Moved optflow interfaces and testing app.

Algorithm::info()-related code disabled-after moving to opencv_contrib caused compilation errors

Added usage examples

Added documentation for optflow_io

+bugfix: handling invalid algorithm choice

+ solving MSVC compilation errors; assuming that int and float are 4-bytes long - possibly needs fixing

modules/optflow/doc/optflow.rst

@@ -11,3 +11,4 @@ The opencv_optflow module includes different algorithms for tracking points
 
     dense_optflow
     motion_templates
+    optflow_io

modules/optflow/doc/optflow_io.rst

+Optical flow input / output
+============================
+
+Functions reading and writing .flo files in "Middlebury" format, see: [MiddleburyFlo]_ 
+
+readOpticalFlow
+-----------------
+Read a .flo file
+
+.. ocv:function:: Mat readOpticalFlow( const String& path )
+    
+    :param path: Path to the file to be loaded
+    
+The function readOpticalFlow loads a flow field from a file and returns it as a single matrix.
+Resulting ``Mat`` has a type ``CV_32FC2`` - floating-point, 2-channel. 
+First channel corresponds to the flow in the horizontal direction (u), second - vertical (v).
+
+writeOpticalFlow
+-----------------
+Write a .flo to disk
+
+.. ocv:function:: bool writeOpticalFlow( const String& path, InputArray flow )
+
+    :param path: Path to the file to be written
+    
+    :param flow: Flow field to be stored
+    
+ The function stores a flow field in a file, returns ``true`` on success, ``false`` otherwise.
+
+ The flow field must be a 2-channel, floating-point matrix (``CV_32FC2``). 
+ First channel corresponds to the flow in the horizontal direction (u), second - vertical (v).
+ 
+ 
+.. [MiddleburyFlo] http://vision.middlebury.edu/flow/code/flow-code/README.txt
+ 
+ 
\ No newline at end of file

modules/optflow/include/opencv2/optflow.hpp

@@ -41,6 +41,7 @@ the use of this software, even if advised of the possibility of such damage.
 #define __OPENCV_OPTFLOW_HPP__
 
 #include "opencv2/core.hpp"
+#include "opencv2/video.hpp"
 
 namespace cv
 {
@@ -57,8 +58,26 @@ CV_EXPORTS_W void calcOpticalFlowSF( InputArray from, InputArray to, OutputArray
                                      double sigma_dist_fix, double sigma_color_fix, double occ_thr,
                                      int upscale_averaging_radius, double upscale_sigma_dist,
                                      double upscale_sigma_color, double speed_up_thr );    
-    
-}
+
+//! reads optical flow from a file, Middlebury format:
+// http://vision.middlebury.edu/flow/code/flow-code/README.txt
+CV_EXPORTS_W Mat readOpticalFlow( const String& path );
+//! writes optical flow to a file, Middlebury format
+CV_EXPORTS_W bool writeOpticalFlow( const String& path, InputArray flow );
+
+
+
+
+// DeepFlow implementation, based on:
+//   P. Weinzaepfel, J. Revaud, Z. Harchaoui, and C. Schmid, “DeepFlow: Large Displacement Optical Flow with Deep Matching,”
+//CV_EXPORTS_W Ptr<DenseOpticalFlow> createOptFlow_DeepFlow();
+
+// Additional interface to the SimpleFlow algorithm - calcOpticalFlowSF()
+CV_EXPORTS_W Ptr<DenseOpticalFlow> createOptFlow_SimpleFlow();
+
+// Additional interface to the Farneback's algorithm - calcOpticalFlowFarneback()
+CV_EXPORTS_W Ptr<DenseOpticalFlow> createOptFlow_Farneback();
+} //optflow
 }
 
