Bug #1823 : fixed patch size calculation in PyrLKOpticalFlow

modules/gpu/src/pyrlk.cpp

@@ -124,6 +124,29 @@ void cv::gpu::PyrLKOpticalFlow::buildImagePyramid(const GpuMat& img0, vector<Gpu
     }
 }
 
+namespace
+{
+    void calcPatchSize(cv::Size winSize, int cn, dim3& block, dim3& patch)
+    {
+        winSize.width *= cn;
+
+        if (winSize.width > 32 && winSize.width > 2 * winSize.height)
+        {
+            block.x = 32;
+            block.y = 8;
+        }
+        else
+        {
+            block.x = block.y = 16;
+        }
+
+        patch.x = (winSize.width  + block.x - 1) / block.x;
+        patch.y = (winSize.height + block.y - 1) / block.y;
+
+        block.z = patch.z = 1;
+    }
+}
+
 void cv::gpu::PyrLKOpticalFlow::sparse(const GpuMat& prevImg, const GpuMat& nextImg, const GpuMat& prevPts, GpuMat& nextPts, GpuMat& status, GpuMat* err)
 {
     using namespace cv::gpu::device::pyrlk;
@@ -142,19 +165,8 @@ void cv::gpu::PyrLKOpticalFlow::sparse(const GpuMat& prevImg, const GpuMat& next
 
     const int cn = prevImg.channels();
 
-    dim3 block;
-
-    if (winSize.width * cn > 32)
-    {
-        block.x = 32;
-        block.y = 8;
-    }
-    else
-    {
-        block.x = block.y = 16;
-    }
-
-    dim3 patch((winSize.width * cn + block.x - 1) / block.x, (winSize.height + block.y - 1) / block.y);
+    dim3 block, patch;
+    calcPatchSize(winSize, cn, block, patch);
 
     CV_Assert(derivLambda >= 0);
     CV_Assert(maxLevel >= 0 && winSize.width > 2 && winSize.height > 2);

samples/gpu/pyrlk_optical_flow.cpp

@@ -152,11 +152,16 @@ void getFlowField(const Mat& u, const Mat& v, Mat& flowField)
 int main(int argc, const char* argv[])
 {
     const char* keys =
-       "{ h  | help           | false | print help message }"
-       "{ l  | left           |       | specify left image }"
-       "{ r  | right          |       | specify right image }"
-       "{ g  | gray           | false | use grayscale sources [PyrLK Sparse] }"
-       "{ p  | points         | 4000  | specify points count [GoodFeatureToTrack] }";
+        "{ h            | help           | false | print help message }"
+        "{ l            | left           |       | specify left image }"
+        "{ r            | right          |       | specify right image }"
+        "{ gray         | gray           | false | use grayscale sources [PyrLK Sparse] }"
+        "{ win_size     | win_size       | 21    | specify windows size [PyrLK] }"
+        "{ max_level    | max_level      | 3     | specify max level [PyrLK] }"
+        "{ iters        | iters          | 30    | specify iterations count [PyrLK] }"
+        "{ deriv_lambda | deriv_lambda   | 0.5   | specify deriv lambda [PyrLK] }"
+        "{ points       | points         | 4000  | specify points count [GoodFeatureToTrack] }"
+        "{ min_dist     | min_dist       | 0     | specify minimal distance between points [GoodFeatureToTrack] }";
 
     CommandLineParser cmd(argc, argv, keys);
 
@@ -178,7 +183,12 @@ int main(int argc, const char* argv[])
     }
 
     bool useGray = cmd.get<bool>("gray");
+    int winSize = cmd.get<int>("win_size");
+    int maxLevel = cmd.get<int>("max_level");
+    int iters = cmd.get<int>("iters");
+    double derivLambda = cmd.get<double>("deriv_lambda");
     int points = cmd.get<int>("points");
+    double minDist = cmd.get<double>("min_dist");
 
     Mat frame0 = imread(fname0);
     Mat frame1 = imread(fname1);
@@ -210,7 +220,7 @@ int main(int argc, const char* argv[])
 
     // goodFeaturesToTrack
 
-    GoodFeaturesToTrackDetector_GPU detector(points, 0.01, 0.0);
+    GoodFeaturesToTrackDetector_GPU detector(points, 0.01, minDist);
 
     GpuMat d_frame0Gray(frame0Gray);
     GpuMat d_prevPts;
@@ -221,6 +231,12 @@ int main(int argc, const char* argv[])
 
     PyrLKOpticalFlow d_pyrLK;
 
+    d_pyrLK.winSize.width = winSize;
+    d_pyrLK.winSize.height = winSize;
+    d_pyrLK.maxLevel = maxLevel;
+    d_pyrLK.iters = iters;
+    d_pyrLK.derivLambda = derivLambda;
+
     GpuMat d_frame0(frame0);
     GpuMat d_frame1(frame1);
     GpuMat d_frame1Gray(frame1Gray);