Question

参考Sample：facedetection，本机代码如下：

inline void vector_Rect_to_Mat(vector<Rect>& v_rect, Mat& mat)
{
mat = Mat(v_rect, true);
}


JNIEXPORT void JNICALL Java_org_opencv_samples_facedetect_DetectionBasedTracker_nativeDetect
(JNIEnv * jenv, jclass, jlong thiz, jlong imageGray, jlong faces)
{
LOGD("Java_org_opencv_samples_facedetect_DetectionBasedTracker_nativeDetect enter");
try
{
    vector<Rect> RectFaces;
    ((DetectionBasedTracker*)thiz)->process(*((Mat*)imageGray));
    ((DetectionBasedTracker*)thiz)->getObjects(RectFaces);
    for(int i=0; i<RectFaces.size(); i++)
    {
        Point p,k;
        p.x = ((Rect)RectFaces[i]).x;
        p.y = ((Rect)RectFaces[i]).y;
        k.x = ((Rect)RectFaces[i]).x + ((Rect)RectFaces[i]).width;
        k.y = ((Rect)RectFaces[i]).y + ((Rect)RectFaces[i]).height;
        rectangle(*((Mat*)imageGray), p, k,Scalar(0,255,255, 255), -1, 8);
    }
    vector_Rect_to_Mat(RectFaces, *((Mat*)faces));
}
catch(cv::Exception& e)
{
    LOGD("nativeCreateObject caught cv::Exception: %s", e.what());
    jclass je = jenv->FindClass("org/opencv/core/CvException");
    if(!je)
        je = jenv->FindClass("java/lang/Exception");
    jenv->ThrowNew(je, e.what());
}
catch (...)
{
    LOGD("nativeDetect caught unknown exception");
    jclass je = jenv->FindClass("java/lang/Exception");
    jenv->ThrowNew(je, "Unknown exception in JNI code{highgui::VideoCapture_n_1VideoCapture__()}");
}
LOGD("Java_org_opencv_samples_facedetect_DetectionBasedTracker_nativeDetect exit");

}

现在，提取的（多个）ROI将位于向量上的Rect容器中，然后传递给名为“faces”的Java类型MatOfRect。假设问题是通过JNI通过地址传递的此Java类型的反向转换，以将ROI从“面”重新提取到向量roi。

OpenCV MatOfRect JNI类型转换

0 个答案: