#include <cmath> #include <iostream> #include "opencv2/core.hpp" #include <opencv2/core/utility.hpp> #include "opencv2/highgui.hpp" #include "opencv2/imgproc.hpp" #include "opencv2/cudaimgproc.hpp" using namespace std; using namespace cv; using namespace cv::cuda; static void help() { cout << "This program demonstrates line finding with the Hough transform." << endl; cout << "Usage:" << endl; cout << "./gpu-example-houghlines <image_name>, Default is ../data/pic1.png\n" << endl; } int main(int argc, const char* argv[]) { const string filename = argc >= 2 ? argv[1] : "../data/pic1.png"; Mat src = imread(filename, IMREAD_GRAYSCALE); if (src.empty()) { help(); cout << "can not open " << filename << endl; return -1; } Mat mask; cv::Canny(src, mask, 100, 200, 3); Mat dst_cpu; cv::cvtColor(mask, dst_cpu, COLOR_GRAY2BGR); Mat dst_gpu = dst_cpu.clone(); vector<Vec4i> lines_cpu; { const int64 start = getTickCount(); cv::HoughLinesP(mask, lines_cpu, 1, CV_PI / 180, 50, 60, 5); const double timeSec = (getTickCount() - start) / getTickFrequency(); cout << "CPU Time : " << timeSec * 1000 << " ms" << endl; cout << "CPU Found : " << lines_cpu.size() << endl; } for (size_t i = 0; i < lines_cpu.size(); ++i) { Vec4i l = lines_cpu[i]; line(dst_cpu, Point(l[0], l[1]), Point(l[2], l[3]), Scalar(0, 0, 255), 3, LINE_AA); } GpuMat d_src(mask); GpuMat d_lines; { const int64 start = getTickCount(); Ptr<cuda::HoughSegmentDetector> hough = cuda::createHoughSegmentDetector(1.0f, (float) (CV_PI / 180.0f), 50, 5); hough->detect(d_src, d_lines); const double timeSec = (getTickCount() - start) / getTickFrequency(); cout << "GPU Time : " << timeSec * 1000 << " ms" << endl; cout << "GPU Found : " << d_lines.cols << endl; } vector<Vec4i> lines_gpu; if (!d_lines.empty()) { lines_gpu.resize(d_lines.cols); Mat h_lines(1, d_lines.cols, CV_32SC4, &lines_gpu[0]); d_lines.download(h_lines); } for (size_t i = 0; i < lines_gpu.size(); ++i) { Vec4i l = lines_gpu[i]; line(dst_gpu, Point(l[0], l[1]), Point(l[2], l[3]), Scalar(0, 0, 255), 3, LINE_AA); } imshow("source", src); imshow("detected lines [CPU]", dst_cpu); imshow("detected lines [GPU]", dst_gpu); waitKey(); return 0; }