[+] Added Brox optical flow (implementation courtesy of Michael Smirnov)

modules/gpu/src/nvidia/NCVBroxOpticalFlow.hpp

+/*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) 2009-2010, NVIDIA Corporation, 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*/
+
+////////////////////////////////////////////////////////////////////////////////
+//
+// NVIDIA CUDA implementation of Brox et al Optical Flow algorithm
+//
+// Algorithm is explained in the original paper:
+//      T. Brox, A. Bruhn, N. Papenberg, J. Weickert:
+//      High accuracy optical flow estimation based on a theory for warping.
+//      ECCV 2004.
+//
+// Implementation by Mikhail Smirnov
+// email: msmirnov@nvidia.com, devsupport@nvidia.com
+//
+// Credits for help with the code to:
+// Alexey Mendelenko, Anton Obukhov, and Alexander Kharlamov.
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef _ncv_optical_flow_h_
+#define _ncv_optical_flow_h_
+
+#include "NCV.hpp"
+
+/// \brief Model and solver parameters
+struct NCVBroxOpticalFlowDescriptor
+{
+	/// flow smoothness
+	Ncv32f alpha;
+	/// gradient constancy importance
+	Ncv32f gamma;
+	/// pyramid scale factor
+	Ncv32f scale_factor;
+	/// number of lagged non-linearity iterations (inner loop)
+	Ncv32u number_of_inner_iterations;
+	/// number of warping iterations (number of pyramid levels)
+	Ncv32u number_of_outer_iterations;
+	/// number of linear system solver iterations
+	Ncv32u number_of_solver_iterations;
+};
+
+/////////////////////////////////////////////////////////////////////////////////////////
+/// \brief Compute optical flow
+///
+/// Based on method by Brox et al [2004]
+/// \param [in]  desc              model and solver parameters
+/// \param [in]  gpu_mem_allocator GPU memory allocator
+/// \param [in]  frame0            source frame
+/// \param [in]  frame1            frame to track
+/// \param [out] u                 flow horizontal component (along \b x axis)
+/// \param [out] v                 flow vertical component (along \b y axis)
+/// \return                        computation status
+/////////////////////////////////////////////////////////////////////////////////////////
+
+NCV_EXPORTS
+NCVStatus NCVBroxOpticalFlow(const NCVBroxOpticalFlowDescriptor desc,
+							 INCVMemAllocator &gpu_mem_allocator,
+							 const NCVMatrix<Ncv32f> &frame0,
+							 const NCVMatrix<Ncv32f> &frame1,
+							 NCVMatrix<Ncv32f> &u,
+							 NCVMatrix<Ncv32f> &v,
+							 cudaStream_t stream);
+
+#endif