Moved image transformation (deskew) functions to its own class

src/openalpr/CMakeLists.txt

@@ -22,6 +22,7 @@ set(lpr_source_files
  edges/platelines.cpp
  edges/textlinecollection.cpp
  colorfilter.cpp
+ transformation.cpp
  textdetection/characteranalysis.cpp
  textdetection/platemask.cpp
  textdetection/textcontours.cpp

src/openalpr/licenseplatecandidate.cpp

@@ -20,6 +20,8 @@
 #include <opencv2/core/core.hpp>
 
 #include "licenseplatecandidate.h"
+#include "edges/edgefinder.h"
+#include "transformation.h"
 
 using namespace std;
 using namespace cv;
@@ -65,6 +67,8 @@ void LicensePlateCandidate::recognize()
     PlateCorners cornerFinder(pipeline_data->crop_gray, &plateLines, pipeline_data);
     vector<Point> smallPlateCorners = cornerFinder.findPlateCorners();
 
+    EdgeFinder edgeFinder(pipeline_data);
+    
     if (cornerFinder.confidence > 0)
     {
 
@@ -74,11 +78,16 @@ void LicensePlateCandidate::recognize()
 
       Mat originalCrop = pipeline_data->crop_gray;
       
-      pipeline_data->plate_corners = transformPointsToOriginalImage(this->pipeline_data->grayImg, pipeline_data->crop_gray, expandedRegion, smallPlateCorners);
+      Transformation imgTransform(this->pipeline_data->grayImg, pipeline_data->crop_gray, expandedRegion);
+      pipeline_data->plate_corners = imgTransform.transformSmallPointsToBigImage(smallPlateCorners);
       
-      Size outputImageSize = getOutputImageSize(pipeline_data->plate_corners);
-      Mat transmtx = getTransformationMatrix(pipeline_data->plate_corners, outputImageSize);
-      pipeline_data->crop_gray = deSkewPlate(this->pipeline_data->grayImg, outputImageSize, transmtx);
+      Size cropSize = getCropSize(pipeline_data->plate_corners);
+      Mat transmtx = imgTransform.getTransformationMatrix(pipeline_data->plate_corners, cropSize);
+      pipeline_data->crop_gray = imgTransform.crop(cropSize, transmtx);
+      
+
+      if (this->config->debugGeneral)
+        displayImage(config, "quadrilateral", pipeline_data->crop_gray);
 
 
       
@@ -87,16 +96,14 @@ void LicensePlateCandidate::recognize()
       vector<TextLine> newLines;
       for (uint i = 0; i < pipeline_data->textLines.size(); i++)
       {        
-        vector<Point2f> textArea = transformPointsToOriginalImage(this->pipeline_data->grayImg, originalCrop, expandedRegion, 
-                pipeline_data->textLines[i].textArea);
-        vector<Point2f> linePolygon = transformPointsToOriginalImage(this->pipeline_data->grayImg, originalCrop, expandedRegion, 
-                pipeline_data->textLines[i].linePolygon);
+        vector<Point2f> textArea = imgTransform.transformSmallPointsToBigImage(pipeline_data->textLines[i].textArea);
+        vector<Point2f> linePolygon = imgTransform.transformSmallPointsToBigImage(pipeline_data->textLines[i].linePolygon);
         
         vector<Point2f> textAreaRemapped;
         vector<Point2f> linePolygonRemapped;
         
-        perspectiveTransform(textArea, textAreaRemapped, transmtx);
-        perspectiveTransform(linePolygon, linePolygonRemapped, transmtx);
+        textAreaRemapped = imgTransform.remapSmallPointstoCrop(textArea, transmtx);
+        linePolygonRemapped = imgTransform.remapSmallPointstoCrop(linePolygon, transmtx);
         
         newLines.push_back(TextLine(textAreaRemapped, linePolygonRemapped));
       }
@@ -123,31 +130,13 @@ void LicensePlateCandidate::recognize()
   }
 }
 
