {
+      lowestX = i;
+      minimum = colHeights[i];
+    }
+  }
+
+  return lowestX;
+}
+
+int VerticalHistogram::getLocalMaximum(int leftX, int rightX)
+{
+  int maximum = -1;
+  int highestX = leftX;
+
+  for (int i = leftX; i <= rightX; i++)
+  {
+    if (colHeights[i] > maximum)
+    {
+      highestX = i;
+      maximum = colHeights[i];
+    }
+  }
+
+  return highestX;
+}
+
+int VerticalHistogram::getHeightAt(int x)
+{
+  return colHeights[x];
+}
+
+void VerticalHistogram::findValleys()
+{
+  int MINIMUM_PEAK_HEIGHT = (int) (((float) highestPeak) * 0.75);
+
+  int totalWidth = colHeights.size();
+
+  int midpoint = ((highestPeak - lowestValley) / 2) + lowestValley;
+
+  HistogramDirection prevDirection = FALLING;
+
+  int relativePeakHeight = 0;
+  int valleyStart = 0;
+
+  for (int i = 0; i < totalWidth; i++)
+  {
+    bool aboveMidpoint = (colHeights[i] >= midpoint);
+
+    if (aboveMidpoint)
+    {
+      if (colHeights[i] > relativePeakHeight)
+        relativePeakHeight = colHeights[i];
+
+      prevDirection = FLAT;
+    }
+    else
+    {
+      relativePeakHeight = 0;
+
+      HistogramDirection direction = getHistogramDirection(i);
+
+      if ((prevDirection == FALLING || prevDirection == FLAT) && direction == RISING)
+      {
+      }
+      else if ((prevDirection == FALLING || prevDirection == FLAT) && direction == RISING)
+      {
+      }
+    }
+  }
+}
+
+HistogramDirection VerticalHistogram::getHistogramDirection(int index)
+{
+  int EXTRA_WIDTH_TO_AVERAGE = 2;
+
+  float trailingAverage = 0;
+  float forwardAverage = 0;
+
+  int trailStartIndex = index - EXTRA_WIDTH_TO_AVERAGE;
+  if (trailStartIndex < 0)
+    trailStartIndex = 0;
+  int forwardEndIndex = index + EXTRA_WIDTH_TO_AVERAGE;
+  if (forwardEndIndex >= colHeights.size())
+    forwardEndIndex = colHeights.size() - 1;
+
+  for (int i = index; i >= trailStartIndex; i--)
+  {
+    trailingAverage += colHeights[i];
+  }
+  trailingAverage = trailingAverage / ((float) (1 + index - trailStartIndex));
+
+  for (int i = index; i <= forwardEndIndex; i++)
+  {
+    forwardAverage += colHeights[i];
+  }
+  forwardAverage = forwardAverage / ((float) (1 + forwardEndIndex - index));
+
+  float diff = forwardAverage - trailingAverage;
+  float minDiff = ((float) (highestPeak - lowestValley)) * 0.10;
+
+  if (diff > minDiff)
+    return RISING;
+  else if (diff < minDiff)
+    return FALLING;
+  else
+    return FLAT;
+}