 #include "opencv2/optflow/motempl.hpp"

modules/optflow/src/interfaces.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) 2009, 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/core.hpp"
+#include "opencv2/highgui.hpp"
+#include "opencv2/video.hpp"
+#include "opencv2/optflow.hpp"
+
+namespace cv
+{
+namespace optflow
+{
+class OpticalFlowSimpleFlow : public DenseOpticalFlow
+{
+public:
+    OpticalFlowSimpleFlow();
+    void calc(InputArray I0, InputArray I1, InputOutputArray flow);
+    void collectGarbage();
+//    AlgorithmInfo* info() const;
+
+protected:
+    int layers;
+    int averaging_radius;
+    int max_flow;
+    double sigma_dist;
+    double sigma_color;
+    int postprocess_window;
+    double sigma_dist_fix;
+    double sigma_color_fix;
+    double occ_thr;
+    int upscale_averaging_radius;
+    double upscale_sigma_dist;
+    double upscale_sigma_color;
+    double speed_up_thr;
+};
+
+OpticalFlowSimpleFlow::OpticalFlowSimpleFlow()
+{
+    // values from the example app
+    layers = 3;
+    averaging_radius = 2;
+    max_flow = 4;
+    // values from the default function parameters
+    sigma_dist = 4.1;
+    sigma_color = 25.5;
+    postprocess_window = 18;
+    sigma_dist_fix = 55.0;
+    sigma_color_fix = 25.5;
+    occ_thr = 0.35;
+    upscale_averaging_radius = 18;
+    upscale_sigma_dist = 55.0;
+    upscale_sigma_color = 25.5;
+    speed_up_thr = 10;
+}
+
+void OpticalFlowSimpleFlow::calc(InputArray I0, InputArray I1, InputOutputArray flow)
+{
+    optflow::calcOpticalFlowSF(I0, I1, flow, layers, averaging_radius, max_flow, sigma_dist, sigma_color,
+                      postprocess_window, sigma_dist_fix, sigma_color_fix, occ_thr,
+                      upscale_averaging_radius, upscale_sigma_dist, upscale_sigma_color, speed_up_thr);
+}
+void OpticalFlowSimpleFlow::collectGarbage()
+{
+
+}
+//CV_INIT_ALGORITHM(OpticalFlowSimpleFlow, "DenseOpticalFlow.SimpleFlow"),
+//        obj.info()->addParam(obj, "layers", obj.layers);
+//        obj.info()->addParam(obj, "averaging_radius", obj.averaging_radius);
+//        obj.info()->addParam(obj, "max_flow", obj.max_flow);
+//        obj.info()->addParam(obj, "sigma_dist", obj.sigma_dist);
+//        obj.info()->addParam(obj, "sigma_color", obj.sigma_color);
+//        obj.info()->addParam(obj, "postprocess_window", obj.postprocess_window);
+//        obj.info()->addParam(obj, "sigma_dist_fix", obj.sigma_dist_fix);
+//        obj.info()->addParam(obj, "sigma_color_fix", obj.sigma_color_fix);
+//        obj.info()->addParam(obj, "occ_thr", obj.occ_thr);
+//        obj.info()->addParam(obj, "upscale_averaging_radius", obj.upscale_averaging_radius);
+//        obj.info()->addParam(obj, "upscale_sigma_dist", obj.upscale_sigma_dist);
+//        obj.info()->addParam(obj, "upscale_sigma_color", obj.upscale_sigma_color);
+//        obj.info()->addParam(obj, "speed_up_thr", obj.speed_up_thr))
+
+Ptr<DenseOpticalFlow> createOptFlow_SimpleFlow()
+{
+    return makePtr<OpticalFlowSimpleFlow>();
+}
+
+class OpticalFlowFarneback : public DenseOpticalFlow
+{
+public:
+    OpticalFlowFarneback();
+    void calc(InputArray I0, InputArray I1, InputOutputArray flow);
+    void collectGarbage();
+//    AlgorithmInfo* info() const;
+protected:
+    int numLevels;
+    double pyrScale;
+    bool fastPyramids;
+    int winSize;
+    int numIters;
+    int polyN;
+    double polySigma;
+    int flags;
+};
+
+OpticalFlowFarneback::OpticalFlowFarneback()
+{
+    // values copied from the FarnebackOpticalFlow class
+    numLevels = 5;
+    pyrScale = 0.5;
+    fastPyramids = false;
+    winSize = 13;
+    numIters = 10;
+    polyN = 5;
+    polySigma = 1.1;
+    flags = 0;
+}
+
+void OpticalFlowFarneback::calc(InputArray I0, InputArray I1, InputOutputArray flow)
+{
+    calcOpticalFlowFarneback(I0, I1, flow, pyrScale, numLevels, winSize, numIters, polyN, polySigma, flags);
+}
+void OpticalFlowFarneback::collectGarbage()
+{
+}
+
+//CV_INIT_ALGORITHM(OpticalFlowFarneback, "DenseOpticalFlow.Farneback",
+//        obj.info()->addParam(obj, "numLevels", obj.numLevels);
+//        obj.info()->addParam(obj, "pyrScale", obj.pyrScale);
+//        obj.info()->addParam(obj, "fastPyramids", obj.fastPyramids);
+//        obj.info()->addParam(obj, "winSize", obj.winSize);
+//        obj.info()->addParam(obj, "numIters", obj.numIters);
+//        obj.info()->addParam(obj, "polyN", obj.polyN);
+//        obj.info()->addParam(obj, "polySigma", obj.polySigma);
+//        obj.info()->addParam(obj, "flags", obj.flags))
+
+
+
+
+Ptr<DenseOpticalFlow> createOptFlow_Farneback()
+{
+    return makePtr<OpticalFlowFarneback>();
+}
+}
+}

