dlib android 识别时间,在android 平台编译并使用dlib进行人脸68个特征检测

上一篇文章描述了在ndk环境下编译opencv JNI用于简单的图像处理的流程。本篇文章主要讲述在Android环境下基于opencv + dlib 进行人脸68个特征点提取。

分别下载dlib库和opencv库，网站如下：

http://dlib.net/files/

opencv的下载请参照上篇文章。

新建Android Project ，新建时要选中include c++ support。

工程新建好后，按照如下操作：

在这里插入图片描述

4 .修改CMakeLists.txt 文件内容，如下：

修改build.gradle 文件内容：

6 .在代码中加载静态库，加载时要注意顺序：

java层代码如下：

public class FaceActivity extends AppCompatActivity implements CameraBridgeViewBase.CvCameraViewListener2 {

private JavaCameraView cameraView;

private Mat rgba;

static {

System.loadLibrary(“opencv_java3”);

System.loadLibrary(“native-lib”);

}

@Override

protected void onCreate(@Nullable Bundle savedInstanceState) {

super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); //设置无标题

// getWindow().setFlags(WindowManager.LayoutParams.FILL_PARENT, WindowManager.LayoutParams.FILL_PARENT); //设置全屏

setContentView(R.layout.activity_face);

cameraView = findViewById(R.id.javaCameraView);

cameraView.setCvCameraViewListener(this);

faceinit();

}

public void onCameraViewStarted(int width, int height) {

//定义Mat对象

rgba = new Mat(width, height, CvType.CV_8UC3);

}

public void onCameraViewStopped() {

rgba.release();

}

public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame) {

rgba = inputFrame.rgba();

//得到当前一帧图像的内存地址

long addr = rgba.getNativeObjAddr();

//对一帧图像进行处理

nativeRgba(addr);

//得到一帧灰度图

// rgba = inputFrame.gray();

return rgba;

}

@Override

protected void onResume() {

super.onResume();

if (!OpenCVLoader.initDebug()) {

} else {

cameraView.enableView();

}

}

@Override

protected void onPause() {

super.onPause();

if (cameraView != null) {

cameraView.disableView();

}

}

@Override

protected void onDestroy() {

super.onDestroy();

if (cameraView != null) {

cameraView.disableView();

}

}

public static native void nativeRgba(long jrgba);

public static native void faceinit();

}

8. jni层代码如下：

9.

extern “C” float getDistance(CvPoint pointO, CvPoint pointA)

{

float distance;

distance = powf((pointO.x - pointA.x), 2) + powf((pointO.y - pointA.y), 2);

distance = sqrtf(distance);

return distance;

}

extern “C” JNIEXPORT void JNICALL Java_com_facetest_FaceActivity_faceinit(

JNIEnv *env, jclass obj){

LOGD("------------JNI to nativeRgba 1 ");

deserialize("/sdcard/shape_predictor_68_face_landmarks.dat") >> pose_model;

detector = get_frontal_face_detector();

}

extern “C” JNIEXPORT void JNICALL Java_com_facetest_FaceActivity_nativeRgba(

JNIEnv *env, jclass obj, jlong jrgba)

{

Mat &img = *(Mat*)jrgba;

Mat out;

int A = 0,B = 0,C = 0;

// cvtColor(img,out,COLOR_RGBA2GRAY);

clock_t t1 = 0,t2 = 0;

dlib::array2darrimg(img.rows, img.cols);

for(int i=0; i < img.rows; i++)

{

for(int j=0; j < img.cols; j++)

{

arrimg[i][j].blue = img.at< cv::Vec3b>(i,j)[0];

arrimg[i][j].green=img.at< cv::Vec3b>(i,j)[1];

arrimg[i][j].red = img.at< cv::Vec3b>(i,j)[2];

}

}

t1 = clock();

std::vectorfaces= detector(arrimg);

t2 = clock();

std::vectorshapes;

for (unsigned long i = 0; i < faces.size(); ++i)

shapes.push_back(pose_model(arrimg, faces[i]));

if (!shapes.empty()) {

for (int i = 0; i < 68; i++) {

circle(img, cvPoint(shapes[0].part(i).x(), shapes[0].part(i).y()), 3, cv::Scalar(0, 0,255), -1);

}

//用于计算眼宽比

A = getDistance(Point(shapes[0].part(37).x(),shapes[0].part(37).y()),Point(shapes[0].part(41).x(),shapes[0].part(41).y()));

B = getDistance(Point(shapes[0].part(38).x(),shapes[0].part(38).y()),Point(shapes[0].part(40).x(),shapes[0].part(40).y()));

C = getDistance(Point(shapes[0].part(36).x(),shapes[0].part(36).y()),Point(shapes[0].part(39).x(),shapes[0].part(39).y()));

char temp[32] = {0 };

sprintf(temp,"rightEye:%f time: %lu",((A+B)/(C*2.0)),(t2-t1));

putText(img, temp, Point(10,30), FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 0, 0, 255));

}