-// Re-maps the coordinates from the smallImage to the coordinate space of the bigImage.
-vector<Point2f> LicensePlateCandidate::transformPointsToOriginalImage(Mat bigImage, Mat smallImage, Rect region, vector<Point> corners)
-{
-  vector<Point2f> cornerPoints;
-  for (uint i = 0; i < corners.size(); i++)
-  {
-    float bigX = (corners[i].x * ((float) region.width / smallImage.cols));
-    float bigY = (corners[i].y * ((float) region.height / smallImage.rows));
-
-    bigX = bigX + region.x;
-    bigY = bigY + region.y;
-
-    cornerPoints.push_back(Point2f(bigX, bigY));
-  }
-
-  return cornerPoints;
-}
-
-Size LicensePlateCandidate::getOutputImageSize(vector<Point2f> corners)
+Size LicensePlateCandidate::getCropSize(vector<Point2f> areaCorners)
 {
   // Figure out the approximate width/height of the license plate region, so we can maintain the aspect ratio.
-  LineSegment leftEdge(round(corners[3].x), round(corners[3].y), round(corners[0].x), round(corners[0].y));
-  LineSegment rightEdge(round(corners[2].x), round(corners[2].y), round(corners[1].x), round(corners[1].y));
-  LineSegment topEdge(round(corners[0].x), round(corners[0].y), round(corners[1].x), round(corners[1].y));
-  LineSegment bottomEdge(round(corners[3].x), round(corners[3].y), round(corners[2].x), round(corners[2].y));
+  LineSegment leftEdge(round(areaCorners[3].x), round(areaCorners[3].y), round(areaCorners[0].x), round(areaCorners[0].y));
+  LineSegment rightEdge(round(areaCorners[2].x), round(areaCorners[2].y), round(areaCorners[1].x), round(areaCorners[1].y));
+  LineSegment topEdge(round(areaCorners[0].x), round(areaCorners[0].y), round(areaCorners[1].x), round(areaCorners[1].y));
+  LineSegment bottomEdge(round(areaCorners[3].x), round(areaCorners[3].y), round(areaCorners[2].x), round(areaCorners[2].y));
 
   float w = distanceBetweenPoints(leftEdge.midpoint(), rightEdge.midpoint());
   float h = distanceBetweenPoints(bottomEdge.midpoint(), topEdge.midpoint());
@@ -163,37 +152,3 @@ Size LicensePlateCandidate::getOutputImageSize(vector<Point2f> corners)
   return Size(width, height);
 }
 
-Mat LicensePlateCandidate::getTransformationMatrix(vector<Point2f> corners, Size outputImageSize)
-{
-  // Corners of the destination image
-  vector<Point2f> quad_pts;
-  quad_pts.push_back(Point2f(0, 0));
-  quad_pts.push_back(Point2f(outputImageSize.width, 0));
-  quad_pts.push_back(Point2f(outputImageSize.width, outputImageSize.height));
-  quad_pts.push_back(Point2f(0, outputImageSize.height));
-
-  // Get transformation matrix
-  Mat transmtx = getPerspectiveTransform(corners, quad_pts);
-
-  return transmtx;
-}
-
-Mat LicensePlateCandidate::deSkewPlate(Mat inputImage, Size outputImageSize, Mat transformationMatrix)
-{
-  
-  
-  Mat deskewed(outputImageSize, this->pipeline_data->grayImg.type());
-  
-  // Apply perspective transformation to the image
-  warpPerspective(inputImage, deskewed, transformationMatrix, deskewed.size(), INTER_CUBIC);
-
-  
-  
-  if (this->config->debugGeneral)
-    displayImage(config, "quadrilateral", deskewed);
-
-  return deskewed;
-}
-
-
-

src/openalpr/licenseplatecandidate.h

@@ -30,6 +30,7 @@
 #include "utility.h"
 #include "constants.h"
 #include "edges/platelines.h"
+#include "transformation.h"
 #include "textdetection/characteranalysis.h"
 #include "segmentation/charactersegmenter.h"
 #include "edges/platecorners.h"
@@ -59,10 +60,7 @@ class LicensePlateCandidate
     cv::Mat filterByCharacterHue(std::vector<std::vector<cv::Point> > charRegionContours);
     std::vector<cv::Point> findPlateCorners(cv::Mat inputImage, PlateLines plateLines, CharacterAnalysis textAnalysis);	// top-left, top-right, bottom-right, bottom-left
 
