c++ - OPENCV CUDA -- getCudaEnabledDeviceCount 返回 0

Question

我刚接触 opencv 和 cuda。我使用 opencv2.4.6 和 CUDA4.2。我已经成功地用cuda编译了opencv。当我使用代码时:

int cuda_count;
cudaError_t error = cudaGetDeviceCount( &cuda_count );

它返回 cudaSuccess 和 cuda_count=1但是，当我使用代码时:

int num_devices = cv::gpu::getCudaEnabledDeviceCount();

num_devices 返回 0为什么？

我的完整代码是:

int main()
{

int num_devices = cv::gpu::getCudaEnabledDeviceCount();

    int cuda_count;
    cudaError_t error = cudaGetDeviceCount( &cuda_count );

    if(num_devices <=0 )
    {
        std::cerr << "no" << std::endl;
        return -1;
    }

    int enable_devivce_id = -1;
}

Answer 1

你肯定编译过没有CUDA支持的OpenCV

gpu::getCudaEnabledDeviceCount Returns the number of installed CUDA-enabled devices.

C++: int gpu::getCudaEnabledDeviceCount()

Use this function before any other GPU functions calls. If OpenCV is compiled without GPU support, this function returns 0.