modules/optflow/src/optical_flow_io.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) 2009, 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<iostream>
+#include<fstream>
+
+namespace cv {
+namespace optflow {
+const float FLOW_TAG_FLOAT = 202021.25f;
+const char *FLOW_TAG_STRING = "PIEH";
+CV_EXPORTS_W Mat readOpticalFlow( const String& path )
+{
+//    CV_Assert(sizeof(float) == 4);
+    //FIXME: ensure right sizes of int and float - here and in writeOpticalFlow()
+
+    Mat_<Point2f> flow;
+    std::ifstream file(path.c_str(), std::ios_base::binary);
+    if ( !file.good() )
+        return flow; // no file - return empty matrix
+
+    float tag;
+    file.read((char*) &tag, sizeof(float));
+    if ( tag != FLOW_TAG_FLOAT )
+        return flow;
+
+    int width, height;
+
+    file.read((char*) &width, 4);
+    file.read((char*) &height, 4);
+
+    flow.create(height, width);
+
+    for ( int i = 0; i < flow.rows; ++i )
+    {
+        for ( int j = 0; j < flow.cols; ++j )
+        {
+            Point2f u;
+            file.read((char*) &u.x, sizeof(float));
+            file.read((char*) &u.y, sizeof(float));
+            if ( !file.good() )
+            {
+                flow.release();
+                return flow;
+            }
+
+            flow(i, j) = u;
+        }
+    }
+    file.close();
+    return flow;
+}
+CV_EXPORTS_W bool writeOpticalFlow( const String& path, InputArray flow )
+{
+//    CV_Assert(sizeof(float) == 4);
+
+    const int nChannels = 2;
+
+    Mat input = flow.getMat();
+    if ( input.channels() != nChannels || input.depth() != CV_32F || path.length() == 0 )
+        return false;
+
+    std::ofstream file(path.c_str(), std::ofstream::binary);
+    if ( !file.good() )
+        return false;
+
+    int nRows, nCols;
+
+    nRows = (int) input.size().height;
+    nCols = (int) input.size().width;
+
+    const int headerSize = 12;
+    char header[headerSize];
+    memcpy(header, FLOW_TAG_STRING, 4);
+    // size of ints is known - has been asserted in the current function
+    memcpy(header + 4, reinterpret_cast<const char*>(&nCols), sizeof(nCols));
+    memcpy(header + 8, reinterpret_cast<const char*>(&nRows), sizeof(nRows));
+    file.write(header, headerSize);
+    if ( !file.good() )
+        return false;
+
+//    if ( input.isContinuous() ) //matrix is continous - treat it as a single row
+//    {
+//        nCols *= nRows;
+//        nRows = 1;
+//    }
+
+    int row;
+    char* p;
+    for ( row = 0; row < nRows; row++ )
+    {
+        p = input.ptr<char>(row);
+        file.write(p, nCols * nChannels * sizeof(float));
+        if ( !file.good() )
+            return false;
+    }
+    file.close();
+    return true;
+}
+}
+}