Added support for OpenCL GPU acceleration

config/openalpr.conf.in

@@ -36,9 +36,10 @@ max_detection_input_width = 1280
 max_detection_input_height = 720
 
 ; detector is the technique used to find license plate regions in an image.  Value can be set to
-; lbpcpu   - default LBP-based detector uses the system CPU  
-; lbpgpu  - LBP-based detector that uses Nvidia GPU to increase recognition speed.
-; morphcpu - Experimental detector that detects white rectangles in an image.  Does not require training.
+; lbpcpu    - default LBP-based detector uses the system CPU  
+; lbpgpu    - LBP-based detector that uses Nvidia GPU to increase recognition speed.
+; lbpopencl - LBP-based detector that uses OpenCL GPU to increase recognition speed.  Requires OpenCV 3.0
+; morphcpu  - Experimental detector that detects white rectangles in an image.  Does not require training.
 detector = lbpcpu
 
 ; Bypasses plate detection.  If this is set to 1, the library assumes that each region provided is a likely plate area.

src/openalpr/CMakeLists.txt

@@ -8,6 +8,7 @@ set(lpr_source_files
  detection/detector.cpp
  detection/detectorcpu.cpp
  detection/detectorcuda.cpp
+ detection/detectorocl.cpp
  detection/detectorfactory.cpp
  detection/detectormorph.cpp
  licenseplatecandidate.cpp

src/openalpr/config.cpp

@@ -158,6 +158,8 @@ namespace alpr
       detector = DETECTOR_LBP_CPU;
     else if (detectorString.compare("lbpgpu") == 0)
       detector = DETECTOR_LBP_GPU;
+    else if (detectorString.compare("lbpopencl") == 0)
+      detector = DETECTOR_LBP_OPENCL;
     else if (detectorString.compare("morphcpu") == 0)
       detector = DETECTOR_MORPH_CPU;
     else

src/openalpr/config.h

@@ -146,7 +146,8 @@ namespace alpr
   {
     DETECTOR_LBP_CPU=0,
     DETECTOR_LBP_GPU=1,
-    DETECTOR_MORPH_CPU=2
+    DETECTOR_MORPH_CPU=2,
+    DETECTOR_LBP_OPENCL=3
   };
 
 }

src/openalpr/detection/detectorfactory.cpp

@@ -1,5 +1,6 @@
 #include "detectorfactory.h"
 #include "detectormorph.h"
+#include "detectorocl.h"
 
 namespace alpr
 {
@@ -21,6 +22,15 @@ namespace alpr
 	  return new DetectorCPU(config);
       #endif
     }
+    else if (config->detector == DETECTOR_LBP_OPENCL)
+    {
+      #if OPENCV_MAJOR_VERSION == 3
+      return new DetectorOCL(config);
+      #else
+      std::cerr << "Error: OpenCL acceleration requires OpenCV 3.0.  " << std::endl;
+      return new DetectorCPU(config);
+      #endif
+    }
     else if (config->detector == DETECTOR_MORPH_CPU)
     {
       return new DetectorMorph(config);

