refactor integral channels

modules/objdetect/include/opencv2/objdetect/objdetect.hpp

@@ -511,6 +511,29 @@ public:
         int kind;
     };
 
+    // Create channel integrals for Soft Cascade detector.
+    class CV_EXPORTS Channels
+    {
+    public:
+        // constrictor form resizing factor.
+        // Param shr is a resizing factor. Resize is applied before the computing integral sum
+        Channels(const int shrinkage);
+
+        // Appends specified number of HOG first-order features integrals into given vector.
+        // Param gray is an input 1-channel gray image.
+        // Param integrals is a vector of integrals. Hog-channels will be appended to it.
+        // Param bins is a number of hog-bins
+        void appendHogBins(const cv::Mat gray, std::vector<cv::Mat>& integrals, int bins) const;
+
+        // Converts 3-channel BGR input frame in  Luv and appends each channel to the integrals.
+        // Param frame is an input 3-channel BGR colored image.
+        // Param integrals is a vector of integrals. Computed from the frame luv-channels will be appended to it.
+        void appendLuvBins(const cv::Mat frame, std::vector<cv::Mat>& integrals) const;
+
+    private:
+        int shrinkage;
+    };
+
     // An empty cascade will be created.
     // Param minScale is a minimum scale relative to the original size of the image on which cascade will be applyed.
     // Param minScale is a maximum scale relative to the original size of the image on which cascade will be applyed.
@@ -547,32 +570,6 @@ private:
 
 CV_EXPORTS bool initModule_objdetect(void);
 
-/**
- * \class IntegralChannels
- * \brief Create channel integrals for Soft Cascade detector.
- */
-class CV_EXPORTS IntegralChannels
-{
-public:
-    //! constrictor form resizing factor.
-    //! Param shr is a resizing factor. Resize is applied before integral sum computing
-    IntegralChannels(const int shr) : shrinkage(shr) {}
-
-    //! Appends specified number of hog first order feature integrals into given vector.
-    //! Param gray is an input 1-chennel gray image.
-    //! Param integrals is a vector of integrals. Computed from frame frame hog-channels will be appended to it.
-    //! Param bins is a number of hog-bins
-    void createHogBins(const cv::Mat gray, std::vector<cv::Mat>& integrals, int bins) const;
-
-    //! Converts 3-chennel BGR input frame to Luv and append each channel to the integrals.
-    //! Param frame is an input 3-chennel BGR colored image.
-    //! Param integrals is a vector of integrals. Computed from frame frame luv-channels will be appended to it.
-    void createLuvBins(const cv::Mat frame, std::vector<cv::Mat>& integrals) const;
-
-private:
-    int shrinkage;
-};
-
 //////////////// HOG (Histogram-of-Oriented-Gradients) Descriptor and Object Detector //////////////
 
 // struct for detection region of interest (ROI)

modules/objdetect/src/icf.cpp

@@ -44,7 +44,9 @@
 #include <opencv2/objdetect/objdetect.hpp>
 #include <opencv2/core/core.hpp>
 
-void cv::IntegralChannels::createHogBins(const cv::Mat gray, std::vector<cv::Mat>& integrals, int bins) const
+cv::SCascade::Channels::Channels(int shr) : shrinkage(shr) {}
+
+void cv::SCascade::Channels::appendHogBins(const cv::Mat gray, std::vector<cv::Mat>& integrals, int bins) const
 {
     CV_Assert(gray.type() == CV_8UC1);
     int h = gray.rows;
@@ -52,11 +54,11 @@ void cv::IntegralChannels::createHogBins(const cv::Mat gray, std::vector<cv::Mat
     CV_Assert(!(w % shrinkage) && !(h % shrinkage));
 
     cv::Mat df_dx, df_dy, mag, angle;
-    cv::Sobel(gray, df_dx, CV_32F, 1, 0, 3, 0.125);
-    cv::Sobel(gray, df_dy, CV_32F, 0, 1, 3, 0.125);
+    cv::Sobel(gray, df_dx, CV_32F, 1, 0);
+    cv::Sobel(gray, df_dy, CV_32F, 0, 1);
 
     cv::cartToPolar(df_dx, df_dy, mag, angle, true);
-    mag *= (1.f / sqrt(2));
+    mag *= (1.f / (8 * sqrt(2)));
 
     cv::Mat nmag;
     mag.convertTo(nmag, CV_8UC1);
@@ -92,22 +94,22 @@ void cv::IntegralChannels::createHogBins(const cv::Mat gray, std::vector<cv::Mat
     integrals.push_back(mag);
 }
 
-void cv::IntegralChannels::createLuvBins(const cv::Mat frame, std::vector<cv::Mat>& integrals) const
+void cv::SCascade::Channels::appendLuvBins(const cv::Mat frame, std::vector<cv::Mat>& integrals) const
 {
     CV_Assert(frame.type() == CV_8UC3);
     CV_Assert(!(frame.cols % shrinkage) && !(frame.rows % shrinkage));
 
-    cv::Mat luv;
+    cv::Mat luv, shrunk;
     cv::cvtColor(frame, luv, CV_BGR2Luv);
+    cv::resize(luv, shrunk, cv::Size(), 1.0 / shrinkage, 1.0 / shrinkage, CV_INTER_AREA);
 
     std::vector<cv::Mat> splited;
-    split(luv, splited);
+    split(shrunk, splited);
 
     for (size_t i = 0; i < splited.size(); ++i)
     {
-        cv::Mat shrunk, sum;
-        cv::resize(splited[i], shrunk, cv::Size(), 1.0 / shrinkage, 1.0 / shrinkage, CV_INTER_AREA);
-        cv::integral(shrunk, sum, cv::noArray(), CV_32S);
+        cv::Mat sum;
+        cv::integral(splited[i], sum, cv::noArray(), CV_32S);
         integrals.push_back(sum);
     }
 }

modules/objdetect/src/softcascade.cpp

@@ -223,14 +223,15 @@ struct ChannelStorage
     ChannelStorage(const cv::Mat& colored, int shr) : shrinkage(shr)
     {
         hog.clear();
-        cv::IntegralChannels ints(shr);
+        hog.reserve(10);
+        cv::SCascade::Channels ints(shr);
 
         // convert to grey
         cv::Mat grey;
         cv::cvtColor(colored, grey, CV_BGR2GRAY);
 
-        ints.createHogBins(grey, hog, 6);
-        ints.createLuvBins(colored, hog);
+        ints.appendHogBins(grey, hog, 6);
+        ints.appendLuvBins(colored, hog);
 
         step = hog[0].cols;
     }