Merge pull request #141 from jet47/gpu-pyrlk-fix

modules/gpu/src/pyrlk.cpp

@@ -200,6 +200,9 @@ void cv::gpu::PyrLKOpticalFlow::dense(const GpuMat& prevImg, const GpuMat& nextI
         pyrDown(nextPyr_[level - 1], nextPyr_[level]);
     }
 
+    uPyr_.resize(2);
+    vPyr_.resize(2);
+
     ensureSizeIsEnough(prevImg.size(), CV_32FC1, uPyr_[0]);
     ensureSizeIsEnough(prevImg.size(), CV_32FC1, vPyr_[0]);
     ensureSizeIsEnough(prevImg.size(), CV_32FC1, uPyr_[1]);