-    cv::Size getOutputImageSize(std::vector<cv::Point2f> corners);
-    std::vector<cv::Point2f> transformPointsToOriginalImage(cv::Mat bigImage, cv::Mat smallImage, cv::Rect region, std::vector<cv::Point> corners);
-    cv::Mat getTransformationMatrix(std::vector<cv::Point2f> corners, cv::Size outputImageSize);
-    cv::Mat deSkewPlate(cv::Mat inputImage, cv::Size outputImageSize, cv::Mat transformationMatrix);
+    cv::Size getCropSize(std::vector<cv::Point2f> areaCorners);
     
 };
 

src/openalpr/transformation.cpp

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2014 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 "transformation.h"
+
+using namespace std;
+using namespace cv;
+
+Transformation::Transformation(Mat bigImage, Mat smallImage, Rect regionInBigImage) {
+  this->bigImage = bigImage;
+  this->smallImage = smallImage;
+  this->regionInBigImage = regionInBigImage;
+}
+
+
+Transformation::~Transformation() {
+}
+
+// Re-maps the coordinates from the smallImage to the coordinate space of the bigImage.
+vector<Point2f> Transformation::transformSmallPointsToBigImage(vector<Point> points)
+{
+  vector<Point2f> bigPoints;
+  for (uint i = 0; i < points.size(); i++)
+  {
+    float bigX = (points[i].x * ((float) regionInBigImage.width / smallImage.cols));
+    float bigY = (points[i].y * ((float) regionInBigImage.height / smallImage.rows));
+
+    bigX = bigX + regionInBigImage.x;
+    bigY = bigY + regionInBigImage.y;
+
+    bigPoints.push_back(Point2f(bigX, bigY));
+  }
+
+  return bigPoints;
+}
+
+
+Mat Transformation::getTransformationMatrix(vector<Point2f> corners, Size outputImageSize)
+{
+  // Corners of the destination image
+  vector<Point2f> quad_pts;
+  quad_pts.push_back(Point2f(0, 0));
+  quad_pts.push_back(Point2f(outputImageSize.width, 0));
+  quad_pts.push_back(Point2f(outputImageSize.width, outputImageSize.height));
+  quad_pts.push_back(Point2f(0, outputImageSize.height));
+
+  // Get transformation matrix
+  Mat transmtx = getPerspectiveTransform(corners, quad_pts);
+
+  return transmtx;
+}
+
+Mat Transformation::crop(Size outputImageSize, Mat transformationMatrix)
+{
+  
+  
+  Mat deskewed(outputImageSize, this->bigImage.type());
+  
+  // Apply perspective transformation to the image
+  warpPerspective(this->bigImage, deskewed, transformationMatrix, deskewed.size(), INTER_CUBIC);
+
+  
+  
+
+  return deskewed;
+}
+
+vector<Point2f> Transformation::remapSmallPointstoCrop(vector<Point2f> smallPoints, cv::Mat transformationMatrix)
+{
+  vector<Point2f> remappedPoints;
+  perspectiveTransform(smallPoints, remappedPoints, transformationMatrix);
+  
+  return remappedPoints;
+}
+        

src/openalpr/transformation.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2014 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/>.
+*/
+
+#ifndef OPENALPR_TRANSFORMATION_H
+#define	OPENALPR_TRANSFORMATION_H
+
+#include "opencv2/imgproc/imgproc.hpp"
+
+class Transformation {
+public:
+  Transformation(cv::Mat bigImage, cv::Mat smallImage, cv::Rect regionInBigImage);
+  virtual ~Transformation();
+  
+  std::vector<cv::Point2f> transformSmallPointsToBigImage(std::vector<cv::Point> points);
+  
+  cv::Mat getTransformationMatrix(std::vector<cv::Point2f> corners, cv::Size outputImageSize);
+  
+  cv::Mat crop(cv::Size outputImageSize, cv::Mat transformationMatrix);
+  std::vector<cv::Point2f> remapSmallPointstoCrop(std::vector<cv::Point2f> smallPoints, cv::Mat transformationMatrix);
+  
+  
+private:
+  cv::Mat bigImage;
+  cv::Mat smallImage;
+  cv::Rect regionInBigImage;
+  
+};
+
+#endif	/* OPENALPR_TRANSFORMATION_H */
+