java调用dll进行人脸识别（JNI的使用）

http://blog.csdn.net/jiben071/article/details/6011019

1.JNI部分

调用JNI基类（JNIBase.java）

 

 package lveyo.bcndyl.jni.opencv;
 public class JNIBase {

     public JNIBase(){}

     public JNIBase(String libraryName){
         loadLibrary(libraryName);
     }

     private static void loadLibrary(String libraryName){
         System.loadLibrary(libraryName);
     }

 }

实现基类(JNIOpencv.java)

 package lveyo.bcndyl.jni.opencv;

 public class JNIOpencv extends JNIBase{

     public JNIOpencv (String libraryName){
         super(libraryName);
     }

     public JNIOpencv(){
         System.loadLibrary("jniOpenCV");
     }

     public native int[] detectFace(int minFaceWidth, int minFaceHeight,
                                    String cascade, String filename);

 }

 

2.编译文件

运行——>cmd——>进入java源文件夹

javac -d . JNIBase.java

javac -d . JNIOpencv.java

javah lveyo.bcndyl.jni.opencv.JNIOpencv //生成lveyo_bcndyl_jni_opencv_JNIOpencv.h头文件

 

二、visual C++6.0

3.建立工程（选择win32 Dynamic-Link Library）

tools---->Options---->Drectories(添加以下目录)

 C:/jdk1.6/INCLUDE        //根据具体jdk安装目录确定
 C:/jdk1.6/INCLUDE/WIN32

4.点击工程右键（先确定自己已经安装和配置好OpenCV，可以到OpenCV中文官网参考visualC++6.0配置安装opencv步骤）

选择“设置”，下拉选择“所有配置”，在右方区域点击连接，在对象/库模块下添加

cxcore.lib cv.lib ml.lib cvaux.lib highgui.lib cvcam.lib

5.新建头文件veyo_bcndyl_jni_opencv_JNIOpencv.h

添加在编译时生成的头文件代码：

 #include <jni.h>

 #ifndef _Included_lveyo_bcndyl_jni_opencv_JNIOpencv
 #define _Included_lveyo_bcndyl_jni_opencv_JNIOpencv
 #ifdef __cplusplus
 extern "C" {
 #endif
 JNIEXPORT jintArray JNICALL Java_lveyo_bcndyl_jni_opencv_JNIOpencv_detectFace
   (JNIEnv *, jobject, jint, jint, jstring, jstring);

 #ifdef __cplusplus
 }
 #endif
 #endif

6.新建jniOpenCV.cpp程序文件（检测主程序）

 //#include "stdafx.h"
 #include <jni.h>
 #include "lveyo_bcndyl_jni_opencv_JNIOpencv.h"
 #include "cv.h"
 #include "highgui.h"

 JNIEXPORT jintArray JNICALL Java_lveyo_bcndyl_jni_opencv_JNIOpencv_detectFace
   (JNIEnv *env, jobject obj, jint width, jint height, jstring cascade, jstring filename)
 {
     const char *str_cascade, *str_filename;
     str_cascade = env->GetStringUTFChars(cascade, false);
     str_filename = env->GetStringUTFChars(filename, false);

     jintArray faceArray;
     CvHaarClassifierCascade *cv_cascade = (CvHaarClassifierCascade*)cvLoad( str_cascade );
     IplImage *image = cvLoadImage( str_filename, 1 );

     if(image!=0){

         CvMemStorage* storage = cvCreateMemStorage(0);
         CvSeq* faces;

         //double t = (double)cvGetTickCount();
         /* use the fastest variant */
         faces = cvHaarDetectObjects( image, cv_cascade, storage, 1.2, 2,
                                    CV_HAAR_DO_CANNY_PRUNING, cvSize(width, height) );
         //t = (double)cvGetTickCount() - t;
         //printf( "detection time = %gms/n", t/((double)cvGetTickFrequency()*1000.) );


         const int total = faces->total;

         faceArray = env-> NewIntArray(4*total);
         jint faceBuf[4];

         for( int i = 0; i < total; i++ )
         {
             CvRect face_rect = *(CvRect*)cvGetSeqElem( faces, i );
             int pointX = face_rect.x;
             int pointY = face_rect.y;
             int faceWidth = face_rect.width;
             int faceHeight = face_rect.height;

             //printf("i %d, x %d, y %d, width %d, height %d/n",
                         //        i,pointX,pointY,faceWidth,faceHeight);


             faceBuf[0] = pointX;
             faceBuf[1] = pointY;
             faceBuf[2] = faceWidth;
             faceBuf[3] = faceHeight;


             env->SetIntArrayRegion(faceArray,i*4,4,faceBuf);

         }

         cvReleaseMemStorage( &storage );
         cvReleaseImage( &image );
     }
     cvReleaseHaarClassifierCascade( &cv_cascade );


     env->ReleaseStringUTFChars(cascade, str_cascade);
     env->ReleaseStringUTFChars(filename, str_filename);
     return faceArray;
 }

然后进行编译、组建

7.进入c++源文件夹把DEBUG里生成的jniOpenCV.dll拖入D:/mylib里（具体原因参考我的另一篇文章《java调用dll（JNI的使用）》）同时把Opencv的C:/Program Files/OpenCV/bin目录下的所有dll文件拖入D:/mylib中(java程序调用需要)

 

8.D:/mylib中需要拖入haarcascade_frontalface_alt2.xml文件（OpenCV提供的人脸特征文件）

 

 

三、回到java部分

9.新建Test.java(进行程序测试)

注意先在D盘放入人物图片

 package lveyo.bcndyl.jni.opencv;

 public class Test {

     public static void main(String[] args) {

         //初始化JNI调用类JNIOpencv
         JNIOpencv open = new JNIOpencv("jniOpenCV");

         //要检测的图片文件
         String filename = "d:/80010.jpg";

         //OpenCv提供的人间的特征文件
         String cascade = "d:/haarcascade_frontalface_alt2.xml";

         //人脸检测，前两个参数为可检测的最小人脸的宽度和高度
         //返回值为人脸在图中的坐标和宽高，{x, y, width, height}
         int[] faces = open.detectFace(40, 40, cascade, filename);
         if(faces != null && faces.length!=0){

             //返回的人脸总数
             System.out.println( "faces " + faces.length/4 );

             //分别输出每个人脸的坐标信息
             for (int temp : faces) {
                 System.out.println(temp);
             }
         }
     }
 }

运行程序