На картинке ниже показано конкретное исключение, которое я получаю. Я не совсем уверен, почему у меня возникла именно эта проблема, так как я собрал все в одном каталоге, поэтому там есть файл библиотеки. Из того, что я понимаю, это как-то связано с тем, что я возвращаю своему методу main из моей функции c ++.
По сути, я пытаюсь передать имя (printId) распознанного человека в виде строки из моей функции c ++ в java.
Изображение командной строки:
Вот мой код C ++:
#include <jni.h>
#include <iostream>
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/core/core.hpp"
#include "opencv2/opencv.hpp"
#include "opencv2/objdetect.hpp"
#include "opencv2/face.hpp"
#include "opencv2/face/facerec.hpp"
#include <vector>
#include <string>
#include "recognitionJNI.h"
#include <fstream>
#include <sstream>
using namespace cv;
using namespace std;
String face_cascade_name = "/Users/greg/Downloads/opencv-3.4.2/data/haarcascades/haarcascade_frontalface_alt.xml";
CascadeClassifier face_cascade;
String fn_csv = "/Users/greg/Desktop/faceBuild/faceRecognition/faceRecognition/csv.txt";
//User Defined Function for reading csv
static void read_csv(const string& filename, vector<Mat>& images, vector<int>& labels, char separator = ';') {
ifstream file(filename.c_str(), ifstream::in); //opens file for reading
if(!file) {
cout << "ERROR: There was a problem loading the csv file" << endl;
}
string line, path, classlabel;
while(getline(file,line)) {
stringstream liness(line);
getline(liness, path, separator); //read stream object up to the semicolon
getline(liness, classlabel); //read the rest of stream object up to null terminated character
//make sure that the filepath and userID are not empty
if(!path.empty() && !classlabel.empty()) {
images.push_back(imread(path,0)); //appends grayscale image to images vector
labels.push_back(atoi(classlabel.c_str())); //appends userID to labels vector
}
}
}
JNIEXPORT jstring JNICALL Java_testJNIString_userName(JNIEnv *env, jobject thisObj, jstring inJNIStr) {
const char *inCStr = env->GetStringUTFChars(inJNIStr, NULL);
if (NULL == inCStr) return NULL;
string outCppStr;
cout << "In C++, the received string is: " << inCStr << endl;
env->ReleaseStringUTFChars(inJNIStr, inCStr);
string printId;
vector<Mat> images; //This vector will hold the images
vector<int> labels; //This vector will hold the userID
//read the csv file contain image paths and userID's
try {
read_csv(fn_csv, images, labels);
} catch (Exception& e) {
cerr << "Error opening file\"" << fn_csv << "\". Reason: " << e.msg << endl;
exit(1);
}
//we'll need to resize the images to their origal size
//These two lines capture the length and width of the mat object
int im_width = images[0].cols;
int im_height = images[0].rows;
for(int j=0; j < images.size(); j++) {
resize(images[j],images[j],Size(im_width, im_height),1.0,1.0,INTER_CUBIC);
}
//int numComponents = 2;
//double threshold = 10.0;
//creats a faceRecognizer to train with given images
Ptr<cv::face::FisherFaceRecognizer> model = cv::face::FisherFaceRecognizer::create();
model->train(images, labels);
string camera_msg = "No camera found";
Mat webcam; // creates Mat object for to store frames
VideoCapture cap(0); // opens default webcam
if(!cap.isOpened()) {
return env->NewStringUTF(camera_msg.c_str());
}
face_cascade.load(face_cascade_name); //loads xml file into classifier
//load capture device into Mat object
while (cap.read(webcam)) {
vector<Rect> faces;
Mat frame_gray; //will be used to store grayscale copy of webcam
cvtColor(webcam, frame_gray, COLOR_BGR2GRAY); //coverts Mat object frames into grayscale
equalizeHist(frame_gray, frame_gray); //maps input distrubution to more uniform distribution
//locate the faces in the frame
face_cascade.detectMultiScale(frame_gray, faces, 1.1, 5, 0|CASCADE_SCALE_IMAGE,Size(30,30));
for(size_t i=0; i < faces.size(); i++) {
Rect face_i = faces[i]; //process faces by frame
Mat face = frame_gray(face_i); //takes the face from the live images
//resize faces for prediction
Mat face_resized;
resize(face,face_resized,Size(im_width, im_height),1.0,1.0,INTER_CUBIC);
int prediction = model->predict(face_resized); //predict based on resize faces
if(prediction == 1 ) {
printId = "Matthew";
}
else if (prediction == 2) {
printId = "Greg";
return env->NewStringUTF(printId.c_str());
}
else if(prediction != 1 || 2 ){
printId = "Unknown";
}
rectangle(webcam, face_i, CV_RGB(0,255,0), 1); //draws a rectangle around the face
string box_text = "Prediction = " + printId;
int pos_x = std::max(face_i.tl().x - 10, 0);
int pos_y = std::max(face_i.tl().y - 10, 0);
putText(webcam, box_text, Point(pos_x,pos_y), FONT_HERSHEY_PLAIN, 1.0, CV_RGB(0,255,0), 1);
}
imshow("Webcam", webcam);
waitKey(1);
destroyAllWindows();
}
return env->NewStringUTF(printId.c_str());
}
Вот мой код Java:
public class recognitionJNI{
static {
System.loadLibrary("recogjni");
}
private native String userName(String msg);
public static void main(String args[]) {
String result = new recognitionJNI().userName("Pass arg from c++ function");
System.out.println(result);
}
}