Function main

compute/example/opencv_convolution.cpp:100–265

This example shows how to read two images or use camera with OpenCV, transfer the frames to the GPU, and apply a convolution written in OpenCL

// with OpenCV, transfer the frames to the GPU,
// and apply a convolution written in OpenCL
int main(int argc, char *argv[])
{
    ///////////////////////////////////////////////////////////////////////////

    // setup the command line arguments
    po::options_description desc;
    desc.add_options()
            ("help",  "show available options")
            ("camera", po::value<int>()->default_value(-1),
                                 "if not default camera, specify a camera id")
            ("image", po::value<std::string>(), "path to image file");

    // Parse the command lines
    po::variables_map vm;
    po::store(po::parse_command_line(argc, argv, desc), vm);
    po::notify(vm);

    //check the command line arguments
    if(vm.count("help"))
    {
        std::cout << desc << std::endl;
        return 0;
    }

    ///////////////////////////////////////////////////////////////////////////

    //OpenCV variables
    cv::Mat cv_mat;
    cv::VideoCapture cap; //OpenCV camera handle.

    //Filter Variables
    float filter[9] =  {
                -1.0,      0.0,      1.0,
                -2.0,      0.0,      2.0,
                -1.0,      0.0,      1.0,
                };

    // The convolution filter is 3x3
    int filterWidth = 3;

    //OpenCL variables
    // Get default device and setup context
    compute::device gpu = compute::system::default_device();
    compute::context context(gpu);
    compute::command_queue queue(context, gpu);
    compute::buffer dev_filter(context, sizeof(filter),
                               compute::memory_object::read_only |
                               compute::memory_object::copy_host_ptr,
                               filter);

    compute::program filter_program =
            compute::program::create_with_source(source, context);

    try
    {
        filter_program.build();
    }
    catch(compute::opencl_error e)