Commit 1c6b74d7 authored by Namgoo Lee's avatar Namgoo Lee
Browse files

[moved from opencv] Fix Farneback Optical Flow Algorithm 

- Before this PR, following tests failed on some platform.
  CUDA_OptFlow/FarnebackOpticalFlow.Accuracy/19
  CUDA_OptFlow/FarnebackOpticalFlow.Accuracy/23

- The algorithm now recognizes the OPTFLOW_USE_INITIAL_FLOW flag.
  Previously, when the flag was set, it did not use the flow data
  passed as input, instead used some garbage data in memory.

- More strict test limit.

original commit: https://github.com/opencv/opencv/commit/4366c8734fa7cf69c4a9bdcea91f41d1af345e9c
parent ab2e8324

modules/cudaoptflow/src/farneback.cpp

+22 −7
Original line number Diff line number Diff line
@@ -165,10 +165,29 @@ namespace 
    {

        const GpuMat frame0 = _frame0.getGpuMat();

        const GpuMat frame1 = _frame1.getGpuMat();

        GpuMat flow = _flow.getGpuMat();



        BufferPool pool(stream);

        GpuMat flowx = pool.getBuffer(frame0.size(), CV_32FC1);

        GpuMat flowy = pool.getBuffer(frame0.size(), CV_32FC1);

        CV_Assert(frame0.channels() == 1 && frame1.channels() == 1);

        CV_Assert(frame0.size() == frame1.size());



        GpuMat flowx, flowy;



        // If flag is set, check for integrity; if not set, allocate memory space

        if (flags_ & OPTFLOW_USE_INITIAL_FLOW)

        {

            CV_Assert(flow.size() == frame0.size() && flow.channels() == 2 &&

                      flow.depth() == CV_32F);



            std::vector<cuda::GpuMat> _flows(2);

            cuda::split(flow, _flows, stream);

            flowx = _flows[0];

            flowy = _flows[1];

        }

        else

        {

            flowx.create(frame0.size(), CV_32FC1);

            flowy.create(frame0.size(), CV_32FC1);

        }



        calcImpl(frame0, frame1, flowx, flowy, stream);
@@ -291,8 +310,6 @@ namespace 


    void FarnebackOpticalFlowImpl::calcImpl(const GpuMat &frame0, const GpuMat &frame1, GpuMat &flowx, GpuMat &flowy, Stream &stream)

    {

        CV_Assert(frame0.channels() == 1 && frame1.channels() == 1);

        CV_Assert(frame0.size() == frame1.size());

        CV_Assert(polyN_ == 5 || polyN_ == 7);

        CV_Assert(!fastPyramids_ || std::abs(pyrScale_ - 0.5) < 1e-6);
@@ -303,8 +320,6 @@ namespace 
        Size size = frame0.size();

        GpuMat prevFlowX, prevFlowY, curFlowX, curFlowY;



        flowx.create(size, CV_32F);

        flowy.create(size, CV_32F);

        GpuMat flowx0 = flowx;

        GpuMat flowy0 = flowy;

modules/cudaoptflow/test/test_optflow.cpp

+9 −1
Original line number Diff line number Diff line
@@ -337,7 +337,15 @@ CUDA_TEST_P(FarnebackOpticalFlow, Accuracy) 
        frame0, frame1, flow, farn->getPyrScale(), farn->getNumLevels(), farn->getWinSize(),

        farn->getNumIters(), farn->getPolyN(), farn->getPolySigma(), farn->getFlags());



    EXPECT_MAT_SIMILAR(flow, d_flow, 0.1);

    // Relax test limit when the flag is set

    if (farn->getFlags() & cv::OPTFLOW_FARNEBACK_GAUSSIAN)

    {

        EXPECT_MAT_SIMILAR(flow, d_flow, 2e-2);

    }

    else

    {

        EXPECT_MAT_SIMILAR(flow, d_flow, 1e-4);

    }

}



INSTANTIATE_TEST_CASE_P(CUDA_OptFlow, FarnebackOpticalFlow, testing::Combine(