move frame processing into separate class

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

@@ -543,6 +543,28 @@ private:
     Filds* filds;
 };
 
+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/isf.cpp

+/*M///////////////////////////////////////////////////////////////////////////////////////
+//
+//  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
+//
+//  By downloading, copying, installing or using the software you agree to this license.
+//  If you do not agree to this license, do not download, install,
+//  copy or use the software.
+//
+//
+//                           License Agreement
+//                For Open Source Computer Vision Library
+//
+// Copyright (C) 2000-2008, Intel Corporation, all rights reserved.
+// Copyright (C) 2008-2012, Willow Garage Inc., all rights reserved.
+// Third party copyrights are property of their respective owners.
+//
+// Redistribution and use in source and binary forms, with or without modification,
+// are permitted provided that the following conditions are met:
+//
+//   * Redistribution's of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//
+//   * Redistribution's in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//
+//   * The name of the copyright holders may not be used to endorse or promote products
+//     derived from this software without specific prior written permission.
+//
+// This software is provided by the copyright holders and contributors "as is" and
+// any express or implied warranties, including, but not limited to, the implied
+// warranties of merchantability and fitness for a particular purpose are disclaimed.
+// In no event shall the Intel Corporation or contributors be liable for any direct,
+// indirect, incidental, special, exemplary, or consequential damages
+// (including, but not limited to, procurement of substitute goods or services;
+// loss of use, data, or profits; or business interruption) however caused
+// and on any theory of liability, whether in contract, strict liability,
+// or tort (including negligence or otherwise) arising in any way out of
+// the use of this software, even if advised of the possibility of such damage.
+//
+//M*/
+
+#include <precomp.hpp>
+#include <opencv2/objdetect/objdetect.hpp>
+#include <opencv2/core/core.hpp>
+
+
+template<typename T>
+struct Decimate {
+    int shrinkage;
+
+    Decimate(const int sr) : shrinkage(sr) {}
+
+    void operator()(const cv::Mat& in, cv::Mat& out) const
+    {
+        int cols = in.cols / shrinkage;
+        int rows = in.rows / shrinkage;
+        out.create(rows, cols, in.type());
+
+        CV_Assert(cols * shrinkage == in.cols);
+        CV_Assert(rows * shrinkage == in.rows);
+
+        for (int outIdx_y = 0; outIdx_y < rows; ++outIdx_y)
+        {
+            T* outPtr = out.ptr<T>(outIdx_y);
+            for (int outIdx_x = 0; outIdx_x < cols; ++outIdx_x)
+            {
+                // do desimate
+                int inIdx_y = outIdx_y * shrinkage;
+                int inIdx_x = outIdx_x * shrinkage;
+                int sum = 0;
+
+                for (int y = inIdx_y; y < inIdx_y + shrinkage; ++y)
+                    for (int x = inIdx_x; x < inIdx_x + shrinkage; ++x)
+                        sum += in.at<T>(y, x);
+
+                sum /= shrinkage * shrinkage;
+                outPtr[outIdx_x] = cv::saturate_cast<T>(sum);
+            }
+        }
+    }
+
+};
+
+void cv::IntegralChannels::createHogBins(const cv::Mat gray, std::vector<cv::Mat>& integrals, int bins) const
+{
+    CV_Assert(gray.type() == CV_8UC1);
+    int h = gray.rows;
+    int w = gray.cols;
+    CV_Assert(!(w % shrinkage) && !(h % shrinkage));
+
+    Decimate<uchar> decimate(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::cartToPolar(df_dx, df_dy, mag, angle, true);
+    mag *= (1.f / sqrt(2));
+
+    cv::Mat nmag;
+    mag.convertTo(nmag, CV_8UC1);
+
+    angle /= 60.f;
+
+    std::vector<cv::Mat> hist;
+    for (int bin = 0; bin < bins; ++bin)
+        hist.push_back(cv::Mat::zeros(h, w, CV_8UC1));
+
+    for (int y = 0; y < h; ++y)
+    {
+        uchar* magnitude = nmag.ptr<uchar>(y);
+        float* ang = angle.ptr<float>(y);
+
+        for (int x = 0; x < w; ++x)
+        {
+            hist[ (int)ang[x] ].ptr<uchar>(y)[x] = magnitude[x];
+        }
+    }
+
+    for(int i = 0; i < bins; ++i)
+    {
+        cv::Mat shrunk, sum;
+        decimate(hist[i], shrunk);
+        cv::integral(shrunk, sum, cv::noArray(), CV_32S);
+        integrals.push_back(sum);
+    }
+
+    cv::Mat shrMag;
+    decimate(nmag, shrMag);
+    cv::integral(shrMag, mag, cv::noArray(), CV_32S);
+    integrals.push_back(mag);
+}
+
+void cv::IntegralChannels::createLuvBins(const cv::Mat frame, std::vector<cv::Mat>& integrals) const
+{
+    CV_Assert(frame.type() == CV_8UC3);
+    CV_Assert(!(frame.cols % shrinkage) && !(frame.rows % shrinkage));
+
+    Decimate<uchar> decimate(shrinkage);
+
+    cv::Mat luv;
+    cv::cvtColor(frame, luv, CV_BGR2Luv);
+
+    std::vector<cv::Mat> splited;
+    split(luv, splited);
+
+    for (size_t i = 0; i < splited.size(); ++i)
+    {
+        cv::Mat shrunk, sum;
+        decimate(splited[i], shrunk);
+        cv::integral(shrunk, sum, cv::noArray(), CV_32S);
+        integrals.push_back(sum);
+    }
+}
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