src/openalpr/detection/detectorocl.cpp

@@ -0,0 +1,153 @@
+/*
+ * Copyright (c) 2015 OpenALPR Technology, Inc.
+ * Open source 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 "detectorocl.h"
+
+#if OPENCV_MAJOR_VERSION == 3
+
+using namespace cv;
+using namespace std;
+
+namespace alpr
+{
+
+
+  DetectorOCL::DetectorOCL(Config* config) : Detector(config) {
+
+    cv::ocl::setUseOpenCL(true);
+
+
+
+
+    if (!ocl::haveOpenCL())
+    {
+      this->loaded = false;
+      cerr << "OpenCL not detected" << endl;
+    }
+    else if( this->plate_cascade.load( config->getCascadeRuntimeDir() + config->country + ".xml" ) )
+    {
+      this->loaded = true;
+    }
+    else
+    {
+      this->loaded = false;
+      printf("--(!)Error loading CPU classifier\n");
+    }
+  }
+
+
+  DetectorOCL::~DetectorOCL() {
+  }
+
+  vector<PlateRegion> DetectorOCL::detect(Mat frame, std::vector<cv::Rect> regionsOfInterest)
+  {
+
+    Mat frame_gray;
+
+    if (frame.channels() > 2)
+    {
+      cvtColor( frame, frame_gray, CV_BGR2GRAY );
+    }
+    else
+    {
+      frame.copyTo(frame_gray);
+    }
+
+
+    vector<PlateRegion> detectedRegions;
+    for (int i = 0; i < regionsOfInterest.size(); i++)
+    {
+      // Sanity check.  If roi width or height is less than minimum possible plate size,
+      // then skip it
+      if ((regionsOfInterest[i].width < config->minPlateSizeWidthPx) ||
+          (regionsOfInterest[i].height < config->minPlateSizeHeightPx))
+        continue;
+
+      Mat cropped = frame_gray(regionsOfInterest[i]);
+      vector<PlateRegion> subRegions = doCascade(cropped, regionsOfInterest[i].x, regionsOfInterest[i].y);
+
+      for (int j = 0; j < subRegions.size(); j++)
+        detectedRegions.push_back(subRegions[j]);
+    }
+    return detectedRegions;
+  }
+
+  vector<PlateRegion> DetectorOCL::doCascade(Mat orig_frame, int offset_x, int offset_y)
+  {
+
+    int w = orig_frame.size().width;
+    int h = orig_frame.size().height;
+
+    float scale_factor = computeScaleFactor(w, h);
+
+    UMat openclFrame;
+    orig_frame.copyTo(openclFrame);
+
+    vector<Rect> plates;
+
+    equalizeHist( openclFrame, openclFrame );
+
+    if (scale_factor != 1.0)
+      resize(openclFrame, openclFrame, Size(w * scale_factor, h * scale_factor));
+
+    //-- Detect plates
+    timespec startTime;
+    getTimeMonotonic(&startTime);
+
+    float maxWidth = ((float) w) * (config->maxPlateWidthPercent / 100.0f) * scale_factor;
+    float maxHeight = ((float) h) * (config->maxPlateHeightPercent / 100.0f) * scale_factor;
+    Size minSize(config->minPlateSizeWidthPx * scale_factor, config->minPlateSizeHeightPx * scale_factor);
+    Size maxSize(maxWidth, maxHeight);
+
+    plate_cascade.detectMultiScale( openclFrame, plates, config->detection_iteration_increase, config->detectionStrictness,
+                                    0,
+        //0|CV_HAAR_SCALE_IMAGE,
+                                    minSize, maxSize );
+
+
+    if (config->debugTiming)
+    {
+      timespec endTime;
+      getTimeMonotonic(&endTime);
+      cout << "LBP Time: " << diffclock(startTime, endTime) << "ms." << endl;
+    }
+
+    for( unsigned int i = 0; i < plates.size(); i++ )
+    {
+      plates[i].x = (plates[i].x / scale_factor);
+      plates[i].y = (plates[i].y / scale_factor);
+      plates[i].width = plates[i].width / scale_factor;
+      plates[i].height = plates[i].height / scale_factor;
+
+      // Ensure that the rectangle isn't < 0 or > maxWidth/Height
+      plates[i] = expandRect(plates[i], 0, 0, w, h);
+
+      plates[i].x = plates[i].x + offset_x;
+      plates[i].y = plates[i].y + offset_y;
+    }
+
+    vector<PlateRegion> orderedRegions = aggregateRegions(plates);
+
+    return orderedRegions;
+
+  }
+
+}
+
+#endif

src/openalpr/detection/detectorocl.h

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2015 OpenALPR Technology, Inc.
+ * Open source 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_DETECTOROPENCL_H
+#define	OPENALPR_DETECTOROPENCL_H
+
+#include <stdio.h>
+#include <iostream>
+#include <vector>
+
+#if OPENCV_MAJOR_VERSION == 3
+
+#include "opencv2/objdetect/objdetect.hpp"
+#include "opencv2/imgproc/imgproc.hpp"
+#include "opencv2/core/core.hpp"
+#include "opencv2/ml/ml.hpp"
+#include "opencv2/core/ocl.hpp"
+
+#include "detector.h"
+
+namespace alpr
+{
+
+  class DetectorOCL : public Detector {
+  public:
+    DetectorOCL(Config* config);
+    virtual ~DetectorOCL();
+
+    std::vector<PlateRegion> detect(cv::Mat frame, std::vector<cv::Rect> regionsOfInterest);
+
+  private:
+
+    cv::CascadeClassifier plate_cascade;
+
+    std::vector<PlateRegion> doCascade(cv::Mat frame, int offset_x, int offset_y);
+  };
+
+}
+
+#endif
+
+#endif	/* OPENALPR_DETECTOROPENCL_H */
+