Commit 18dbed0e authored by atinfinity's avatar atinfinity

added dense flow sample

parent a2fed4c7
......@@ -2,12 +2,13 @@
#include <vector>
#include "opencv2/core.hpp"
#include <opencv2/core/utility.hpp>
#include "opencv2/core/utility.hpp"
#include "opencv2/imgproc.hpp"
#include "opencv2/highgui.hpp"
#include "opencv2/video.hpp"
#include "opencv2/cudaoptflow.hpp"
#include "opencv2/cudaimgproc.hpp"
#include "opencv2/cudaarithm.hpp"
using namespace std;
using namespace cv;
......@@ -66,6 +67,132 @@ static void drawArrows(Mat& frame, const vector<Point2f>& prevPts, const vector<
}
}
inline bool isFlowCorrect(Point2f u)
{
return !cvIsNaN(u.x) && !cvIsNaN(u.y) && fabs(u.x) < 1e9 && fabs(u.y) < 1e9;
}
static Vec3b computeColor(float fx, float fy)
{
static bool first = true;
// relative lengths of color transitions:
// these are chosen based on perceptual similarity
// (e.g. one can distinguish more shades between red and yellow
// than between yellow and green)
const int RY = 15;
const int YG = 6;
const int GC = 4;
const int CB = 11;
const int BM = 13;
const int MR = 6;
const int NCOLS = RY + YG + GC + CB + BM + MR;
static Vec3i colorWheel[NCOLS];
if (first)
{
int k = 0;
for (int i = 0; i < RY; ++i, ++k)
colorWheel[k] = Vec3i(255, 255 * i / RY, 0);
for (int i = 0; i < YG; ++i, ++k)
colorWheel[k] = Vec3i(255 - 255 * i / YG, 255, 0);
for (int i = 0; i < GC; ++i, ++k)
colorWheel[k] = Vec3i(0, 255, 255 * i / GC);
for (int i = 0; i < CB; ++i, ++k)
colorWheel[k] = Vec3i(0, 255 - 255 * i / CB, 255);
for (int i = 0; i < BM; ++i, ++k)
colorWheel[k] = Vec3i(255 * i / BM, 0, 255);
for (int i = 0; i < MR; ++i, ++k)
colorWheel[k] = Vec3i(255, 0, 255 - 255 * i / MR);
first = false;
}
const float rad = sqrt(fx * fx + fy * fy);
const float a = atan2(-fy, -fx) / (float)CV_PI;
const float fk = (a + 1.0f) / 2.0f * (NCOLS - 1);
const int k0 = static_cast<int>(fk);
const int k1 = (k0 + 1) % NCOLS;
const float f = fk - k0;
Vec3b pix;
for (int b = 0; b < 3; b++)
{
const float col0 = colorWheel[k0][b] / 255.0f;
const float col1 = colorWheel[k1][b] / 255.0f;
float col = (1 - f) * col0 + f * col1;
if (rad <= 1)
col = 1 - rad * (1 - col); // increase saturation with radius
else
col *= .75; // out of range
pix[2 - b] = static_cast<uchar>(255.0 * col);
}
return pix;
}
static void drawOpticalFlow(const Mat_<float>& flowx, const Mat_<float>& flowy, Mat& dst, float maxmotion = -1)
{
dst.create(flowx.size(), CV_8UC3);
dst.setTo(Scalar::all(0));
// determine motion range:
float maxrad = maxmotion;
if (maxmotion <= 0)
{
maxrad = 1;
for (int y = 0; y < flowx.rows; ++y)
{
for (int x = 0; x < flowx.cols; ++x)
{
Point2f u(flowx(y, x), flowy(y, x));
if (!isFlowCorrect(u))
continue;
maxrad = max(maxrad, sqrt(u.x * u.x + u.y * u.y));
}
}
}
for (int y = 0; y < flowx.rows; ++y)
{
for (int x = 0; x < flowx.cols; ++x)
{
Point2f u(flowx(y, x), flowy(y, x));
if (isFlowCorrect(u))
dst.at<Vec3b>(y, x) = computeColor(u.x / maxrad, u.y / maxrad);
}
}
}
static void showFlow(const char* name, const GpuMat& d_flow)
{
GpuMat planes[2];
cuda::split(d_flow, planes);
Mat flowx(planes[0]);
Mat flowy(planes[1]);
Mat out;
drawOpticalFlow(flowx, flowy, out, 10);
imshow(name, out);
}
template <typename T> inline T clamp (T x, T a, T b)
{
return ((x) > (a) ? ((x) < (b) ? (x) : (b)) : (a));
......@@ -148,7 +275,7 @@ int main(int argc, const char* argv[])
// Sparse
Ptr<cuda::SparsePyrLKOpticalFlow> d_pyrLK = cuda::SparsePyrLKOpticalFlow::create(
Ptr<cuda::SparsePyrLKOpticalFlow> d_pyrLK_sparse = cuda::SparsePyrLKOpticalFlow::create(
Size(winSize, winSize), maxLevel, iters);
GpuMat d_frame0(frame0);
......@@ -157,7 +284,16 @@ int main(int argc, const char* argv[])
GpuMat d_nextPts;
GpuMat d_status;
d_pyrLK->calc(useGray ? d_frame0Gray : d_frame0, useGray ? d_frame1Gray : d_frame1, d_prevPts, d_nextPts, d_status);
d_pyrLK_sparse->calc(useGray ? d_frame0Gray : d_frame0, useGray ? d_frame1Gray : d_frame1, d_prevPts, d_nextPts, d_status);
// Dense
Ptr<cuda::DensePyrLKOpticalFlow> d_pyrLK_dense = cuda::DensePyrLKOpticalFlow::create(
Size(winSize, winSize), maxLevel, iters);
GpuMat d_flow(frame0.size(), CV_32FC2);
d_pyrLK_dense->calc(d_frame0Gray, d_frame1Gray, d_flow);
// Draw arrows
......@@ -171,9 +307,12 @@ int main(int argc, const char* argv[])
download(d_status, status);
drawArrows(frame0, prevPts, nextPts, status, Scalar(255, 0, 0));
imshow("PyrLK [Sparse]", frame0);
// Draw flows
showFlow("PyrLK [Dense] Flow Field", d_flow);
waitKey();
return 0;
......
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